Spartan RV Chassis Owners Training Academy

NIRVC is proud to host the Spartan RV Chassis Owners Training Academy! These multi-day events offer comprehensive training for chassis maintenance and upkeep, overall RV inspection and service, and more. 

Participants receive hands-on help with their RV, learning the nuances of chassis sub-systems such as electrical, air suspension and more. On top of the invaluable knowledge, these sessions offer a great opportunity to connect with fellow RVers!

Spartan RV Chassis are the basis of many Class A Entegra, Newmar and Jayco RVs. Your motorhome does NOT have to be purchased from NIRVC to take advantage of this fantastic program.

Topics include:

  • An overview of chassis maintenance and upkeep
  • A personal inspection of your coach with a qualified Spartan RV Chassis Technician
  • Personal, on-the-road drive time with a certified instructor including basic driver guidelines, hazard awareness and avoidance, as well as control and recovery and the driver’s role
  • Instruction on weighing your RV and adjusting tire pressures accordingly
  • How to access and purchase Spartan RV Chassis aftermarket parts and accessories
  • How to operate chassis air systems
  • Information on customer support and warranty information
  • Familiarity with chassis suspensions, chassis electrical systems
  • Chassis troubleshooting
  • Weighing of your coach and tire pressures set

    Upcoming Spartan RV Chassis Owners Training Academy Sessions at NIRVC:

    • December 12-14, 2023
      NIRVC – Phoenix

    Welcome to RV U! Our New Podcast Hosted by Angie Morell is Live

    Class is in session at RV U! Tune into the premier insider podcast brought to you by National Indoor RV Centers! Host and renowned RV pro Angie Morell sits down with industry experts, icons and influencers to chat about a variety of entertaining topics, including the latest RV trends, new and popular products, helpful tips, stories about guests’ adventures and more. Whether you’re an incoming freshman or have a PhD in RVing, there’s room for you in the classroom.

    New episodes will be available every Wednesday, so be sure to subscribe to RV U on your favorite podcast platforms below.

    Spotify Logo
    Pandora Logo
    Amazon Music Logo
    Audible Logo
    iHeart Radio Logo

    RV Hydronic Heating Systems

    What are hydronic heating systems and how do they work in your RV?

    Hydronic heating systems are rapidly becoming the heating system of choice on diesel pushers versus forced air furnaces. Hydronic heat offers even heat distribution and moist, comfortable heating. It utilizes a boiler that pumps antifreeze through a series of heat exchangers located throughout the coach. It also provides domestic hot water heating, eliminating the need for a traditional hot water heater. The two brands that are common in the RV industry are Aqua-Hot and Oasis.

    RV Heat Sources

    A hydronic heating system can be powered by a diesel burner as well as an electric heating element. In some cases a propane fired boiler is used in smaller RVs but for this article we’ll just stick to the diesel fired units common to most diesel pushers. Diesel fuel has more BTU per gallon than propane. Plus, the fuel tank is of greater capacity because it utilizes the coach’s diesel tank rather than a smaller LP tank mounted in the coach. Not only is this more cost efficient but it also greatly extends the run time between refueling.

    Propane has a BTU rating of 91,500 BTU per gallon while #2 diesel fuel is rated at 139,200 BTU per gallon. Operating a 50,000 BTU burner on propane for 8 hours will require 4.37 gallons of propane while running that same burner on diesel fuel will only require 2.87 of fuel due to the higher BTU content of diesel fuel. If your LP fired burner is fed from a 32 gallon propane tank you can run that burner for a maximum of 58.56 hours while running a diesel burner from a 100 gallon fuel tank will allow you 278.4 hours of run time until you’ll need to refuel.

    In addition to the diesel burner, hydronic heating systems also have an electrical heating element that can be used. A typical 1,650 watt heating element can deliver 5,630 BTU. This isn’t as great as a 50 KBTU diesel burner but it is capable of heating the coach when it’s cool (but not cold) out. It’s also possible to operate both the burner and the electric element at the same time for additional heating capacity.

    Most units are also equipped with a Motoraide or engine assist connection. This allows the hot engine coolant to be used to add additional free heat to the boiler when driving. This engine to boiler loop can also be used as an engine preheat that uses the boiler’s heat to preheat the engine for cold start assistance if so equipped.

    Aqua-Hot vs. Oasis

    Both the Aqua-Hot and Oasis systems are similar in operation. They both utilize a boiler to heat up antifreeze so that it can circulate through a closed heating loop. There are heat exchangers placed in various locations in the loop to provide heat to the coach interior as well as any basement area that needs to be protected from freezing. They also provide domestic hot water but there are a number of differences in how the units are constructed to meet these needs.

    The popular Aqua-Hot 450 supports a claimed 50,000 BTU burner, although the latest advertised specs state 65,000 BTU, and a 6 gallon boiler tank. It also sports a 1,650 watt electric heating element on a 20 amp breaker. Hot water temperature is always rated at a delta, which is the difference between the temperature of the incoming cold water to the outgoing heated water. The 450D is rated at a 60 degree delta at 1.5 GPM water flow. If the incoming water is frigidly cold then you’ll only be able to raise it by 60 degrees. If you exceed the 1.5 GPM flow rate you will also lose the ability to keep the antifreeze in the boiler tank from holding its heat so you’ll need to watch your water flow on those long hot showers or they will finish up as cold showers.

    For more more on RV water systems, read Mark’s blog, An RVers Guide To Water


    An Aqua-Hot 450D system.

    The Aqua-Hot system also will shut off the interior heat exchangers when hot water is being used so  that all available BTU can be dedicated to heating water. The interior heating will resume once the water flow stops. The Aqua-Hot claimed BTU ratings are suspect however . The burner uses a .35 GPM burner nozzle. Doing the math you can see that this is only 39,200 BTU per hour – not 50,000 BTU. 


    An Aqua-Hot 450D as installed in my Entegra Cornerstone.

    An opened-up view of the Aqua-Hot system.

    Oasis also makes a 50,000 BTU system called the Oasis NE, which uses a 7.5 gallon boiler tank. It utilizes a pair of 1,500 watt electric heating elements, producing up to 10,236 BTU on two 15 amp breakers. You can operate one or both at the same time. This will let you utilize the electric heat to a bit lower temperatures before needing to switch on the diesel burner. Hot water heating is also rated at a 65 degree delta at 1.5 GPM although the Oasis NE does not interrupt interior floor heat while hot water is being consumed. The burners use a .44 GPM fuel nozzle, which equates to a realistic 49,280 BTU.

    The Oasis NE system

    Oasis also makes a larger Oasis NE-S version. This slightly larger version is the ultimate in hydronic heating, with a claimed 85,000 BTU burner rating and a 13.75 gallon boiler tank. It has the same dual 1,500 watt heating elements as the Oasis NE but the 60 degree delta for hot water is now increased to 3 GPM with no floor heat interruption. The burner uses a 0.79 GPM burner nozzle.

    The above calculations are based upon an 80% factor in the BTU of diesel fuel. While diesel fuel does have 140,000 BTU per gallon about 20% of that is lost as heat in the exhaust, leaving 80%  to do the actual work of heating. So I used 112,000 BTU when doing the above calculations.


    An installed Oasis NE system in a Showhauler motorhome.


    Your system will have a few switches to operate the boiler. These switches may be rocker switches, or in a dedicated control panel or embedded in a multiplex control panel such as a VegaTouch screen. These switches are used to turn on the diesel burner and electric heating elements. There may also be a switch for an optional engine preheat feature if so equipped. These controls supply power to operate the boiler. If they are not on you won’t get any heat. Once the boiler heats up to its designated cutout temperature it will stop. Once the boiler’s temperature drops below the cut-in temperature it will start up again to raise the heat level of the boiler antifreeze.


    The diesel burner and electrical heating element are controlled by a switch panel.

    The antifreeze in the boiler is used to circulate through a couple of closed loops via circulating pumps. Interior heat exchangers are inserted into these loops at key locations to evenly distribute heat throughout the coach interior. These circulating pumps are controlled by the coach’s HVAC thermostat controls. Whenever the thermostat calls for heat, the circulating pumps will circulate hot antifreeze through the heating loop and heat exchangers. The fans on the heat exchangers will switch on to deliver the heat to the interior but only if the boiler is hot. This is to prevent blowing cold air from the heat exchangers if the antifreeze hasn’t warmed up yet. Once it is warmed up, the fans will engage and heat the coach interior. If the boiler cools down the fans will stop, allowing the boiler to regain its temperature before switching on again. When first starting up a hydronic system, you will have to wait a few minutes until the boiler warms up.

