RV manufacturers are pretty good at replicating the features of sticks-and-bricks houses in our homes on wheels. Everything from kitchen appliances to air conditioners have been incorporated into today’s RVs. It’s safe to say that the RV water heater has become a necessity.
As RVs evolve, the water heater is one appliance that most campers have discovered they can’t live without. It gives us all the creature comforts of home as we travel across the country in our RVs. While there are obvious differences between a house water heater and an RV water heater, they aren’t too complicated, and most of them do have several things in common.
Let’s discuss everything you need to know about your RV water heater.
Types of Water Heaters
There are four distinct types of water heaters available on the RV market today. Each RV water heater has its own specific benefits and a few detriments. It’s important to look at your camping style and hot water needs before deciding on the type that’s right for you (or to help you understand the pros/cons of the model that came in your RV).
Gas RV Water Heater ()
Most gas water heaters run on propane and hold between 6 and 12 gallons of water. Propane is an economical way of heating water, making a gas water heater beneficial for camping off grid.
Electric RV Water Heater ()
An electric RV water heater is dependent upon 120V shore power (or a generator) because it uses a great deal of electricity to heat the water. If you like to boondock, you may want to stay away from an electric water heater.
Gas / Electric Hybrid Water Heater ( / )
You’ll typically find these 2-way water heaters in larger RVs like 5th wheels and Class A motorhomes. You can use the propane gas and electricity simultaneously to speed up the heating of the water, but keep in mind that in order to utilize the electric side, you’ll need shore power or a generator.
Tankless RV Water Heater ()
These heaters offer a steady stream of hot water on demand. Once started, they can produce hot water for quite a while (depending on the amount of fresh water available, of course). Because they’re not ‘storing’ water, but instead, move cold water past a heating element, they provide continuous hot water. With no storage tank, they also take up less room in the RV. Most models of tankless RV water heaters that are available today are heated only by propane, but because they only fire up when hot water is needed, they tend to use less propane than a standard gas or gas/electric model with a tank.
RV Water Heater Features
Tank Size ()
Most standard RV water heaters hold 6 to 12 gallons of hot water, which can mean that you may need to restrict the amount of hot water you use, so you avoid having your spouse/partner getting a cold shower! On the other hand, tankless water heaters can provide a continuous stream of hot water as long as your freshwater and propane supplies last! So if you’re fully hooked up, you can shower all day!
Heating Capacity / BTU ()
An abbreviation for “British Thermal Unit,” BTUs measure the amount of heat needed to raise one pound of water one degree Fahrenheit. So the higher the number of BTUs on a water heater, the more heating power it has. Most conventional water heaters have 8,000 to 12,000 BTUs, while tankless hot water heaters offer 30,000 to 50,000 BTUs. That greater rating is needed in order to heat the water fast enough as it flows through the heater.
Water Flow Rate ()
This is the amount of hot water a heater releases per minute. Because many tanks only hold 6 gallons of hot water, RVers have learned how to slow that water rate down, either by using a shower head with an on/off button or by manually turning off the water periodically. The same holds true for washing dishes in the kitchen sink. Tankless hot water heaters can usually produce at least 2 gallons of hot water per minute… which is more than enough for most RVers needs!
Top RV Water Heater Manufacturers
Most RV water heaters are made by one of the following manufacturers:
- Atwood: Now a part of the Dometic family, Atwood has been making water heaters and furnaces for recreational vehicles and mobile homes since 1964.
- Suburban: Owned by Airxcel, Suburban has been a top manufacturer of RV water heaters, furnaces, ranges and induction cooktops for more than 70 years.
- Truma: The leading European RV component supplier, Truma is rapidly gaining traction in the North American market with their tankless water heaters and combination furnace/water heaters.
- Girard: One of the earliest entrants to offer tankless water heaters to the RV market, Girard has continued to advance their product.
