Draining a Hot Water Tank Properly

31 August 2015
 Categories: , Blog


With proper maintenance, a hot water heater normally lasts for many years. However, over time sediments can develop inside the tank due to sand that has gotten in the local water system in your community. These sediments settle inside the tank and may eventually clog the drain valve so that the tank can no longer be drained when needed.

If sediments are not removed from the water tank periodically, the quality of the water that passes through the heater as it is heated is lowered. It is important to drain and flush your hot water heater annually. These are the steps to take to do this properly.

Cutting Off the Power and Water Supply 

You must first cut off the power and water supply to the hot water tank. Electric water heaters should have a switch to turn the power off in your breaker box. Gas water heaters have a switch near the thermostat and this should be turned to the pilot setting.

When the power is turned off, allow the tank to cool for a couple hours before draining the hot water to prevent getting burned. Attach a drain hose to the drain valve on the water heater that is long enough to reach the nearest sink. Then turn the shut off valve for your cold water pipe off so that water no longer flows into the water heater.

Draining the Hot Water Tank 

Place the drain hose in the sink that is nearest the hot water heater. Turn on your hot water faucet to provide an airway so that the water drains from the tank more easily. Open the drain valve on the water heater that is attached to the hose. Leave the hose inside the sink until all the water drains from the tank completely.

Flushing the Sediment from the Tank 

Once the tank has drained, it is important to also flush any remaining sediment from inside it. This is done by turning the water supply back on and allowing water to run through the tank and come out of the hose into the sink. Continue to do this until the water runs clear.

Refilling the Hot Water Tank

When the flushing is completed, turn the hot water faucet back to the off position, remove the hose from the drain valve and let the hot water tank fill back up with water. Be sure the tank is full before turning the power back on to it to avoid damaging the heating element.

In some areas, it may be necessary to drain your hot water heater more often than once a year. Check with your local water company and if there is a high mineral content in the water in your community, this may need to be done more frequently. For assistance, talk to a professional like Fast Service Plumbing & Gas Fitting.