    These systems have two heating loops, each powered by a circulating pump. A number of heat exchangers can be connected to these loops and these heat exchangers are connected to up to 5 heating zones. One heating zone may be used for the main cabin interior heating while a second heating zone may be used for the bedroom and rear bath heating area. A third zone may be used for basement heat while a fourth zone may be used for hydronic floor heat, in the case of  an Entegra Coach. The layout of these zones and to which circulating loop they are assigned is up to the coach manufacturer’s discretion. Each zone will have individual thermostat control with remote sensors. This can be multiple thermostats, a multi-zone thermostat or part of a VegaTouch multiplex system. In many cases, there will be a separate manually-operated thermostat in the basement to control the basement zone that protects the fresh water system from freezing. If you just want to keep minimal heat in the coach, you will still need to leave either the electric heating element or diesel burner switched on or else you won’t get any heat.


    Many coaches utilize a separate thermostat to control the basement heat.

    The Motoraide loop to the engine will provide a bit of heat when driving. Typical BTU output for this is in the neighborhood of 10,000 BTU but will vary from coach to coach. It will keep the boiler hot so that you will have hot water when you stop and can give you a bit of interior heat but if it’s relatively cool out you will want to use the diesel burner as well. Still, the extra 10 KBTU is a help and will give you some free heat and save some diesel fuel. This system utilizes the engine’s water pump to circulate engine coolant through an internal heat exchanger inside the boiler via regular automotive heater hoses. You do not have to switch on any engine preheat pump for this to happen.

    The optional engine preheat feature utilizes the same heater hoses but adds a circulating pump that pumps the engine antifreeze in the opposite direction. This is used to provide heat from an operating hydronic heating system boiler to a cold engine to make it easier to start. Note that this is not part of the engine block heater, which is a second preheat device supplied by the chassis manufacturer. The hydronic preheat system will actually heat up your engine faster than the block heater because it has more BTU. You can also use it when you are parked in a place where you do not have access to electricity because you can run your boiler on diesel fuel in the middle of Alaska if you need to preheat your engine. This is an optional feature so it depends on if the coach manufacturer uses it. If you stay out of cold areas it may not be of much use for you.

    Hydronic systems also provide domestic hot water in addition to heat. The hot boiler antifreeze transfers heat to a coil that heats the fresh water as it passes through the coil on its way to your hot water faucets. A traditional water heater that uses a tank to store hot water will quickly run out of hot water once the tank is depleted so no long hot showers are possible. The hydronic system is a true on-demand system that will heat the water as it passes through the heating coil. The only caveat is that you have to limit the flow so that the boiler can keep up. The typical system has the ability to raise the water’s temperature 60 degrees over the temperature of the incoming water. If your water is very cold you’ll be limited in how hot you can get the water but if the incoming water is warmer you’ll be able to heat it to a higher temperature. Typically, this is rated at a 1.5 GPM flow rate. If you exceed that rate, the boiler won’t be able to keep up and as the boiler temperature begins to drop – so will the temperature of your hot water output. Using higher flow rates can work for a short time but if you really need a long hot shower, you’ll want to keep the flow rate beneath 1.5 GPM.


    Anything mechanical will require a bit of maintenance every now and then. A hydronic heating system isn’t a high-maintenance item but when you consider that these systems have a diesel-powered flame that heats a boiler and circulating pumps that cycle antifreeze through heat exchangers, there are a few points to watch for.

    A typical system requires an annual service, which pretty much centers on the diesel burner. The diesel burner pumps fuel through a small nozzle into the burner chamber and is ignited by a spark. The nozzle itself has a minute orifice that is designed for a specific flow rate and a precise conical pattern. During normal use, the diesel fuel that passes through the nozzle will wear out the orifice, resulting in excess diesel fuel flow. This excess fuel will cause fouling of the swirler flues that are designed to create the correct circular airflow inside the burner’s combustion chamber. The end result is that your hydronic heating system runs rich, causing stinky exhaust and puffs of smoke. This wear occurs from use, not time, so if you run your diesel burner quite often you might require service sooner than the arbitrary one year interval.


    The burner nozzle, electrodes and flame sensor are part of the annual service.

    The combustion chamber needs to be cleaned and vacuumed as part of the service..

    Nozzles cannot be cleaned but they are inexpensive and should be replaced. The annual service also entails replacing the fuel filter and a thorough inspection of the burner. It’s important to keep the burner head clean, especially the electrodes and flame sensor photocell. At the same time a good vacuuming of the combustion chamber and cleaning of the swirler to ensure the ports are clean is necessary. Finally, a quick check of the fuel pump pressure will ensure that everything is up to snuff.


    The fuel filter for the diesel burner needs to be changed annually.

    Assuming that your system is functioning without any major issues, the only thing left is the antifreeze. Hydronic heating systems do not use automotive antifreeze, which includes water pump lubricants, anti-corrosion inhibitors and other additives designed for engines as well as freeze protection. A hydronic heating system uses an antifreeze that protects against freeze damage but it is designed for the best heat transfer. While most automotive antifreeze is Ethylene Glycol (EG), hydronic systems require Propylene Glycol (PG). The correct antifreeze will be available from Camco or Century and they are labeled as GRAS, which means Generally Recognized As Safe because they are not toxic, unlike EG. Your hydronic heating system will be equipped with a poly overflow tank so that you can see the level in your boiler. If it becomes discolored and smells burnt, it may be time to have your RV tech flush the system and replace the antifreeze.

    While the boiler and heating loops are a sealed system, it always seems that they need a little topping off every now and then, so most owners carry a spare jug along. Pure antifreeze needs to be mixed with water about 50/50. Antifreeze is available in jugs filled with concentrated antifreeze that needs to be mixed with water or as a preformulated 50/50 mix. If you do buy the concentrated antifreeze, be sure to use distilled or deionized water when diluting it to a 50/50 mix to prevent minerals from tap water from accumulating in your hydronic system. You can dilute it a bit beyond the 50/50 mix which covers to -42F. In fact, the best heat transfer is at 60% water and 40% antifreeze. That will drop the freeze temperature a bit, but not significantly. A quick check of your antifreeze’s freeze point with a refractometer will verify your current freeze point. If the freeze point is too high, you can add a bit of concentrated antifreeze to bring the freeze protection level back to where it needs to be.

    Really, with a little bit of care and understanding you’ll be able to enjoy your hydronic heat for a long time.

    National Indoor RV Centers blogger Mark Quasius profile picture

    Mark Quasius is the founder of, the past Midwest editor of RV Magazine, writes for numerous RV-related publications and a regular Contributor to FMCA’s Family RVing Magazine. Mark and his wife Leann travel in their 2016 Entegra Cornerstone.

    RV Numbers – Ratings, Limits and Capacity

    Every RV has specific ratings, limits and capacities related to weight distibution. 

    We’ve all heard the saying – “It just looks like his number was up”. Well motorhomes have numbers too – lots of them in fact, which can be a bit confusing to a prospective RV buyer. It’s easy to view a spec sheet or brochure and understand how large the holding tanks are, how many gallons the fuel tank holds or how many BTUs the furnace puts out, but there is a wide array of chassis-related numbers that may take a while to grasp their meanings. Once you have narrowed down whether you want gas or diesel, a Class A or Class C and the approximate length you want, it’s important to understand the various weight ratings to ensure that the RV you are choosing is capable of operating safely within its design parameters. Following is a summary of those ratings that will help you to better understand what they mean.

    Gross Vehicle Weight Rating (GVWR)

    The Gross Vehicle Weight Rating, or GVWR, is usually the first number that anyone pays attention to on a motorhome. It represents just how big this RV is. In actuality, it represents how heavy an RV can be within safe design parameters – so it’s really a “not to exceed” weight rating. Every motorhome is designed with a chassis frame, tires, engine, suspension, brakes, transmission and other components to operate in a given environment. A heavier vehicle will have stronger components to prevent failure at higher weight loads and deliver satisfactory performance when in operation. If you load your coach up with full cargo, occupants, full fuel and water the total weight should not exceed the GVWR. This is why it’s important to weigh your coach when fully loaded to ensure that you do not exceed the GVWR of that motorhome. Note that this is the resting weight and does not count any towed vehicles or trailers other than the amount of any tongue weight resting on the hitch. Although, if you have a motorcycle carrier or golf cart mounted on your trailer hitch that weight may be a significant amount.

