How to Flush Your Water Heater

Sediment is the silent enemy of every residential water heater. Over time, minerals from your water supply settle at the bottom of the tank, creating a thick layer of sludge that acts as an insulator between your burner or heating element and the water itself. This forced inefficiency makes your unit work harder to maintain temperature, which leads to premature tank corrosion and higher energy bills. Performing a proper flush is a straightforward maintenance task that pays for itself in longevity and performance. Done well, you will see a clear, sediment-free stream of water exit your hose, signaling that you have cleared out the accumulation. This process ensures your hot water remains consistent and your heater operates as quietly and efficiently as the day it was installed.

1. Kill the Power First. For electric heaters, switch off the circuit breaker. For gas heaters, turn the gas control knob to the Pilot setting or switch it to Off.
2. Route the Water Out. Attach a standard garden hose to the drain valve located at the bottom of the water heater tank. Direct the other end of the hose to a floor drain, a basement sump pump, or outside away from your foundation.
3. Break the Vacuum. Locate the Temperature and Pressure (T&P) relief valve near the top of the tank and lift the lever. This breaks the vacuum inside the tank, allowing the water to drain smoothly.
4. Release the Sediment. Use a flathead screwdriver or the built-in handle to open the drain valve at the base of the tank. The water will begin to flow through the hose, likely appearing cloudy or brown at first.
5. Power Flush the Tank. Briefly turn the cold water supply to the heater back on for a few seconds while the drain valve is still open. This 'power flush' helps stir up and push out stubborn sediment trapped at the bottom.
6. Refill and Restore Power. Close the drain valve, disconnect the hose, and turn the cold water supply back on to refill the tank. Once the tank is full, turn the power or gas back on.