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How to Choose, Maintain, and Troubleshoot Your RV Water Heater

Note: This post may contain affiliate links. This means that at no cost to you, we may receive a small commission for made purchases.

While your RV hot water heater is superficially similar to the one in your house, there are significant differences. To understand how this component works will make life on the road less frustrating when it breaks down. Alternatively, these types of hot water heaters are very similar to those used in other recreational vehicles like boats & they often share the same parts & servicing needs.

If you’re searching for info on boating water heaters, check this out:

Marine Water Heaters Ultimate Guide: All You Need To Know For Efficient Heating Onboard

Related: Best RV Water Heaters (Tankless and Mini-Tank)

Know the Fuel Source

There are three primary varieties when it comes to the fuel that powers your RV heater.

Liquid Propane

Whether a travel trailer, camper, or motorhome, many entry-level RVs supply hot water via a liquid propane water heater. This is an old, reliable system that comes in two varieties – manual pilot light and direct spark ignition.

If the former goes out, you’ll need to strike a match to get it going again. A direct spark system is more sophisticated, operating through means of a control board that detects when it’s time to automatically engage an igniter.


Most water heaters for RVs can operate on either propane or electric. The latter comes in handy if you have the option of running on generator power or plugging directly into the supplied power of an RV park. Engage both systems if you want hot water pronto.


This last fuel source should satisfy the RV techie. It works by circulating fluid from the engine’s cooling system through the hot water heater to make things hot in a hurry. Even better, it works while you’re driving, so you’ll have hot water when you reach your destination.

Tanks vs. Tankless

The basic options you have here are a water heater with a tank or without. Yes, it’s true that tanks are old technology, but they have been around a long time for a reason. Tankless models are the new kid on the block relatively speaking. So which type is the best water heater for RVs? Here are some points to ponder.


While the water heater in your home might easily hold 40 gallons or more, most RV units are in the 6 to 10 gallon range. You know what that means, right? Yep. You’re going to run out of hot water fast if you linger in the shower, lollygag around at the sink, or maybe just make too much hot chocolate.

Like it or not, unless you customize your RV to accommodate a residential-sized heater (which is a MAJOR project), you need to learn how to be a conservationist. Atwood and Suburban are the primary manufacturers of the tank style of RV water heaters.


As in the residential market, tankless water heaters are starting to catch on with RVers. Yes, you’ll have to shell out more money up front but think about this – endless hot water on demand. There’s also the reality that a tankless heater takes up less space.

Going the tankless route is definitely something to think about while picking out your next RV. Though other companies are beginning to compete, Girard created the first tankless water heaters for the RV market back in 2009 and they are far and away the best at what they do.

Maintenance is the Secret to Hot Showers

Whether you have an electric hot water heater (see also ‘Electric Hot Water Heaters Buying Guide & Review‘) in your RV or some other type, regular maintenance is critical unless you have a preference for cold showers and sullen glances thrown in your direction from the rest of the family.

Luckily, an RV heater is a simple system, with only basic upkeep requirements. Here are the ones to pay attention to:

Anode Rod

The anode rod in your RV system works exactly the same as in a home water heater. It’s a dead simple way to slow the development of rust and corrosion inside the tank. Through the miracle of electrolysis, the anode rod draws the corrosive effects to itself.

You should check it once a year and replace if worn. A typical rod lasts about 4-5 years. A caveat – if you have a glass-lined tank, no need to worry about this. It won’t rust.

Tank Flushing

It’s a good idea to drain the water heater tank if you won’t be using it for awhile and at least once a year if it never sits still for long. Regardless of your best efforts to run a tight ship, sediment will build up inside and reduce the unit’s lifespan. For best results, use a water sprayer wand that lets you get up into all the crevices and do a thorough job.


The bypass valve is a handy little thing that diverts water from the water heater but allows it to continue to flow through the rest of the system. Putting your rig up for the winter? Engage the bypass valve because you certainly don’t need a tank full of ice sitting in there through the cold times.

Don’t forget to re-supply the flow of water to the tank when you’re ready to use it again. Heating up a water heater with no water in it is bad strategy.

Another critical element of storage, especially through the cold months, is to winterize your water pipes by filling them with antifreeze and/or wrapping them with an insulated material. Otherwise, you can expect to find all kinds of spurting leaks when you head back out on the road next spring.

Trust me, repairing water lines in your RV is not how you want to spend the first day of travel.

Simple Troubleshooting Tips

No Hot Water

Several problems of the ‘no hot water’ variety can be traced to a bypass valve left in the wrong position. If the water in the tank is hot but it’s cold at the spigot, check the valve.

The same applies if you have hot water but it gets cold quickly. This also points to a bypass valve left open, allowing incoming cold water to mix with what has already been heated. If the water is cold but you know the tank has already gone through a heating cycle, check to see that the hot water valve is not closed, preventing hot water from leaving the tank.

Another common reason for no hot water is a faulty heating element. Remember back when we mentioned how important it was to remember to reverse the bypass valve at the beginning of the season? This is why. A heating element that tries to heat air rather than water will quickly burn out. It’s a good thing they’re easy to change out and the process is similar to a home water heater.

Too Much Noise

Another issue with RV water heaters is common to its residential cousin as well – knocking, pinging, or hissing sounds. Though it sets up a terrible racket, it’s not dangerous and is generally related to water trapped beneath sediment at the bottom of the tank that pops as it’s heated. As you might suspect, time to clean the tank!

Pilot Light Won’t Ignite

For propane-fueled heaters, a pilot light that won’t stay lit can doom you to a night of cold showers. Generally, this is an easy, inexpensive fix related to a bad thermocouple. Don’t let that ten dollar word scare you. Obviously, electric and motoraid systems don’t have a pilot light to worry about.

The Bottom Line

The easiest way to avoid frustration related to your RV hot water heater is to take ten minutes and learn how it works. This should make the troubleshooting effort less frustrating.

Traditional tank systems are not complicated pieces of equipment, so you should, through regular maintenance and repairs, be able to keep it usable for up to ten years. The tankless variety, on the other hand, are more complex. For problems with it you might want to call in a professional. Happy roadtrippin’!

author avatar
Anthony Barnes
Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age


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