How To Drain Your Water Heater

Water heaters can give you years of trouble-free service, but a little water heater maintenance can help extend the life of your tank beyond its minimum rated service period. Many water tanks suffer from lack of maintenance, which can deteriorate the tank and cause it to fail prematurely.

To help keep your hot water tank operating properly, make a maintenance plan that includes draining the tank annually. This will discourage the build-up of sediment in the tank and will help extend the tank’s life. To drain the tank, you’ll need a standard garden hose and a safe place to put 40 gallons or more of hot water.

If your water heater is electric, cut the power to the tank at the breaker box before you do anything else. If your tank uses natural gas, turn the temperature control to the “pilot” setting, or to “off” depending upon how the control is marked.

Once the power/fuel is cut, attach the hose to the tank’s drain valve. The drain valve looks like a hose spigot, may be made of plastic or metal, and is threaded to accept a standard garden hose. Don’t open the drain valve yet – just get the hose attached to the valve.

Run the hose to a working floor drain, sump well or to the outside, if the tank is on the first floor of your home. Remember, the water that drains from the tank will be hot, so be sure to dispose of it safely!

Turn off the cold water supply to the tank, and open a hot water tap on one of your faucets. This will allow air to enter the tank and push the water out through the drain. Finally, open the drain valve on your hot water tank. Monitor the tank as it drains to prevent accidental flooding and to verify that the tank is draining.
When the tank is drained, open the cold water supply and begin refilling the tank. Don’t close the drain valve; the goal here is to flush any accumulated sediment out of the bottom of the tank.

When the water runs clear from the drain hose, close the open hot water tap and the drain valve. Allow the tank to refill. Once the tank is refilled, reapply power or re-ignite the gas and allow the tank to begin heating again.

Next week, I’ll discuss the pressure relief valve on your hot water heater, and show you how to test the valve for proper operation. In the mean time, if you have trouble with your water heater, or would like Boston Standard Plumbing & Heating to perform maintenance on it, please give us a call anytime at (617) 288-2911.