Q. Our water heater rumbles and makes odd noises upon startup. It did not do that originally, when the coach was new. What can we do?
A. Water heater noise can be caused by sediment buildup in the bottom of an RV water heater. This may happen when sediment collects on the heating element, then drops to the bottom of the heater and becomes crystallized on the electric coil inside. When hot water is used, the gas burner or the heating element comes on, and the sudden heat makes the moisture trapped in these particles flash boil and causes the rumble you hear on startup. Be sure to change the anode rod every year or so. You also need to insert a small piece of tubing into the end of a water hose and stick it into the drain, or anode, hole to rinse the tank clear of debris. This should eliminate the noise.