As RVers, we’re passionate about keeping things clean and in working order. Forget to sanitize our fresh water tank on a regular basis? No way! Get those holding tanks professionally cleaned every year? You bet! But what about your hot water tank?
How an RV hot water heater works
There are two primary makers of RV hot water heaters, Suburban, used in most fifth wheels, and Atwood, (which is now owned by Dometic, the popular RV appliance and product manufacturer), used primarily in travel trailers. Atwood heaters tend to be smaller (6- or 10-gallon) while Suburban’s are mostly larger (12- or 16-gallons in capacity).
There are three main ways to heat the water in an RV hot water tank: Propane, electricity, or the heat of the engine. Electric is usually the most convenient, however, using the heat from your engine is the most economical (the RV’s drive engine gets hot naturally and you’re just using some of the excess heat to heat up water). Most RV water heaters are dual fuel: electric and propane. Almost everyone with a dual-fuel water heater uses electricity because it’s easier (there’s no pilot to light) and more convenient (just switch on the heater and in a short time, you have hot water).
You can use both electricity and gas at the same time — doing so will result in hot water much faster. The water temperature is set at 140 degrees — HOT! — and is meant to be mixed with cold water via a mixing valve to be less scalding (though it can still be pretty hot). You can get after-market thermostats to attach to the hot water tank to fine-tune water temperature.