How to Drain a Water Heater

Draining your water heater removes any sediment in the bottom of the tank. Here’s how to go about it:

  1. Turn off the gas or electricity to the water heater.
  2. Close the cold water supply valve coming into the water heater.
  3. Attach a garden hose to the drain at the bottom of the tank.
  4. Run the hose outside on the ground.
  5. Open the drain valve on the tank.
  6. Release the pressure relief valve on top of the tank.
  7. Allow the water in the tank to drain out.
  8. Once the tank has drained, open the cold water supply valve for a few minutes to flush out any sediment.
  9. Close the drain valve and pressure relief valve.
  10. Remove the hose from the drain valve.
  11. Allow the tank to fill.
  12. Turn the power back on or relight the pilot light.


  1. Hi Danny
    Pressure relief valve manufacturers believe the valve can be damaged if it is allowed to snap closed. For this reason they are now making valves that will not open fully unless your holding the lever. When you release the lever it will close, preventing the snap that can cause the damage. I always open the hot side of the kitchen faucet(the easiest to repair if it gets clogged with calcium deposits). Allow the water in the tank to set for an hour after its filled so that any sediment or calcium deposits that are left will settle in the bottom of the tank and not in your plumbing lines.

  2. My tank is leaking ans has water around the bottom. There is rust and looks nasty. I don’t have the money for a plumber and no husband or companion to help. What can I check and do to see if can be repaired.

  3. Installed new 75gal Rheem HWH last year. I have recirculating hw pump system. With new Rheem HWH the water will sometimes be hot (per dial setting) and after few minutes it becomes warm and no longer hot. I can dial it UP to be hotter in which case it gets very hot but again after few minutes of running it becomes warm (not cool or cold). It just does not maintain the set dial temp.I did not have this issue before. Any idea? IS it the nature of the Rheem or is it defective?


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