It is important to Flush the RV Water Heater tank in order to extend the life of the inner tank and to eliminate the buildup of mineral deposits. As a result of our traveling to different places around the country in our RV, we encounter water with varying degrees of hardness or mineralization. This should be done two or three times a year, especially at the start of your RV season. Mineral deposits settle to the bottom of the tank, so simply draining the tank will not usually rinse out these deposits. The smaller particles move up the hot water line and clog the shower head and sink aerators. They must be cleaned individually.
Flush the RV Water Heater Procedure
- Turn off the switches for gas and if so equipped, electric hot water. Make sure the water inside has cooled.
- Turn off the water pump and the city water connection to de-pressurize the system.
- Drain the water heater by opening its drain valve (or removing the plug/anode). You can also lift the pressure and temperature relief valve handle to increase the flow. To aid in draining, open all hot water faucets throughout the RV.
- Now is the time to use a tank flush tool and thoroughly flush out the tank and remove mineral deposits trapped below the drain opening. The Tank Flush Tool is available at on Amazon and most RV parts stores.
- Close all hot water faucets opened earlier and turn on the city water or the water pump (the higher the pressure, the better).
- Open the pressure and temperature relief valve and allow water to gush from the drain opening as fresh water rushes in.
- Allow this flushing to continue for five to ten minutes. This will remove any stagnant water along with any residual mineral deposits that may remain.
- After flushing, turn off the water source, reinstall the drain plug/anode (or close the drain valve) and close the pressure and temperature relief valve by allowing the lever to snap shut.
NOTE: Sacrificial anode rods are used in water heaters made by Suburban. Atwood water heaters do not use an anode rod and have a plastic drain plug. Inspect the anode rod and replace if more than 50% is missing.
- Turn on the water pressure again and open all the hot water faucets inside the coach until water flows freely from all hot faucets.
- Now, turn off the water and all but one of the hot faucets, then open the pressure and temperature relief valve again to release any water and to establish a cushion of air on top of the water in the water heater. When water stops dripping from the pressure and temperature relief valve, close it and the last hot faucet inside the RV. The heater is now ready for use and you can turn on the gas or electric switch to heat the water in the tank.
You should Flush the RV Water Heater each season if you are not a full-time RVer. It should also be done when you are in a hard water area for more than a week or so.