    Unloaded Vehicle Weight (UVW)

    The Unloaded Vehicle Weight, or UVW, represents the actual weight of the vehicle when empty as it left the factory. You may see this listed on some manufacturer brochures or webpages but keep in mind these are generalizations and your actual will vary according to what options are chosen on your coach. Your vehicle’s actual UVW will be shown on a placard within the motorhome. The UVW includes a full tank of fuel and any chassis related fluids, such as coolant and oil, but does not include any water or propane. Once you know your RV’s GVWR and the UVW, you can calculate the CCC.

    Sleeping Capacity Weight Rating (SCWR)

    The Sleeping Capacity Weight Rating, or SCWR, is calculated by multiplying the number of sleeping positions by 154 pounds. Every coach will state how many sleeping positions are in the coach. The RVIA came up with 154 lbs. as an average number. The SCWR number isn’t all that important any more, as we’ll see later.

    Cargo Carrying Capacity (CCC)

    The Cargo Carrying Capacity, or CCC, represents how much stuff you can carry. It’s calculated by subtracting the UVW from the GVWR and then subtracting the SCWR, weight of the fresh water in your coach and the weight of the propane. The end result is the cargo carrying capacity.

    It’s not the most useful because the SCWR is an arbitrary number at best. CCC is still used in towable RVs but is no longer used in motorhomes, being replaced by OCCC.

    Occupant and Cargo Carrying Capacity (OCCC)

    Occupant and Cargo Carrying Capacity, or OCCC, has been used in motorized RVs since 2008. It includes the weight of occupants, water and propane as well. If you have a pair of 250 lb. persons in their coach, a full tank of water (100 gallons equals 834 lbs.) and 100 lbs. of propane on board you’ll already have 1,434 lbs. used up and you haven’t yet loaded up any food, clothing or recreational equipment. Some motorhomes may only have a couple of  thousand pounds of cargo capacity while some of the large tag axle coaches may have over 10,000 lbs. It’s definitely something you need to consider and compare to your traveling habits when buying a motorhome.


    This example shows the OCCC as well as defining the weight of water used in its calculation.

    Gross Axle Weight Rating (GAWR)

    The Gross Axle Weight Rating, or GAWR, is a weight rating of an axle. You’ll have both a front axle GAWR as well as a rear axle GAWR. If you have a tag axle coach, you’ll also have a tag axle GAWR. Most of the time your two or three axle ratings will add up to the GVWR but that is not always the case. In some cases an axle may be rated higher but the GVWR of the coach itself will be less due to limitations of the suspension, brakes, etc.

    GAWRs come into play in regard to weight distribution. You may have a coach that is loaded up to the full GVWR, but if the cargo weight isn’t distributed evenly you may have one axle overweight while the other end of the coach is lightly loaded. This can lead to excessive stress on the suspension components and tires that are overloaded. This underscores the importance of having your motorhome weighed on scales when fully loaded. Ideally, you should have a 4-corner weighing at a facility such as National Indoor RV Centers. That will show you if you have any side-to-side imbalance where you may need to shift some cargo from one side to the other. But if that’s not possible, at least have a per-axle scale reading taken at a truck stop.

    As a rule of thumb, single rear axle coaches tend to have most of the weight on the rear axle. The Federal Bridge Law limited the maximum weight of any axle to 20,000 lbs. This caused issues with the larger 37-40’ diesel pushers because all of the new amenities and ceramic tile floors added too much weight to the rear axle, leaving the front axle lightly loaded. Fortunately, the NHTSA changed the rules in 2008, allowing motorhomes to have higher axle rating. Currently most of the larger single-axle diesel pushers are equipped with upgraded 24K rated axles to restore some cargo capacity. If you have a tag axle coach, just the opposite is true. The addition of the tag axle gives you greater cargo capacity so you’ll be hard pressed to overload the rear axles on a tag axle coach. But the tag axle also acts as a fulcrum, shifting more weight to the front steer axle, which can cause it to exceed its GAWR. When looking to buy a tag axle coach, pay close attention to the GAWR on the front axle.,


    A typical placard, this one from a 2007 Allegro Bus, showing GVWR, GCWR, CCC and SCWR.

    RV Hitch Rating

    Your trailer hitch should be stamped with a pair of ratings, although you might have crawl under the hitch to find it. The first is the tongue weight and the second is the rating of how much you can pull. Tongue weights aren’t a problem if you are flat towing with a towbar because the towbar merely acts as a connector between the two vehicles and the only weight that is applied to the motorhome is part of the weight of just the towbar. If you have a trailer you will need to check  the tongue weight of that trailer when loaded to ensure that it doesn’t exceed what is stamped on the hitch. You may have to shift some of the trailer’s cargo rearward if excessive. If you utilize a hitch mounted carrier for a motorcycle lift, you’ll also need to ensure that your hitch is rated to carry that additional weight.

    Gross Combined Weight Rating (GCWR)

    The Gross Combined Weight Rating, or GCWR, is the total weight of the combination of motorhome and anything it is towing. The GCWR will exceed the GVWR by anywhere from 3,000 to 10,000 lbs. It’s not strictly an indication of how much you can tow but it is designed to prevent damage to the engine and its cooling system, the transmission and other components. If you are loaded up to the full GVWR when traveling, the difference between the GCWR and GVWR will be your maximum towing ability. If you are traveling at less than your GVWR, you can add those additional pounds to your towing rating. However, your ability to tow is limited by two factors.

    First of all, the motorhome’s trailer hitch has a rating which you cannot exceed – so your towing capacity will be the least of either the hitch rating or the difference between the GCWR and GVWR. It’s like a chain where the weakest length determines how much the chain can lift. You may have a 5,000 lb. hitch with an 8,000 lb. GCWR/GVWR delta so you’ll be limited to 5,000 lbs. because the trailer hitch is the weakest point. Conversely, you may have a heavy-duty 20,000 lb. hitch on that vehicle, but you’ll still be limited to the 8,000 lb. delta between the GCWR and GVWR

    Lastly, the GCWR is based upon having trailer brakes on your trailer. The brakes on the motorhome are not designed to safely bring your coach to a stop in the required distance when towing. Most RV owners prefer to tow four down with a tow bar so you will need to use a supplemental braking system with your towed vehicle.

    Maximum Inflation Pressure (MIP)

    Your tires have a Maximum Inflation Pressure, or MIP. The sidewall of the tire will designate the maximum inflation pressure as well how many pounds that tire is capable of supporting. Again, this is why it’s important to have your coach weighed on a four corner or per axle basis when fully loaded. Your tire manufacturer will have an inflation table for each specific size or  tire that they make. This chart will tell you what the cold inflation pressure, or CIP, should be  for that weight rating.

    Once you have your coach weighed you can determine how much pressure is needed in your tires. If the tire is designed for more weight than what you will be carrying you don’t have to inflate it to the maximum inflation pressure. Reducing the pressure will give you a better ride and improve traction. It’s always good to run about 5 psi over what the chart states though to allow for any changes in the future. It also allows for a slight weight imbalance between the left and right tires. You must always use the same pressure on both tires on the same axle though, but you can have different pressures between the steer and drive axles. Always keep a minimum pressure of 85 PSI on large drive or tag axles tires to ensure the tire’s bead stays seated on the wheel rim.

    By ensuring that all of these ratings are not exceeded you’ll be sure that you can safely operate your motorhome. Following is a list of links to inflation charts for RV tires from some of the major manufacturers:

    National Indoor RV Centers blogger Mark Quasius profile picture

    Mark Quasius is the founder of, the past Midwest editor of RV Magazine, writes for numerous RV-related publications and a regular Contributor to FMCA’s Family RVing Magazine. Mark and his wife Leann travel in their 2016 Entegra Cornerstone.

    RV Sanitation Systems

    Understanding your RV sanitation systems can prevent some foul problems

    Motorhomes are self-contained with a fresh water system as well as holding tanks to handle waste water from the various plumbing fixtures. While dealing with waste water isn’t the most glamorous part of owning a motorhome, it is nonetheless an important part. Unlike a residential plumbing system like in your home, an RV has a number of things that have to be kept in mind and taken care of or else you’ll be in for a few messy and smelly problems. Fortunately, it’s not that bad if you understand how things work and pick up a few tips to help keep them working as it should. Let’s first look at how an RV’s waste water system is constructed.

    Your RV Has Two Water Systems – Not One

    To begin with, there are really two systems, not just one. The gray water system handles the waste water from the sink drains, shower drain and dishwasher, if equipped. The black water system handles the waste from the toilets. This method provides for two separate holding tanks, one to hold the black water and one to hold the gray. The reasoning behind this began in the early days of RV use. Drainage from sinks and showers contributed more volume than waste water from the toilets and needed to be drained more frequently. In addition, the gray water was relatively clean and could oftentimes be allowed to drain onto the ground, although many locations no longer allow that due to local public health laws. On the other hand, the black water wasn’t very sanitary and needed to be disposed of in a proper dump station or sewer connection. Having the two separate tanks made it possible to have multiple dump cycles rather than dumping all the waste at the same time. Another benefit to the two-tank system is that the gray water tank is relatively clean because it’s mostly soapy water while the human waste and toilet paper found in the black tank can cake up inside the tank walls, causing tank level sensors to foul and give errant readings.

