Motor home hot water heaters use propane to heat a coil that is filled with cool water from the fresh water tanks. The coil is wrapped around a channel that exhumes the waste from the propane flame. Over time, it may build up with carbon deposits that can reduce performance. Flushing the coil is a simple procedure, but cleaning the flame channel is a challenge as it is a tight, curved space. The average RV owner can clean a hot water heater in about an hour.
Flush the coils by opening the drain valve on the water heater, adding a small amount of bleach to the water tank of the RV, then running the water through the hot water heater (unlit) until it is expelled through the open drain valve. Most drain valves are red locking toggles, clearly labeled, on the front of the unit behind the main door panel. If the valve does not lock into place, then running the water through a sink's hot water tap is an acceptable flush.
Locate the flame channel on the unit. Remove the metal panel that may block it by rotating the Phillips head screws in a counter-clockwise direction. The exhaust side of the channel could also be blocked by a grille, which can be removed in the same manner. The channel is about 2 or 3 inches wide and has a delicate lighting mechanism partially blocking it.
Spray a liberal amount of oven cleaner onto the wire brush, then rake the interior of the flame channel's walls. Soot and carbon will spill out of both ends of the channel--the bulk of the waste can be scooped into a garbage can. Several wire brush treatments will clean the channel. Be careful not to bump the propane ignition hardware with the brush.
Units with an electric start can be dried with a lint-free rag, gently pushed in as far as possible with the broom handle, then removed. Units without an electric start can have pressurized water run through the channel with a garden hose to remove all debris. The unit can then be dried with the rag or air dried.
Replace the grille and channel covers by turning their screws in a clockwise direction.
Items you will need
- Long 2-inch wire brush
- Garden hose
- Spray oven cleaner
- Broom handle
- Lint free rag
- Turn off the propane tank before starting this procedure. The water heater can also be flushed with the garden hose by linking it with the pipes in the back of the heater, but this requires removal of the unit.
- The oven cleaner residue must be wiped or rinsed out before use.