RV Repair Manual
for the RV Do-It-Yourselfer
By Lois Powell
RVers want lots of hot water, so we light our water heater and forget it. Unless there is a problem, then we're stuck! So, this article may make the RV water heater workings a bit easier to understand.
The basic RV water heater is LP gas (pilot light) with a 6 gallon tank. The inner tank is bisected with a tube that is heated by a gas valve. This valve does double duty as a thermostat, heating the water to the proper temperature, and as a safety valve which will shut off the LP when the pilot goes out. The water travels into the tank at the bottom, surrounds the tube and is heated, then is released out the top. The tank will fill before water can go through the rest of the camper's water system.
An upgrade to the basic gas pilot model is DSI, or direct spark ignition, which is lit from inside the camper. Also available are LP gas and electric models. A heating element is added as an alternate way to heat the water. Some motor homes have water heaters with heat exchangers that pipe the water through the engine compartment while traveling, so you have hot water when you stop for the night!
There are two main manufacturer of the RV water heater: Atwood and Suburban. They come 3, 6, 10 and 12 gallon models. The following are tips to help you keep your RV water heater trouble free:
Always make sure your water heater is full before lighting. You can check by opening a hot water faucet and waiting until there is a steady flow.
Drain and flush your water heater after every trip. On Suburban models the anode rod is removed to drain the tank. Atwood has a plug usually located in the bottom left corner of the water heater. Get to both these drains by opening the outside WH door.
Check the exterior vent and burner area for mud daubers, spider webs and anything else that will obstruct the air flow.
Winterize properly. If your RV is not equipped with a by pass, install one now. This will keep the antifreeze from filling your tank.
A common problem found with RV water heaters is foul smell - like rotten eggs. This is caused by high sulphur levels. Though unpleasant, it is not harmful. Flush and sanitize the water system to get rid of the smell. You can use vinegar or bleach to do this. There are water fresheners available that will sanitize without the bleach smell. Remember to flush with clean water after sanitizing.
Another common problem is water leaking at the pressure relief valve. This is caused by the normal air pocket at the top of the water tank being absorbed by the water. The cure for this is to turn off the water heater and let the water cool. Then shut off the water supply to the water heater, open a faucet inside your camper to let off the pressure, open the pressure valve on the water heater and let the water flow until it stops on its own, then snap shut the valve, close the faucet, and turn the water supply back on. These are not signs of a defective water heater.
Other issues such as sooting, or problems with the water heater staying lit could be signs of trouble with the gas valve or circuit board, and should be checked by a certified RV technician.
For more information about the RV Parts noted above, please check out RVPartsDealer.com where you will find a huge variety of the newest RV Water Heater.