    The vast majority of motorhomes have a single sewer connection used to connect the sewer hose to the holding tanks. A pair of dump valves, one for each holding tank, connects via a wye connector to this common outlet. These valves are blade type valves to prevent clogging and can be either manually operated or electrically operated with a remote switch.


    A set of remote electric dump valve switches in our Entegra Coach.

    Each tank is connected to a vent stack that extends out of the roof to eliminate a vacuum from forming in the tank when draining and expansion as the tank is being used. It also allows for odors to vent from the tank. You may have a pair of vent stacks for the two holding tanks, or they may be tee’d together into one common vent stack. A hood is applied to the vent stack to prevent rainwater or debris from entering the tanks via the vent stack. These hoods can be simple rain caps or venturi style fittings that allow the wind to help ventilate the tanks.


    Rooftop vents, such as this 360 Siphon, are required to ventilate the holding tanks and provide makeup air when draining the tanks.


    Of course, you’d never know when you have to dump your holding tanks without some kind of indicator. Early tank designs used three sensor probes that were inserted into the tank. One was located at the one-third level, another at the two-thirds level and one at the very top of the tank. These sensors were inserted through the sidewall of the tank and would conduct electricity when wet. A wiring harness connected them to a monitor panel inside the coach to display the tank levels. If the tank was full, all four LEDs would illuminate. If the fluid level in the tank reached the two-thirds level, only three LEDs would light up. At one-third, only two would light up and if below one-third, only the bottom “empty” LED would be lit.

    This system worked for years but had a few drawbacks. For one, the sensors easily fouled and gave false readings, so it was imperative to keep the tanks as clean as possible. Another concern was their accuracy. If the tank level was just below the two-thirds sensor, it would register one-third full on the display. You might think you have plenty of room left in the tank but all you had to do was add a little bit of water to the tank and it instantly jumped to two-thirds full, so you never really knew exactly how full the tank was.

    The next big improvement was the SeeLevel tank measurement system. This system used external sensors that used adhesive to attach to the outside of the tank. These sensors were full length and used radio waves to determine the precise level of the tank’s contents.


    The SeeLevel system uses digital sensors that are externally mounted to the tank and displays the levels in 2% increments on a digital display within the coach.

    A second SeeLevel display panel can be mounted in the wet bay to monitor tank levels when draining or filling the tanks.

    In addition, the external mount prevented the sensor from fouling. The only time an errant reading was displayed was if the inside tank wall was seriously caked up and needed a major cleaning. The display panel inside the coach was a digital display that reported in actual percentages, usually with 2-4% accuracy. The displays were available in multiple configurations that could cover the LP tank level if needed as well as switches for water pumps. Multiple displays meant you could have one display inside the coach with a second display in the wet bay. Eventually this sensor technology also found its way into the multiplex wiring systems, such as Firefly’s VegaTouch system, so that it could be displayed on their central touch screen panel.


    Typical basement wet bay from my Allegro Bus, showing water filter, hose reel, dump valves, water pump and all valves and controls.

    RV Toilets

    While sinks, showers, dishwashers and laundry centers aren’t that much different than what you would find in a sticks and bricks home, the toilets used in an RV are markedly different. A residential toilet has a large water closet that acts as a storage tank for clean flush water. It also has a trap that fills with water to prevent any sewer gas from backing up into the home. When you press the flush lever the tank water runs into the bowel with a vengeance, rinsing the bowl and using gravity to flush the water down into the sewer. The tank then refills with water to be ready for the next flush. An RV needs to conserve water because both the freshwater and holding tanks are limited in size, so a different design is used. In most cases an RV toilet consists of a blade valve that is kept closed except when flushing. These gravity dump toilets are placed directly over the black water holding tank. The blade valve is either operated manually via a foot pedal or electrically via a wall mounted switch. When you activate the flush mechanism, the blade valve opens to allow the waste to fall into the tank below and a measured amount of flush water is expelled to rinses the bowl and provide some water to the holding tank to prevent the waste from drying out.


    If the dump valve blades get sticky a drain valve lubricant can be added to the tank to help free it up.

    In some cases, it’s not possible to locate the toilet directly over the black tank. This is especially true when your coach has a 1.5 bath floorplan with one toilet midship and another in the rear bath. In that case, a macerator toilet is used. A macerator toilet uses a motorized grinder to grind the waste up and pump it to the black tank regardless of where the tank is located. Instead of a blade valve, this style does use a small trap filled with water. When you push the flush button, the bowl fills with more water and then the macerator kicks in and pumps the waste through a smaller 1-1/4” line to the black holding tank. Then it adds some more water to the bowl. Macerators are necessary when the black tank isn’t located beneath the toilet. The only real disadvantage to them, other than cost, is that they do use more water when flushing than a direct gravity dump toilet, which can be a concern when boondocking with a limited water supply. However, the extra water used helps to keep the solids in the black tank suspended and will keep the tank walls cleaner.


    Macerators use a smaller diameter 1-1/4 to 1-1/2” hose and can pump the waste uphill and for longer distances than a gravity dump 3” sewer connection.

    RV Sewer Hoses and Fittings

    You need to have a way to transfer the waste from the tanks to a sewer connection or dump station so that requires a sewer hose. Sewer hoses use a common 3” inside diameter hose with an industry standard bayonet connection. These “slinky” hoses are typically vinyl with a spiral wire reinforcement to prevent the hose from collapsing and come in various grades. The cheapest hoses are very thin and won’t last very long. You will develop pinhole leaks, cracks and tears quickly. Upgrading to a heavier vinyl helps but even with the extra heavy-duty hoses, you’ll still have issues. Many motorhome owners have gone with Camco’s Rhino Flex hoses, which are a step up over traditional vinyl hoses. These hoses can hold their shape more easily and are quite a bit stronger. My personal choice is Valterra’s Viper sewer hose. The Viper hose is unique in that it doesn’t uses any helical wire in the hose. The spiral wire used in typical sewer hoses keeps the hose from collapsing but it also leaves a corrugated interior to the hose, which provides restriction when dumping and lots of crannies for waste sediment to pack up inside the hose. This requires additional water to rinse the hose clean. The Viper hose has no wire and the interior is smooth so it rinses clean. You can also step on it to crush it flat and it will bounce right back, unlike a corrugated wire hose which will remain flat and kinked. It also remains flexible at down to -20 degrees Fahrenheit, so it really blows all of the other hoses away.


    Sewer hoses, such as this Valterra Viper are available in kits or as individual components.

    A Viper 10’ extension hose.

    The Viper hose has the ability to be crushed, yet return to its original shape.

    Sewer hoses have a male and female bayonet connector so you can connect multiple hoses together if you need additional length. They typically are available in either 10’ or 20’ lengths. I prefer to use 10’ lengths because I can always use two to get to 20’ if I need the extra reach. Plus, I keep a third hose on hand in case I ever have a failure. Various fittings are available to connect to a sewer connection. A campground sewer connection may be as simple as a bare pipe sticking out of the ground or it can be a PVC pipe with either 3” or 4” pipe threads. The most common connector for any RV is a 90-degree elbow with a female bayonet connector to connect to your sewer hose and a long snout to insert into the sewer. Most have a slide-on threaded adaptor that is molded onto the snout. This adaptor has both 3” and 4” male pipe thread so that it can fit either size sewer pipe. If you find you are at a site with a bare unthreaded pipe, you can slide a rubber or silicone donut over the pipe. This will allow you to press the elbow into the unthreaded pipe when necessary. It’s also typically used at a dump station, where the sewer pipe is generally just a hole in the concrete pad. These elbows can also be found in clear plastic so that you can monitor the color of your waste. This is helpful when you are rinsing your black tank and want to know when it is clean. Clear pipes that can be inserted in line with the hose are also available.


    A threaded sewer elbow in clear plastic allows you to see when the tank flushing process has been thoroughly cleaned.

    90 degree sewer elbows are threaded for various size pipe threads and also a long snout to accept a donut for unthreaded sewer connections.

    Sewer hoses do have limited use because they use gravity to dump. If your motorhome’s sewer connection is fairly low and the campground sewer sticks out of the ground quite a bit, gravity isn’t going to work very well for you on this uphill battle. If it’s not too serious, you can just walk the hose from the coach to the sewer after dumping to drain the fluid resting in the hose manually.


