Are you worried about routine preventive service on your water heating system? Assuming you have a standard propane water heater (not an Aqua-Hot or Hydra-Hot or other on-demand system) Here’s what you’ll need to know;
All standard water heaters (ie. with tanks) will perform better if they are annually drained and flushed. This removes calcium and lime and improves the water quality and the heating efficiency. For your annual maintenance please follow these instructions:
CAUTION: If your water heater has an optional 120 volt electric heating element, NEVER allow this element to become energized (ie. Turned On) when the tank is empty, as the element will burn up in 15 seconds or less.
- Turn off the water supply to your RV. Turn off the water pump if it’s on. Turn off all switches for the water heater and disconnect the power cord between the RV and the city electricity supply. Find a faucet where you can easily unscrew the aerator, and remove the aerator. Turn that faucet on, (hot and cold) until the water stops flowing.
- Go outside and open the hatch cover for the water heater, and remove the drain plug which is located near the bottom of the water heater. Atwood water heaters utilize a heavy white plastic ½” plug, while water heaters made by Suburban Manufacturing utilize a long metal anode rod. (more on that later)
- With the drain plug (or anode rod) removed, let all the water drain out of the hot water tank. The water will “burp” out of the drain plug hole. Don’t lift the lever on the brass Pressure/temperature Relief valve (to let air into the tank) as it may leak afterwards.
- After draining the tank, attach a water heater flush tool (available in the Parts section of my website) to your white supply hose and force water into the hot water tank by inserting this tool into the drain plug hole. Use a stroking & rotating action to direct water to all surfaces of the tank, especially the bottom. You may notice a “sandbar” or calcium on the bottom of the tank. Keep flushing and draining the tank until all the calcium is gone. It’s going to make a mess on the ground but it’s not a health hazard
- If the drain plug was a heavy white plastic ½” plug, buy a new Atwood drain plug from your RV store, (or on this website) and insert it. It is Atwood part number 91857. Plugs obtained from sources other than Atwood will likely not be water tight and will fail prematurely due to the heat of the water.
- If the drain plug was actually a metal anode rod with a threaded end, you must check to see if it is mostly eaten away. Swap it out if it is seventy five percent gone or more. The anode rod is installed to protect the steel walls of the tank from being rusted by the water. A new anode is 8-1/2” long and ¾” in thick, and can be purchased at all RV shops or at the RV parts section of this website. The Suburban part number is 232768. When installing the anode, use Teflon tape or paste.
- Turn off the hot + cold faucets inside the rig and turn on the water supply or water pump.
- You’ll hear the water heater tank start filling up, and you might hear a strange “singing” sound from the water heater. This is air being forced past the one-way valve at the output of the water heater. It will stop singing when the air is all expelled. Go to the faucet where you removed the aerator and turn on the hot side, and notice water and bursts of air coming out of that open faucet. The water being expelled may look cloudy from floating calcium & lime debris, which would have plugged up the aerator.
- When the air pockets have stopped coming out of this open faucet, and the water is clear of calcium, turn off the faucet and reinstall the aerator. Test the faucet with the aerator installed. The water should have normal flow and appearance.
- Check for leaks around the new drain plug (or anode) and tighten if needed. Turn on the propane side of the water heater and confirm that it ignites. If there is no electric heating element, leave the propane side on until the propane burner shuts itself off, and then make a final leak inspection. Turn off the propane side and turn on the electric side if equipped. You can’t hear or see the electric side operating, but the water will be hot in about 30-40 minutes with the propane side off. Congratulations, you’re done!