RV Water Heater Maintenance
While they’re not a particularly complicated appliance, hot water heaters DO require a bit of maintenance to keep them in tip-top shape. But when weighing the benefits of having hot water available on-demand while you’re camping, these maintenance chores are a small price to pay:
Cleaning and Descaling an RV Water Heater
Sediments will build up in your RV water heater over time (especially if you RV in areas with hard water), so annual flushing of the appliance should be included as necessary maintenance. To do this, here’s a general overview of the process. You’ll start by turning off the water, gas, and electrical supply to the water heater. Then, you’ll want to wait several hours (or even overnight) for the hot water tank to cool. We recommend turning the gas/electric heating sources off the night before you want to clean the tank out, so the water has had a chance to cool. No matter what method you choose, be very careful to not open your RV water heater with hot water in it! You could seriously injure yourself and we wouldn’t want that.
Next, open your pressure relief valve and remove the drain plug or anode rod to drain the tank. Use an RV water heater flush wand on the end of a garden hose to insert and wash out the inside of the tank. Then fill the tank half full with white vinegar, and fill the rest of the way with water, for a 50/50 vinegar/water mix, and let it sit overnight to dissolve any large sediment pieces. The next day you can thoroughly rinse the vinegar out of the tank and put the drain plug or anode rod back in place. This should give your water heater renewed purpose for at least another year!
If you’re more of a visual learner, you can watch our tutorials on cleaning your water heater here:
Atwood Water Heater
Suburban Water Heater
The RV Water Heater Anode Rod
On Suburban water heaters, which have steel tanks, this metal rod is located in the tank. Anode rods are made of either aluminum or magnesium. The rod attracts ions that would otherwise corrode the tank, allowing those ions to corrode the sacrificial rod instead. And for that reason, it needs to be replaced at least once every couple of years, depending on how much it’s decayed (which will depend on how much you’ve used your RV… and the composition of the water). Hot water heaters made by Atwood don’t have anode rods, as they have aluminum tanks.
Winterizing
If you store your RV during cold winter months, in addition to winterizing your RV’s plumbing, you’ll need to drain the water heater. This ensures that water in the heater doesn’t freeze and damage the tank. You don’t need to get ALL of the water out of the tank, just pull the drain plug or anode rod and let the tank finish draining. The small amount of water that’s left won’t cause damage, as there’s plenty of room in the tank for it to expand as it freezes.
Conclusion
Hot water is a luxury that most RVers have come to love. If you want all of the benefits of having it available at your campsite, whether it be at a fashionable RV resort or off the beaten path in a mountain forest, take a moment to educate yourself on the types of RV water heaters available and the various benefits of each. Then you’ll be able to find the perfect motorhome or travel trailer that affords you a relaxing hot shower whenever you want it!
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Gary Arntz
Thursday 8th of June 2023
i have a problem with my hot water heater! After the water heats up, i can hear the propane heater shut off, then a little while later it will start up again. It will keep on cyclying on and off, without using any of the hot water! any ideas of what i need to do? Thank you
TheRVgeeks
Thursday 8th of June 2023
Sorry to hear, Gary! Based on your description, we'd think it could be a couple of things.
The most likely is that the water heater thermostat is beginning to fail. They're super easy to replace, and not very expensive, so this is probably the best place to start. We have a post about it: How To Replace an RV Water Heater Thermostat
The other thing it could be is mineral build-up in the tank preventing it from heating up as thoroughly/completely... or preventing the thermostat from getting a good reading on the actual temperature of the water in the tank, causing it to fire up again shortly after having finished heating. So you could also try RV Water Heater Flush and Inspection (Suburban & Atwood) and flush the water heater out with a white vinegar solution in order to dissolve any mineral scale that could be the issue.
Lastly, it's possible it's neither of the above and is, instead, an issue with the water heater's circuit board. But this is the least likely (and also the most expensive replacement part), so we'd try the above two first.
Zee
Tuesday 16th of May 2023
Hi Peter & John, very useful article, especially the section about cleaning/descaling.
I can see that you haven't mentioned the motor-aid type. Does that type still exist?
What is your opinion? Also, is there a type that combines: motor-aid, gas, and electric option?