    Macerators grind up waste and can be portable or mounted in the coach, as in this Entegra.

    Macerators use a smaller diameter 1-1/4 to 1-1/2” hose and can pump the waste uphill and for longer distances than a gravity dump 3” sewer connection.

    Another option is a macerator. A macerator uses a motor to grind the waste and pump it uphill, similar to a macerator toilet. While a 3” slinky hose has a limited length and cannot go uphill, a macerator uses 1-1/4” or 1-1/2” hose that can pump uphill up to 9’ vertically and 100’ horizontally. Some of these models, such as the SaniCon Turbo, are installed permanently in the RV and feature a 3” bypass port for a slinky. Other models are portable and will connect to the coach’s bayonet fitting on the dump valve wye. They are a bit slower to dump that a 3” slinky but offer the ability to overcome gravity when dumping your tanks.


    Dump valves come in 3” and 1-1/2” sizes and are easy to replace. Replacement seal kits are also available.

    Operation and Cleaning

    Your gray water tank isn’t very fussy. As long as you scrape the heavy stuff off your dishes before washing them and keep from pouring oils and fats down the drain, your gray tank will remain pretty clean. The soapy shower water and dishwater help keep the inside of the gray water tank clean so that your sensors won’t give you any trouble. But your black water tank is a bit pickier, so you’ll need to pay attention to it to prevent any issues from appearing. The biggest problem with black tanks is that the waste can dry and cake up on the inside of the tank walls. This leads to unreliable sensor readings. The most important thing is to keep the waste fluid and don’t let it dry out. Saving water can be a disadvantage in that respect.

    It’s possible to use a gravity dump toilet with very little water usage. When the toilet’s blade valve opens, the solid waste and toilet paper can just fall through the gate and lay in a lump beneath if the tank is low on water. With continued use, this “pyramid of death” builds and you’ll need a construction crew to break it up. Avoid this by using plenty of water when you flush the toilet. When you dump the black tank, be sure to add plenty of water to the tank so that you aren’t starting out with a dry tank. This water will help to keep future waste additions soluble. Some users like to keep their gray tank dump valve open, but this can lead to a tank with dry sediment caked in it over time. It also allows for certain insects to leave the sewer and enter the coach – you may wind up sharing a shower with them.

    Many black tanks will have a flush mechanism installed. This is basically a spray head that sprays water around inside the tank. In some cases, this sprayer can rinse down any accumulated waste that is caked on the tank walls. In other cases, it’s limited to merely pushing any loose sediment on the floor of the tank to the dump valve. Frequent use of the sprayer whenever dumping the black tank is recommended. If you wait too long, the waste will cake up on the walls and be much harder to remove. If you find that this is the case, it’s best to mix up a solution of Pine Sol and fill the tank to about ¾ full, then drive to your next destination. The sloshing action while driving will help rinse the tank walls and put everything into suspension. Then dump immediately after arriving at your destination and finish off with the tank flushing attachment.


    Electric dump valves can be located in hard to access areas, like this Entegra Coach, and can be remotely operated.

    Never leave the black tank dump valve open when camping or you’ll experience severe caking and bad sensor readings. Always keep the valve closed unless dumping. It’s a best practice to always dump your gray tank after the black tank. The onrushing flow of soapy gray tank water will help flush any black tank residue from your sewer hose.

    If you dump the black tank too often, you’ll never get the water level high enough to prevent waste from caking on the upper portion of the tank walls. Be sure to get the fluid level up high enough before dumping. Ideally, you can do this after a day’s drive to derive the benefit of the sloshing that has taken place. Also be sure to only put human waste and approved toilet paper into the black tank. Never put facial tissue or feminine products down the toilet. You don’t have to buy expensive “official” RV toilet paper from an RV dealer or camping supply store. You just need to use a septic safe paper that will dissolve and break up in water.

    You can test your choice of paper by doing the Mason jar test. Place a wad of toilet paper into a Mason jar and fill it about ¾ full of water. Screw on the lid and shake it for about 15 seconds. The wad of paper should now be dissolved into a bunch of fluff suspended in the water. If it is – you pass the test and it’s RV safe. If it’s still a wad of paper and hasn’t broken down – don’t use it in the RV because it will plug up the system.

    Chemicals and UViaLite

    This brings us to chemicals. A common misconception is that you need to add RV-specific chemicals to treat your waste tank. This is not quite true. Both human waste and toilet paper will dissolve in plain water. You don’t need tank treatment chemicals to do that. If you neglect your black tank, you may need some heavy-duty tank chemicals or Pine Sol to clean it but under normal use, you won’t. One thing chemicals do is deal with odors – although that’s not all it’s cracked up to be either.

    Some chemicals are nothing more than perfume. They don’t remove the odors, but they mask it by adding a more favorable scent to the tank. Other chemicals include enzymes that do react with the odors, but enzymes are organic organisms that take 5-7 days to become active. Most RV owners don’t wait that long to dump their tank, so they are basically flushing away good money every time they dump.


    Liquid waste digester, such as this Pure Power Blue, will help treat solid waste to prevent clogs and prevent odors.

    A great system that I am familiar with is the UViaLite system. I first noticed this system when reviewing an American Coach for a magazine article I wrote for another publication. I also noticed this system on a Thor diesel coach on another article and have since learned that other manufacturers are looking at implementing this system.


    This particular bay on an American Coach shows the UViaLite waste tank ventilation system installed.

    UViaLite uses proven technology that uses an ultraviolet light set to a specific frequency of 185 nanometers to react with oxygen (O2) to create ozone (O3). This unit picks up fresh air from beneath the coach and passes it through the UV module and into the top of the tank via a 1-1/4” PVC pipe. There are no moving parts because the system uses the chimney effect of natural airflow rising through the tank’s vent stack. 6 to 20 PPM of ozone are created in the unit and the thermal updraft of the vent stack draws the ozone into the holding tank at less than 1 CFM. Once powered up, the unit can remain on and only draws 0.8 amps of 12 VDC power, which is around 10 watts. The unit can remain on until the user stores the RV at the end of the travel season.


    This image shows how the UV light creates O3 from O2

    Shows how Ozone attacks viruses and bacteria to form oxygen, carbon dioxide and water vapor.

    Shows how odors are eliminated by converting the smelly hydrogen disulphide to water and sulfur that settle in the water and oxygen which vents out the stack.

    Ozone is a powerful oxidizer that will kill bacteria and chemically destroy viruses in seconds. The ozone generated by the eco-friendly UViaLite attacks the molecular bonds of viruses, bacteria & mold, breaking them up into harmless water vapor and carbon dioxide (CO2). UViaLite removes the stinky smell caused by hydrogen disulfide in the tank by converting it to freshwater vapor and sulfur that falls out of the air and into the tank.


    This diagram shows how the air flows through a UViaLite system.

    Eliminating odors rather than masking them with a perfumed scent will make a big difference whenever someone flushes the toilet, especially when the bathroom exhaust fan is on. Because it also kills any pathogens, it will prevent viruses shed from a sick person from wafting up out of the tank and possibly infecting other people in and around the coach. UViaLite does not affect anything in the liquid portion of the tank so it won’t affect any chemicals you may have in there. It only affects the air above the liquid, which is where the odor is anyway.

    Keep in mind these few tips and you’ll qualify as an RV sanitation expert in no time!

    National Indoor RV Centers blogger Mark Quasius profile picture

    Mark Quasius is the founder of, the past Midwest editor of RV Magazine, writes for numerous RV-related publications and a regular Contributor to FMCA’s Family RVing Magazine. Mark and his wife Leann travel in their 2016 Entegra Cornerstone.

    RV Electrical System Failure

    RV Electrical System Failure

    Sometimes these systems can fail, not that this will come as a shock to anyone. When electrical systems fail it’s time to do some testing to see where the failure is. A voltmeter is a huge help in this area although a test light can also be used to test low voltage circuits. Personally, if you are a motorhome owner you should have a multi-meter of some sort. It’s invaluable for checking high voltage circuits, campground pedestals, low voltage circuits, and continuity.

    Fuse Panel

    Fuse panels hold fuses for all 12-volt systems

    Check for Blown Fuses 

    The first thing to do is to check for blown fuses. Sometimes you can do this by removing the fuse and holding it up to the light to determine if the fusible link is blown. Sometimes it’s not so easy to see. The way many of these fuse panels are labeled, or more accurately, “not” labeled, you may have trouble figuring out which fuse does what. The common ATO fuses are blade type fuses with a plastic housing. There are bare spots on the end of the housing that can be used to test for voltage. If you have power going into the fuse, but not out of it, you’ll know you have a bad fuse. Another method is to use the ohms setting on a multimeter. Remove the fuse and check for continuity with the meter. If there is no continuity, the fuse is bad. If you have a critical circuit you can also replace those fuses with ATO style circuit breakers that plug right into place. There are also fuses with LED pilot lights that will illuminate if the fuse is blown. So, you have lots of options when it comes to fuses.


