How to Flush a Hot Water Tank

It is important to flush a hot water tank at least once a year to clear sediment from the unit. The sediment that builds up is grit, sand, gravel or dirt. When the sediment builds up in the hot water tank it can decrease the amount of water the tank holds. Furthermore, this buildup can cause the unit to run less efficiently and even clog the drain valve on the water heater. To save money on your energy bill and reduce the likelihood of the unit malfunctioning, hot water tank flushing is periodically necessary.

Things You'll Need

• Garden hose
• Large screwdriver

Instructions

1. Power off the hot water tank. Turn the valve on a gas water heater tank to the "Pilot" position. This is very important---it will keep the burners from igniting during the flushing of the unit. For an electric water heater, turn off the circuit breakers going to the unit. Shut off the cold water valve as well.

2. Screw a garden hose into the round, threaded drain valve. This is located at the bottom of the hot water tank.

3. Place the open end of the garden hose outside where it can safely drain. Keep in mind that the water can be very hot, so keep it away from plants or other areas that cannot sustain the heat.

4. Lift the lever on the temperature or pressure relief valve located at the top of the hot water unit.

5. Allow the water to flush through the garden hose by opening the drain valve. Be careful if you are opening a drain valve on an older tank as these are made of plastic and can easily break.

6. Use a large screwdriver if the drain valve gets clogged with sediment. Sometimes the sediment forms into big chunks that can clog the valve. Allow the unit to cool down, then disconnect the garden hose from the drain valve to break up any large pieces of sediment. Then reconnect the garden hose and allow the water to flush again.

7. Monitor the water coming out of the open end of the garden hose. When the water comes out clear, the flushing is complete.

8. Close the drain valve and detach the garden hose. Close the relief valve and turn on the cold inlet valve.

9. Turn on a hot water faucet inside the home. Allow the water to flow until it is free of air bubbles. You may then power the water heater back on and light the pilot light if it is a gas unit.

Tips & Warnings

• The water from the hot water tank can be very hot so keep children and pets away while flushing.

References

• Monroe Township Utilities Department
• Chili Pepper Appliance