Thanks, Zee
TheRVgeeks
Tuesday 16th of May 2023
Hi Zee. We didn't mention motor-aid because that's less of a TYPE of water heater and more of an additional feature that can be included with one or another type of water heater for your RV. Yes, they do still make them... and you can get one like the Suburban 10-gallon model that has both propane AND 120V electric heating options in addition to the motor aid feature (you can even buy it on Amazon: https://amzn.to/457QKiX).
Motor Aid is, indeed, a helpful feature... it circulates coolant from the engine around the outer jacket of the water heater's tank, heating the water in the tank as you drive. But our only concern about it is that it's now an extra run of coolant hoses to & from the water heater... which is just another possible point of failure.
Barry
Monday 30th of November 2020
I would recommend to regularly check the TPR valve, you can do this by turning off the power buttons as well as the cold water valve. After that place a container under the pie which is directly linked with TPR valve. Lift the valve’s tab upward and release some water. Then let the tab go, in case the water is still flowing you need to drain the tank partway and unscrew the old valve using a pipe wrench.
Terry Nichols
Sunday 15th of November 2020
Hi Peter & John, Great post on “RV Water Heater Tips”. Thank you. My wife and I have been watching your You Tube videos for a longtime. I have gone back and reviewed your videos many times when I need to refresh my memory. I have a 2003 Class A coach that does not have the nice custom by-pass system that your RV has for your water heater. I have been changing the anode every year since we bought it used in 2018 but I have never been able to use the vinegar flush until recently. I found a You Tube channel “Downsizing Makes Cents” https://www.youtube.com/watch?v=-74CQxa5BLU that came up with a great way to get the vinegar into the water heater. You guys should take a look. I added the 50/50 vinegar mix to my water heater and left it in overnight. The electric heating element is now clean. I used my bore scope to inspect the inside of the tank and found that I still have some heavy build up at the seams of the tank. I also found some rusted areas that were exposed after some of the scale came off the walls. I have a few questions I am hoping you guys would be willing to answer: 1. Can I put 100% vinegar in the water heater tank? 2. What is the heaviest mixture ratio of vinegar to water that you would recommend? 3. What is the longest amount of time that you would be willing to leave vinegar in the water heater tank? 4. What will happen, if I leave the water heater as is, with the buildup of scale at the seams? Thanks again for all of your great videos and your help. Terry Nichols
TheRVgeeks
Sunday 15th of November 2020
Hi Terry! Thanks so much for your kind words, great video suggestion for a way to add vinegar without a bypass. Based on what you've said about seeing some scale around the seams... AND seeing some rust visible, here's how we'd answer your questions, in order: 1 & 2 — We wouldn't use more that a 50/50 water/vinegar mix. 3) We wouldn't leave it in there longer than overnight. 4) Based on what you've said, we wouldn't do anything more than you already have. Removing 100% of the scale isn't needed, and might actually be detrimental. What you really want is to remove the scale from the heating element, and the excess from the bottom of the tank, which it sounds like you've done.
We're on our second water heater now in our 15+-year-old rig. Here's how we ended up having to replace it. We did our usual annual flush-out, and noticed a considerable amount of rust and rust flakes coming out with the scale. Then we did the vinegar treatment, but hadn't yet started borescoping it (didn't own one yet). Apparently, that heavy rust we saw coming out before using the vinegar was the beginning of the end, as the tank started dripping into the basement that night. We don't know for sure what was going on in there, since again, we had no borescope yet, but it was getting ready to go, and stripping off every bit of scale and rust apparently pushed it over the edge.
We're sure we were getting close to leaking / needing a replacement anyway, but we probably hastened it by over-cleaning without inspecting to see what was happening. If you're already seeing rust around the edges, leave it alone, and hopefully you'll get many more years out of it. The problem with Suburban heaters is that the steel tank is enamel coated, and once the enamel flakes off, that's where the rust starts. And the acidity in the vinegar probably hastens it a bit, which is why we wouldn't do another treatment this year, or use too high a concentration in the future.
Saturday 14th of November 2020
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