    Test for Voltage 

    If it’s not a fuse, then you need to look a little deeper. If the fuse does have power leaving it, test for voltage at the device that isn’t working. If you have power coming into the device, it’s either a bad device (light bulb, fan motor, water pump, etc.) or else you do not have a complete circuit. In that case, I’d check for a bad ground because an open ground won’t provide a complete circuit back to the battery. If you do not have power at the device, there is an open circuit between the fuse and the device. The first place to look would be at the switch. Test to see if there is power coming into the switch and power exiting the switch. If the power is getting to the switch but not leaving it, it’s time to replace the switch.

    Wire Gauge (AWG) Wire Diameter, in Inches Current Capacity, in Amps
    0000 .4600 600
    000 .4096 500
    00 .3648 400
    0 .3249 320
    1 .2893 250
    2 .2576 200
    4 .2043 125
    5 .1819 100
    6 .1620 65-80
    8 .1285 40-50
    10 .1019 30-33
    12 .0808 20-23
    14 .0641 15-17
    16 .0508 7.5-10
    18 .0403 5
    20 .0320 3.3
    24 .0201 1.3
    28 .0126 0.5

    This chart shows the current capacity for various wire gauge sizes

    3 Advantages to Financing Your RV

    Just like it matters where you buy your RV, how you finance it matters too! 

    Picking the perfect RV is no easy task. Across every brand and RV class, some seriously great options are available. From Newmar‘s massive Class A King Aire RVs to the comparatively humble Class B Winnebagos, there’s something for everyone.

    Once you’ve picked the perfect RV, you’ve still got one more big choice ahead of you: how to pay for it. While RV newcomers often assume the process is similar to buying a car, reality can be much more complex—especially if you’re choosing a high-end model. 

    Given how big of an investment an RV can be, many drivers are tempted to either pay cash out of their savings or secure a line of credit from their bank, which allows them to cover most (if not all) the cost of a new motorhome. However, this isn’t always the best route to take.

    Working with your RV dealership’s financing options can have some serious advantages, both in the amount of money you owe and the terms you get for repaying it. Let’s take a look!

    Financing an RV Offers More Flexibility in Repayment Terms

    As RVs can be individually expensive purchases, they come with many considerations when navigating repayment terms. It’s not unheard of for the loans on some luxury RVs (Class A vehicles especially) to extend over 20 years or 240+ months. That means these loans have more in common with a second mortgage instead of a car loan.

    It’s hard to imagine your local bank or credit union offering terms like these. Many likely aren’t familiar with the intricacies of owning an RV, and this can create a whole host of headaches.

    Discussing financing options with your RV dealership can also save you the steps of dealing with a pre-approval process, which can translate to serious time savings. Depending on where you would otherwise source your RV financing, it’s easy to miss an entire season dealing with clerical tasks. By contrast, an RV dealership understands how important it is to get you behind the wheel of your new RV as soon as possible.

    Financing Also Offers Lower Average Monthly Payments

    Working with your RV dealership to figure out financing options doesn’t just translate to more flexibility in your repayment timeline; it can also easily translate to lower monthly payments. As we mentioned above, some RV loans can last more than a decade, which translates to very different considerations versus a regular car loan.

    More often than not, these longer RV loans translate to significantly lower monthly payments, sometimes as low as $200! Renting an RV for that much money is considered a steal, so try to wrap your mind around owning one for that amount. 

    Even better, drivers can expect to pay a lower average down payment as well. As there are fewer hoops to jump through when you reach out directly to your RV dealer, you can expect a cleaner (and more affordable) close on your new motorhome!

    An RV Dealership Will Be Uniquely Qualified to Work With You

    If you’re noticing a theme here, it’s that RV dealerships are better equipped to work with the unique needs, costs, and considerations of owning an RV than virtually any other source of financing. 

    There’s a really obvious reason for this: RV dealerships know more (and care more) about RVs than other sources of financing!

    Beyond perks like lower down payments and more flexibility in choosing a repayment window, you can rest assured your servicer actually understands the intricacies of owning an RV! (That’s not something you can always say for banks and credit unions.) This understanding translates to a better all-around experience. After all, your RV dealership’s goal is to sell you an RV, which means they’re strongly incentivized for finding the best possible financing options for you. 

    Our financing office works with drivers to find the best possible options for their unique circumstances. Learn more about the different financing options available at NIRVC.

    Living Full-Time In An RV

    What Is It Like Living in an RV?

    Life looks different on the road. There are plenty of immediate, obvious ways that living in an RV is different from living in a fixed home, but some of the biggest differences can be hard to appreciate until you’re actually behind the wheel. Here are some of the most significant ways that life changes when living in a motorhome: 

    Your Pace of Life Slows Down – and That Can Be a Good Thing

    RV life operates at a fundamentally different pace than life elsewhere. The best parts of RVing are often found when exploring new places or unusual locales. That’s difficult to do if you’re constantly in “go” mode. Over time, you’ll naturally adapt to a pace that lets you savor your surroundings, which can look pretty different from the hustle and bustle of digital life. 

    This naturally comes with a change in how you perceive the world. Instead of frantically counting down the days until Friday, you begin to view each week as a chapter in a larger, ongoing journey. In time, you come to appreciate special events even more because you view them as magical moments in time, not hours in a schedule.

    Traveling Means You Get Diverse Experiences From Unexpected Places

    RV camping lets you see parts of the country that are easy to miss if you only travel by air. Every state is full of interesting detours, quirky towns and beautiful sights that are best appreciated from the road. 

    One of the most liberating aspects of RV travel is that it’s (hopefully) not subject to the same schedule crunch as trains and planes, meaning that you’re free to take your time if a place catches your interest. Veteran RVers will tell you that some of their best adventures come from unexpected places, and living behind the wheel of a motorhome makes you equipped to appreciate them when you find them.

    You Meet New Friends – and Plenty of Interesting Locals

    While not every person you meet at a campground is going to land in the “birthdays and baptisms” part of your life, you’re bound to make plenty of friends. RVers are a famously friendly crowd, meaning that you’re sure to find good company at almost any campsite that you visit. Over time, you may even start to notice some familiar faces at the different places that you frequent! Social media and RVer groups like AIM Club make it easier than ever to connect with like-minded individuals while attending exciting rallies, outdoor excursions, RV training courses and other fun RV-focused experiences. 

    New friendships aren’t always limited to other RVers either. During your travels, you’ll undoubtedly meet plenty of locals, and that provides plenty of opportunities for making new friends! 

    You Get a New Appreciation for (and New Definition of) Safety

    When your home is on wheels, you quickly learn to appreciate all of the care that keeps it running. You also develop a strong sensitivity to potential safety hazards, and that means thinking about it in a way that suburbanites and city dwellers don’t. As an RV owner, any issues in your vehicle translate to issues with your house, and visa-versa. 

    Most home and apartment owners merely have smoke alarms and fire extinguishers to fight fire, but RV drivers will happily opt for something more advanced. A leading example of this is THIA by Proteng, a patent-pending fire suppression system that is heat-activated, minimizing fire damage by eliminating heat at the source. 

    Ultimately, It’s About the Little Things

    Living in a motorhome allows you to appreciate life from an angle that’s difficult to find anywhere else in the modern world. While you’ll be sacrificing some areas–a fixed routine or consistent access to sushi–you’ll be gaining in just as many others. One of the biggest changes that happens is a newfound appreciation for the little things. 

    While an RV trip is ultimately about getting somewhere (like the East Coast or the Grand Canyon), the little moments that happen along the way are often what make it magical: Unexpectedly good food from a local dive; nights spent stargazing free from the light pollution of the city; grilling away the afternoons with newfound friends at a shady autumnal campsite. These small adventures are what make RV life worth it and you’ll come to develop a profound appreciation for them. 

    RV life is ultimately about adventure, and there’s no shortage of it to be found on the open road. Sometimes these adventures are big cross-country endeavors, and sometimes they’re as simple as an afternoon of fishing. Either way, living behind the wheel of a motorhome puts you in a unique position to experience – and appreciate – all of the magic that our big, beautiful country has to offer.

    If you’re ready to take the next step and learn more about RV living, contact one of our Lifestyle Specialists today!

