Drain your water heater tank by removing the drain plug. Approximately two quarts of water will remain in the bottom of the tank. If you no- tice during the draining that the water is flowing sporadically or slowly, instead of flowing freely, you should open your relief valve to allow air into the tank.
If the water does not flow freely, take a small gauge wire or coat hanger and push through the drain opening to eliminate any obstructions.
After thoroughly draining the tank, flush the entire system from the water inlet all the way to the holding tank. To flush, use four parts vinegar mixed with two parts of water. If you decide to use air pressure (55 PSI max.), it may be applied either through the inlet or outlet on the rear of the tank. It may also be applied through the relief valve port. In this case, it will be necessary to first remove the relief valve.You may then insert your air pressure through the relief valve support flange. In either case, with the drain valve open, the air pressure will force the remaining water out of the tank. If air pressure is unavailable, you may flush your tank with fresh water. Fresh water should be pumped into the tank with the assistance of the on board water pump or with the assistance of external water pressure. Once again, external pressure may be pumped into the unit either through the inlet or outlet found on the rear of the water tank, or using the relief valve in- let located on the front of the unit.
Continue this flushing process for approximately five (5) minutes allowing ample time for the fresh water to agitate the stagnant water on the bottom of the tank and force the deposits through the drain opening.
Upon completion of the steps above, close the drain plug as well as the relief valve. Refill with fresh water, circulate and rinse.
If you use your vehicle frequently or for long periods of time, flushing the water heater sever- al times a year will prolong the life of the water heater storage tank.