How To Clean Sediment From A Hot Water Heater

September 17, 2024

Cleaning sediment from a hot water heater is an important maintenance task to keep it running efficiently and to prolong its lifespan. The build-up of sediment, which usually consists of minerals such as calcium and magnesium, can reduce the heater's efficiency and damage the tank over time.

Here's a general guide on how to clean sediment from a hot water heater, based on common practices:

Tools and Materials Needed:

Garden hose
Bucket
Socket wrench or flathead screwdriver (if needed for opening the drain valve)
Teflon tape (optional)
Gloves and safety glasses (for protection)

Step-by-Step Instructions:

1. Turn off the Water Heater

For gas heaters: Turn the thermostat to the "Pilot" setting.
For electric heaters: Turn off the power at the circuit breaker.
This step ensures that no heat is generated while you're draining the tank, preventing burns and damage to the heater.

2. Turn off the Cold Water Supply

Find the cold water inlet valve at the top of the water heater and turn it off. This will stop additional water from entering the tank.

3. Connect a Garden Hose to the Drain Valve

Attach one end of a garden hose to the drain valve at the bottom of the tank. Run the other end of the hose to a drain or outside area where water can safely flow without causing damage.

4. Open the Drain Valve

Open the drain valve to allow water to start draining from the tank. Depending on the model, you may need a flathead screwdriver or socket wrench to turn the valve.
Be careful, as the water will still be hot. It's a good idea to let the tank cool for a couple of hours if you can.

5. Open a Hot Water Faucet

Open a nearby hot water faucet (such as in a bathroom or kitchen) to allow air into the system. This helps the water drain more smoothly from the heater.

6. Drain the Water

Allow all the water to drain out of the tank. You may notice sediment or cloudy water flowing out, which is the mineral build-up.
If the flow slows down or stops prematurely, try turning the cold water supply back on briefly to flush out more sediment. This burst of water can help loosen up any remaining build-up.

7. Flush the Tank

Once the tank is drained, with the drain valve still open, turn the cold water supply on for a few seconds to flush out any remaining sediment at the bottom of the tank.
Repeat this process several times until the water runs clear from the hose.

8. Close the Drain Valve and Remove the Hose

Once you're satisfied that the tank is clean, close the drain valve securely and remove the garden hose.

9. Refill the Tank

Turn the cold water supply back on to refill the water heater. Keep the nearby hot water faucet open until water flows out of it smoothly, indicating that the air has been purged from the system.

10. Turn the Power or Gas Back On

Once the tank is full, turn the power back on at the circuit breaker for electric heaters or turn the gas control back to its normal setting for gas heaters.

11. Check for Leaks

Check around the drain valve and the tank's base to ensure there are no leaks.

Additional Tips:

Inspect the anode rod: While the tank is drained, it's a good opportunity to check and replace the anode rod if needed. The anode rod helps protect the tank from rust and should be replaced if it's heavily corroded.
Annual Maintenance: It's recommended to flush your water heater annually to prevent heavy sediment build-up. If you live in an area with hard water, you may need to do this more frequently.

By following these steps, you'll keep your water heater functioning efficiently and extend its lifespan.

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