Before you start
- If you rent your water heater, check your agreement; the rental company may do maintenance. If the tank is very old and has never been flushed, opening the drain valve can stir sediment that keeps the valve from closing. In that case, it may be better to call a plumber.
- Set a gas tank's control to pilot or vacation, or shut the breaker for an electric heater.
Draining
- Close the cold valve feeding the heater. Fit a garden hose to the drain cock near the floor and run its far end to a floor drain. Open any hot faucet upstairs to let air in behind the water, and only then open the drain cock.
- The water will be hot. Keep children and pets away.
Flushing
- When the tank is empty, open the cold supply briefly to stir sediment and flush it out. Carry on until the stream from the hose runs clean.
- Shut the drain cock, take the hose off and refill with that upstairs hot tap still open, closing it once it runs without sputtering.
Quick checklist
- Gas to pilot or breaker off
- Shut the cold inlet
- Drain through a hose
- Flush until clear
- Refill before restarting
Restart
- For gas, return the setting to its normal position. For electric, make sure the tank is full before restoring power, or the elements can burn out.
- Check the drain valve for drips.
Signs of sediment
- Grumbling or crackling as the burner fires, showers going cold earlier than they did, and bits of white or tan grit in aerators all point to sediment. With moderately hard local water, the grit layer grows every year.
- A yearly flush keeps it under control and helps the tank reach its expected life.
Richmond Hill note: most houses here sit on York Region municipal water with fairly hard supply, and many basements have a floor drain tied to the sanitary lateral. Mention both on the phone; it changes what goes on the truck.
Want a second opinion on your own pipes first? Dial (365) 363-1575; the person answering holds the wrench.