subject: RV Expert Bruce Bernhart on the Basics of the RV Hot Water [print this page] Unlike the water heater in your house which requires little or no user intervention, operating
the typical RV water heater requires you to pay attention to a couple of things.
First and most important, before lighting the water heater gas pilot or turning on any electric
heating function, make SURE that the water heater tank is filled with water!!! Check to be sure
that the water heater inlet and outlet lines are not bypassed with a winterization bypass kit
and that water flows from the hot faucet in the sink or shower. If you fail to check this, you will damage the water heater if you turn on either your gas or electric heating controls. RV water heaters are not designed to be heated without water inside the tank. Tip: Be sure you turn off your water heater controls before you store your RV for the winter. It is easy to forget to do this, and if that control is left in the on position you will have an immediate repair situation to deal with when you roll out your RV for the season. I know first hand because this has happened to me! So, add this to your check list of things to do to prep for storage.
Once you're sure the water heater is indeed full of water, go ahead and turn on the heater.
Some heaters utilize an electric heating element in addition to the standard gas burner. Some
heaters require a pilot and some are direct spark ignition. Check the manual that came with your RV or the data plate on the water heater itself for proper lighting and operating instructions.
Most RV water heaters allow some adjustment of the water temperature. Gas models will
have atemperature adjustment right on the gas valve. Gas/Electric units will also have a
separate thermostat for the electric side, but locations and accessibility will vary. Best to
consult the manual unless you like to play detective. Be careful not to set the temperature too high... it's easy to get severely scalded by water heated beyond 140 degrees.
It is not uncommon to see some weepage from the pressure relief valve on the outside of the
water heater when initially heating a tank of cold water. This is caused by the expansion of the
heated water and indicates very high pressure within the water system. You can open a faucet
briefly to relieve the pressure, but the best permanent fix for this problem (in my opinion) is to
add a small expansion tank to your water system. The expansion tank will absorb the
pressure fluctuations and smooth the water flow in your rig.
Here is a little known secret: If you have a water heater that utilizes a pilot light, you may be
amazed to find that the pilot will heat your water nicely all by itself. Just light the pilot and
leave the gas valve in the 'pilot' position when you park and overnight the water will heat up
and be ready for your shower in the morning. This doesn'twork well in high usage situations, but can be a real propane saver for the frugal RVer!
RV Expert Bruce Bernhart on the Basics of the RV Hot Water