    RV Generator Selection

    RV Generators: A How-To Guide

    Modern motorhomes are packed with the latest technology and household conveniences. Items such as washer/dryer laundry centers, dishwashers, entertainment systems featuring multiple HD TVs, residential refrigerators and electric cooktops all require 120 volt AC power – and that’s in addition to the rooftop air conditioners. 

    All of these items operate just fine when you are parked and plugged into a campground pedestal that supplies shore power to the coach, but what happens when you are driving or camping at a location that does not have any shore power? 

    Many coaches have inverters that will power some devices, such as a residential refrigerator, microwave oven and entertainment systems. But larger AC power loads can’t be handled by an inverter when driving, such as rooftop air conditioners. Plus, dry camping inverters can draw down your battery bank pretty quickly, so you will need to rely on the motorhome’s generator to provide AC power in order to operate these items and to recharge your battery bank.

    Generators come in various forms and sizes, so it’s best to analyze what your power consumption needs and particular applications are when choosing the best generator for you. First, let’s understand a bit how generators work…

    Portable- Versus Permanently-Mounted RV Generators

    Most larger Class A coaches will come equipped with a generator that is permanently installed in the coach. Larger diesel pushers generally have them installed in the nose of the coach and are mounted on a slide-out rail for ease of service. Gasoline powered motorhomes that are of a front engine design will have them installed in a side compartment, or may even be an optional feature.

    National Indoor RV Centers blog RV Generator in Class A motorhome

    Generators such as this 5500 watt Onan Marquis Gold gasoline powered generator are commonly mounted in a basement compartment on gas powered class A motorhomes.

    Installed generators have the benefit of using the same fuel tank that feeds the engine. The output wiring is connected to an automatic transfer switch, making it a simple task to start the generator via a switch in the motorhome’s interior. Smaller Class C and Class B motorhomes are limited on storage, so a generator is often an option not chosen by the buyer, opting instead for more storage space. In that case, a portable generator might be a better choice.

    National Indoor RV Centers blog-RV-compact-generators-Class C-Class B motorhomes

    Compact units – such as this 4,000 watt gasoline powered Onan – are typically installed in Class C or B+ coaches where basement cargo space is limited in height.

    Portable generators won’t tie up your RV’s basement storage space, but you will have to find some place to carry it, like in the back of a pickup bed. They can multitask, so you can use the generator in other locations without the RV. You can even use it to provide emergency power during an outage at your home. One drawback is that you need to carry a separate fuel supply for the generator, which also requires storage. Weight is also a consideration because the need for horsepower increases as the wattage demand goes up. More horsepower means larger engines that are heavier, making the generator harder to handle.

    National Indoor RV Centers-blog-RV generators-portable generator for motorhome use

    Units such as this Honda 5,000 watt are portable and can be moved by two persons.


     Household power in North America is 60 Hertz – which is the measurement of the power’s frequency or wavelength per second – while electrical power in Europe is 50 Hz. Any electrical device designed for use in North America will require 60 Hz power in order to operate. Frequency in a generator is determined by the number of times a magnetic field passes by a generator’s stator winding and receives an induced charge. In a generator with two field coils, the generator needs to spin at a constant 3,600 RPM in order to create 60 Hz power while a generator with four field coils only needs to run at 1,800 RPM.

    Most portable generators are of the two pole design to save weight on both the engine and the generator itself. For example – a 3,500 watt generator will require around 8 HP to generate that much electrical power. A typical 8 HP engine will produce that power at peak RPM, which is going to be close to the 3,600 RPM that a two pole generator will operate at. A four pole generator will only need to turn at 1,800 RPM to achieve 60 Hz, but a four pole generator is heavier and bulkier and the engine won’t be able to create its maximum rated power at that slower speed. Therefore, a large engine rated in the 12-14 HP range at 3,600 RPM will need to be used so that 8 HP is still available at the lower 1,800 RPM. The extra weight and size of the larger engine and generator doesn’t make it a good choice for a portable generator but is best suited for a stationary mount where the quieter operation associated with lower RPMs is beneficial.

    Split Phase Versus In-Phase:

    Regardless of whether your generator is a two pole or four pole unit, there will be two field windings that provide power to the receptacles. Each winding is capable of producing 120 volts of AC power at one half of the rated capacity of the generator. These windings can be connected in series to offer 120 or 240 volts in a split phase design, or in parallel to offer only 120 volts in what is referred to as an in-phase design. For example – a 6,000 watt generator has two field coils, each with 3,000 watts of available power at 120 volts. Referring to the graphic below, we can see that there are 6,000 watts of 240 volt power available between L1 and L2. There are 3,000 watts of 120 volt power available between L1 and Neutral, and another 3,000 available between L2 and neutral. 3,000 watts at 120 volts is only 25 amps. Unfortunately, you can’t draw 30 amps on one circuit because the two fields are in series.

    National Indoor RV Centers blog RV Generators split phase wiring

    The graphic referred to in the text as the Split Phase diagram

    The split phase system works fine on larger generators, such as 10,000 watts and up, but has its limitations on smaller units. Many of the smaller units used in RVs do not have 240 volt capabilities, which is fine because 240 volt appliances in an RV are extremely rare except for very high end coaches. In this case, the two windings are placed in parallel rather than series. This eliminates any 240 volt capability but allows for the full 6,000 watts to be available on any one circuit. This is referred to as an in-phase system and is generally used on generators rated at 7,000 watts or less. 

    Inverter Generators

    Inverters are the opposite of converters. A converter takes 120 volt AC power and converts it to 12 volt DC power to operate lights, water pumps, fans and other 12 volt accessories in the RV as well as battery charging power. An inverter takes 12 volt DC power from the batteries and inverts it to create 120 volt AC power. Small inverters can be used to power an entertainment system while larger inverters can power a number of receptacles and appliances. This means you don’t have to run your generator to keep a residential refrigerator cold while driving and can also operate a microwave and a few outlets. They are helpful because it extends the time interval between times when you need to run the generator to recharge batteries or run larger loads.

    National Indoor RV Centers-blog-RV generators-inverter- based-Honda 2200-unit

    An inverter based Honda 2200 watt unit.

    However, inverter technology has also filtered into generators as well. Inverter based generators are popular in some of the small portables, such as the Honda EU2200 series as well as in the Onan Quiet Diesels in the 7KW to 8KW range. In a sense, these generators are not true AC generators, although their eventual output is AC power. They are actually DC generators that send their variable DC output through inverter circuitry built into the generator itself. This eliminates the requirement to operate at a steady 1,800 or 3,600 RPM because the inverter electronics convert the DC power from the generator into 120 volt AC power and establish a 60 Hz frequency electronically. 

    A DC generator has no requirement to turn at any given speed because the output power increases as the generator’s speed increases. This allows the generator to operate at a lower RPM under light loads, saving fuel and reducing the noise level. 

    As you add more demand for power, such as when an air conditioner starts up, the generator’s speed will increase to raise the power output level, all the while maintaining a steady 120 volt AC power level at a 60 Hz frequency. Inverter based generators also put out fairly clean power with low levels of noise or total harmonic distortion (THD), which is a benefit when powering sensitive electronic equipment. Inverter generators are not found in the larger 10KW  sizes and up because the inverter boards would be large and expensive and generally not necessary with the stability present in the larger diesel generators. However, they are quite popular in the smaller portable models.


    When selecting the proper size generator, it’s important to remember that wattage is the measurement of true power. A 50 amp shore power supplies 50 amps of 120 VAC power on each leg. “Amps” x “volts” = watts, so a 50 amp shore power receptacle is capable of providing 6,000 watts power on each leg, for a total of 12,000 watts. Therefore, if you want a generator that can match that power, you’ll need a 12,000 watt generator. If you don’t use all of that power, you may be able to step down to a 10,000 watt generator, but the biggest factor is with air conditioning. A coach with two rooftop air conditioners may be able to get by with a 7,000 watt generator, depending on how many other 120 volt accessories you have. But any coach with three rooftop units is going to need at least 10,000 watts.

     When sizing up a generator, you need to consider how your loads are distributed across the breaker panel. A split phase generator can only supply half of the total capacity on each leg, so you have to be sure that your heavy loads are evenly distributed across both legs of the panel. Remember that each leg has a given amount of amperage and on a split phase generator, they cannot be shared. If your loads are imbalanced, you’ll need a much larger generator just to feed one leg while the other leg is not being fully utilized. 

    Another consideration is static versus dynamic loads. Lighting and heating elements are static loads in that they always consume the same amount of amps. Dynamic loads are associated with components that have load requirements that vary under different conditions.

