How to Flush a Tank Water Heater

Before you begin

Check whether your heater is rented; some rental agreements prefer that the provider does maintenance. Read the label for the maker's instructions. You will need a garden hose, a bucket and gloves. What comes out will be hot enough to burn skin.

Step by step

1. Shut the heat source. On gas units, turn the dial to pilot or vacation; on electric, flip its breaker off.
2. Close the cold supply valve on the pipe entering the top of the tank.
3. Attach the hose to the drain valve near the bottom and run it to a floor drain or outside.
4. Crack a hot faucet upstairs to break the vacuum.
5. Turn the drain valve and watch the flow until it runs clean. A full drain is not always necessary; several buckets often shows how much sediment is there.
6. Agitate the bottom. With the drain still running, give the cold inlet a short burst to churn up the remaining grit, then shut it.
7. Shut the drain and take off the hose. Reopen the cold inlet and wait until the hot faucet upstairs flows smoothly with no sputtering.
8. Relight or re-energise only after the tank has refilled completely.

If the drain valve will not close

Older plastic drain valves can weep after use. Thread a hose cap onto the outlet as a temporary seal and call us to replace the valve with a brass one.

How often

Once a year suits most Brampton homes. If you have never flushed an older tank, do it gently; disturbed sediment can clog the drain valve. If the water stays cloudy or the tank is over ten years old, read our water heater lifespan guide.

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