How To Drain a Water Heater Tank

Posted November 22, 2016

One of the best ways to extend the life of your water heater and ensure it operates efficiently is to flush the tank annually to remove sediment buildup. The process is straightforward, here are the steps:

  1. Shut off the water supply. Locate the cold water supply valve at the top of the water heater and turn it to the off position.
  2. Turn off the water heater. If you have a gas water heater, simply turn the thermostat knob to the “pilot” setting. If the water heater is electric, turn off the power at the breaker panel.
  3. Attach a garden hose to the drain valve located near the bottom of the tank. Place the other end of the hose near a floor drain, in a bucket (have several large buckets to empty into and rotate them if needed) or outside the home. CAUTION: Even though a water heater may be off for hours, the water in the tank may still be hot enough to scald.
  4. Open a hot water tap. Open a hot water tap on a floor above that is nearest the water heater. This will relieve pressure in the system, helping the water drain from the tank.
  5. Open the drain valve.  After all the water has drained from the tank, turn the cold water supply at the top of the tank back on for a moment. This will clear out any remaining sediment. Repeat this step until the water runs clear.

When you're finished draining the tank, return it to operating condition by following these steps:

  1. Close the drain valve
  2. Remove the hose
  3. Turn on the cold water supply and refill the tank.
  4. Return to the hot water tap you opened earlier. Once cold water begins to flow from the tap, turn it off.
  5. Turn the gas valve back on from the pilot position or turn electricity back on to the tank.
  6. Check the valve opening to ensure it's not leaking.

IMPORTANT: Always read and follow all manufacturer’s directions and warnings for your particular water heater. Some water heater tanks need to be completely filled to avoid damage to the gas burner or heating elements. Need help maintaining your water heater? Call ABC Plumbing, Sewer, Heating, Cooling and Electric. We can help with all your home plumbing needs.

Also check the following blog post: What's the Purpose of a Water Heater Expansion Tank?

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