How to Flush Your Water Heater to Remove Sediment Buildup

Drain your water heater annually by connecting a garden hose to the drain valve and flushing until water runs clear, which removes sediment that reduces efficiency and shortens tank life.

1. Kill the Power First. Switch off the circuit breaker for electric water heaters or turn the gas valve to pilot position for gas units. Locate the cold water inlet valve at the top of the tank and turn it clockwise to shut off water flow to the heater.
2. Give It Time to Cool. Wait at least 2 hours for the water inside to cool to a safe temperature. Hot water can cause severe burns, so this step prevents injury when you begin draining the tank.
3. Route the Drain Path. Attach one end of a garden hose to the drain valve located near the bottom of the water heater. Run the other end to a floor drain, outside area, or large bucket that can handle the full tank capacity.
4. Break the Vacuum. Turn on any hot water faucet in your home, preferably one on the highest floor. This allows air into the system and helps the tank drain faster by preventing a vacuum.
5. Start the Drain Flow. Turn the drain valve counterclockwise to open it completely. Water will begin flowing out through the hose. The initial water may be discolored or contain visible sediment particles.
6. Stir Up the Sediment. Once the tank is empty, turn the cold water supply back on while keeping the drain valve open. This creates a flushing action that stirs up and removes sediment from the bottom of the tank. Continue until water runs clear.
7. Seal and Refill. Close the drain valve tightly and disconnect the hose. Turn off the hot water faucet you opened earlier. Turn the cold water supply valve back on and let the tank refill completely before restoring power or relighting the pilot.
8. Confirm Everything Works. Turn the circuit breaker back on for electric units or return the gas valve to the on position. Wait 30 minutes, then test hot water at a faucet to ensure the system is working properly.