    Motors are considered dynamic loads because the current draw varies according to how hard they are working – plus, they generally have a startup surge which can be up to three times the running load. Consider the case of an air conditioner. It may have a typical unloaded draw of less than 10 amps, but when it first starts up it will have a surge of in excess of 20 amps as the capacitor start motor starts up against the head pressure in the refrigerant. If the unit was resting long enough, it may settle in to around 10 amps immediately after startup but as the head pressure increases and the unit works hard, it can draw 12-14 amps. Consider that you most likely won’t be starting all three air conditioners at the same time so you don’t need to use the peak starting surge for every unit when calculating how large your generator needs to be. Remember that “volts” x “amps” = watts, so just multiply your amps by 120 to convert to watts in order to determine how many watts you’ll need. 

    Following are some examples of typical load requirements:

    Air Conditioners 1400-2000 watts
    Refrigerator 600-1000 watts
    Electric Frying Pan 1000-1500 watts
    Electric Stove Element 675-1000 watts
    Electric Water Heater 1250 watts
    Hair Dryer 500-1500 watts
    CRT Television 200-600 watts
    LED Television 100-375 watts
    Portable Ceramic Heater 750-1500 watts
    Toaster 1000 watts
    Satellite Dish and Receiver 200 watts
    Battery Charger/Converter 750-1400 watts

    When sizing your generator, you also need to consider the fact that altitude affects the engine’s ability to create power. Different engines react in varying amounts. An Onan Marquis Gold series of gasoline powered generators will lose 3.5% of power for every 1,000-foot gain of altitude over 3,000 feet. The Onan Quiet Power Diesel 10,000 watt will derate 3.5% for every 1,000’ over 500’ of altitude and it further derates by 1% for every 10oF of temperature increase over 85oF. This equates to a 7,500 watt generator running at 9,000’ of altitude that will only be capable of handling 5,000 watts at that altitude unless the engine has enough excess horsepower to allow for it.

    National Indoor RV Centers-blog-RV generators-diesel generator

    Most Class A diesel pushers have diesel powered generators, such as this Onan 10,000 watt installed in the front cap area of a Newmar London Aire are placed on slide-out rails for ease in service access.

    Diesel engines are pretty much capable of handling the fuel injection requirement at higher altitudes but carbureted gasoline powered engines will have issues with running rich due to lack of air. Some generators, like the Onan Marquis Gold series, have a mixture adjustment on their carburetors. You can adjust the fuel flow with a lever to lean the engine out when operating at higher altitudes. But be sure to reset it to the full rich position when you return to the flatlands or else you run the risk of burning valves by running the engine too lean.

    Armed with this information, you should be ready to select the best generator for your RV lifestyle. Be sure to include your generator when you have your RV tech perform scheduled maintenance on your motorhome. Taking care of it will ensure it will take care of you when you need it.

    How To Power Your RV

    How to Power Your RV

    Your RV’s 120 volt electrical system is fed through a central distribution panel where all of the circuit breakers are located. In order to power this panel from two different power sources we can choose one of two methods. The first is the more cost effective and least costly and is commonly used in lower cost travel trailers. That method entails hard wiring a power cord to the breaker panel’s inputs. When not plugged into shore power this cord can be plugged into a generator set outlet to provide power to the RV’s electrical systems. While this method is inexpensive, it’s less convenient because you have to physically switch the plug from the shore power receptacle to the generator receptacle. The second method is to install an automatic transfer switch.

    Automatic transfer switch

    Manual vs Automatic Transfer Switches

    Manual transfer switches need to be manually switched by moving the switch lever on the box and are uncommon in a motorized RV. Automatic transfer switches commonly used in an RV will do this automatically and are logic controlled to switch under a given set of conditions. Generally automatic transfer switches will default to the generator inputs and are mechanically held. Once shore power is present the magnetic coils will pull the switch’s contact relays over to the shore power side. This is why you typically hear that clunk when the switch engages shortly after connecting to shore power. As soon as the shore power is no longer present the switch will revert back to its generator priority position.

    Generators for Your RV

    Sometimes the 120 volt devices in your motorhome need to be powered when you are not plugged into a campground pedestal, frequently referred to as shore power. When shore power is unavailable, the on-board generator set can be used to power these devices. Generators can be used in a number of situations, such as camping in remote areas where access to power is not available. A number of systems, such as lighting, water pumps and fans, are powered by your 12 volt battery. However, there will come a time when these batteries need to be recharged. The on-board generator can be used to power the coach’s battery charging system in the absence of shore power. Another use for generators is to power the rooftop air conditioners to make for a more comfortable motorhome interior in hot weather.

    Generators for Gasoline Engines

    Gasoline powered Class A motorhomes will be equipped with a generator powered by a gasoline engine. The generator shares the same fuel tank as the vehicle engine but uses a separate fuel pickup within that tank. Usually these pickup tubes are cut short so that the generator will not run if the fuel level gets below a ¼ tank but this amount can vary from one manufacturer to the next. The reason for this is so that you can’t totally drain your fuel tank while dry camping. The ¼ tank remainder ensures that you will always be able to start your RV’s engine and drive to a refueling location. These generator sets are designed to slide into a basement compartment that is designed for that purpose so access to the controls and engine service points is done through the removable side cover on the generator, which also serves to contain the cooling airflow and add additional sound deadening capability.

    Onan Quiet Power diesel generator

    Generators for Diesel Engines

    Diesel powered generators can be found on motorhomes that are powered by diesel engines. Some of the entry level class A diesels are really front engine gasoline chassis with a diesel engine in place of a gasoline engine. Also, many smaller B+ and Super C motorhomes are now being made with small diesel engines. In this case the diesel powered generator will be fairly small (in the 4 KW to 7 KW range) and will be mounted in a side compartment in the same fashion as the gasoline powered generators. On a rear engine diesel pusher, the front of the coach is clear of engines and radiators. In this case you’ll find a diesel powered generator that is mounted in the front cap on a set of slide rails. The generator can be slid forward out of the coach to allow better access for servicing the unit. These units generally start at around 7,500 watts and run up to 10,000 or 12,500 watts in size. 

    Some older motorhomes used a propane powered generator that ran off the RV’s on-board LP tank. However, these are rare and less desirable because the limited capacity of the propane tank didn’t give the generator a very long running time before the LP tank was empty. Used coaches with propane powered generators are very hard to sell and their resale value reflects this.

    In-Phase vs Split-Phase Generators 

    Generators that are rated up through 8,000 watts are usually single pole 120 volt-only generators, referred to as “in-phase” generators because both windings are in the same phase. Larger generators, 10,000 watts and up are two pole split-phase 120/240 volt generators with a center tap neutral. Because motorhomes rarely have any 240 volt appliances you may think that this arrangement isn’t needed. But if you refer back to our split phase 120/240 diagram you’ll recall that each phase has a given amount of amps available. That’s what allows you to balance your load and eliminate the heavy wiring required for a 10KW generator, which would output 83.33 amps if it was an in-phase design. Note that a 50 amp electrical service is equivalent to 12,000 watts, which is the size generator required if you needed to supply a full 50 amps to your RV’s breaker panel.

    What to Consider When Choosing a Generation System 

    Small portable generators tend to be noisy because an engine running at 3,600 RPM isn’t very quiet. They were designed to be light and portable. In a motorhome this isn’t important because the generator doesn’t need to be lifted because it will be mounted into the RV. What is important is the noise level. If we add a second set of field coils to our generator, we will double the frequency to 120 Hz when running at 3,600 RPM, which isn’t good and will burn up our electrical devices. But if we take that same 4 pole generator and slow it down to 1,800 RPM we will still have 60 Hz. It’s just that we are passing twice as many magnets during the same revolution so by reducing the number of revolutions by half we will still maintain 60 Hz.

    This is the way many RV generators are set up. The 1,800 RPM speed of the engine allows for quieter operation. Because we don’t have to lift this generator we can also add a nice large muffler to it. The big drawback is that we have to use a larger engine. A small 8 HP engine is capable of creating 3,500 watts at 3,600 RPM but when you slow it down to 1,800 RPM it will only put out around 5 HP, which isn’t enough. By going with a 12-14 HP engine, we will still have 8 HP available at 1,800 RPM to then make our 3,500 watts of power. This means that the engine will be physically larger, weigh more, be quieter and more durable, and cost more than a smaller engine that is running higher revs. But the gains are well worth it in an RV application. Large utility power plants carry this even further and can use as many as 24 field coils in their generation systems so that they only have to turn 300 RPM. Less RPMs means greater life but more weight and size, while less magnets means less weight and size but greater speed and wear.