How to Flush Sediment from Your Water Heater

Sediment is the silent enemy of your water heater, gathering at the bottom of the tank as minerals from your water supply settle and harden over time. Left unchecked, this layer of grit acts as an insulator, forcing your heating elements or gas burner to work twice as hard to heat the water while potentially causing that rhythmic 'popping' or 'rumbling' sound that echoes through your pipes. Performing an annual flush is one of the most effective ways to extend the lifespan of your unit. When done well, the water exiting your tank transitions from cloudy and debris-filled to crystal clear, ensuring that your system operates at peak energy efficiency and continues to provide consistent, reliable hot water throughout the home.

  1. Kill the Power First. Turn off the power at the circuit breaker for an electric heater, or turn the gas control knob to the pilot position for a gas unit. Never drain a water heater while the heating elements or burners are active, as you could burn out the elements or damage the tank.
  2. Route the Drain Path. Attach a standard garden hose to the drain valve located at the bottom of the tank. Run the other end of the hose to a floor drain, a utility sink, or outside to a safe location.
  3. Break the Tank Vacuum. Lift the lever on the temperature and pressure relief (T&P) valve near the top of the tank. This breaks the vacuum inside the tank, allowing the water to flow out freely.
  4. Drain Until Clear. Use a flathead screwdriver or the built-in handle to open the drain valve at the base of the tank. Let the water flow until the tank is completely empty and the water runs clear of sediment.
  5. Stir and Flush Again. Turn the cold water supply back on briefly to stir up any remaining loose sediment at the bottom of the tank. Repeat the draining process until the water coming out of the hose is clear.
  6. Purge and Restore Power. Close the drain valve, disconnect the hose, and close the T&P relief valve. Turn the cold water supply on and keep a hot water faucet open in a nearby sink until all air is purged from the lines, then restore power or gas.