How to Flush a Residential Water HeaterTechnical

Sediment gathering inside the water heater can cause a number of problems. Once the sediment settles to

the bottom of the tank, it can harden. In gas water heaters, this will create a buffer between the bottom of the tank

that is heated by the gas burner and the water itself. The heater will not operate at its design efficiency and you may

notice some rumbling noises. If enough sediment accumulates, it will eventually clog the drain valve.

In electric water heaters, the same accumulation occurs. This sediment will stick to the heating elements

and form a whitish scale. The scale on the heating elements acts as the same buffer in the gas water heaters. The

heat transfer from the elements to the water become less efficient as the scale build up becomes thicker. Like the

gas water heater, if enough sediment accumulates at the bottom of the tank, the drain valve will become clogged.

Accumulation of sediment in the bottom of your water heater can be controlled with periodic flushing.

Flushing will not remove all traces of sediment; however a routine flushing regime will prevent excessive sediment

build up inside your water heater.

1. Turn to power OFF to the water heater at the circuit breaker (electric heater ) or main gas line (gas heater).

2. Fasten a length of garden hose to the drain valve at the bottom of the heater. Put the other end of the garden hose

in the nearest floor drain or snake it outside the home.

3. Close the shut off valve at the cold water inlet line.

4. Open the temperature and pressure relief valve at the top of the heater. Now open the drain valve and allow the

water to drain. You will probably notice some small white particles (called scale or sediment) during the early

stages of the flow.

5. When the water stops, close the drain valve and remove the hose. Also close the temperature and pressure relief

valve at the top of the heater.

6. Open a hot water faucet somewhere in the home. Open the shut off valve at the cold water inlet line. You will

hear the heater start to fill.

7. When you have a steady stream of water from the open faucet, turn the faucet off.

8. . Turn to power ON to the water heater at the circuit breaker (electric heater) or main gas line (gas heater).

Allow the water heater to recover. Check the drain valve one more time to make sure it is tight.

Homeowners should flush their heaters at least every six months. Some areas of the country with hard

water may need to be flushed more often. After flushing your heater a few times you will

discover the schedule that is right for you. Some areas may require MONTHLY flushing due to the water

conditions, thermostat setting and amount of hot water usage by the consumer.

It is impossible to make a ‘one size fits all' maintenance recommendation for every heater. Each water

heater has its unique applications once it becomes installed in your home. Flushing your water heater of sediment

should be a scheduled maintenance event.