How to Dissolve Water Heater Sediment

Even newer water heaters need flushed to dissolve and remove sediment.

While a few descaling products claim they can dissolve the sediment in a water heater, manufacturers of water heaters recommend flushing the tank as the way to deal with mineral deposits. Because sediment from mineral deposits settles to the bottom of the tank, flushing it out is the most efficient method. Sediment particles in a water heater come from the mineral deposits in water. The harder the water, the more sediment you can expect to have in your water heater. While they pose little health risk, they can clog pipes and other parts in the water heater and prevent it from operating properly. Installing a water softener is the best way prevent sediment, but if you have existing sediment, flushing it from the tank removes the majority of the mineral deposits. After flushing the tank, adding new water to the tank usually can dissolve remaining deposits so they can be flushed away.

Things You'll Need

• Water hose
• Bucket

Instructions

1. Turn off the gas valve or unplug the electrical cord, and shut off the cold water valve.

2. Twist a water hose to the end of the drain valve, and put the other end of the hose into the drain.

3. Open the relief valve to drain the water. Most relief valves have a release lever you flip up to open.

4. Drain the water until you no longer notice sediment emptying from the hose. To check whether there is still sediment in the water, place the hose in a bucket, fill it with water from the tank and inspect it for sediment.

5. Close the relief valve, and turn on the cold water valve if sediment remains in the water once the tank is fully drained. The cold water running into the tank should dissolve the remaining sediment so it flows out. After the tank is full, turn off the water valve and drain the tank again.

Tips & Warnings

• Flush the water heater about once every one or two years to prevent sediment buildup.

• If the valve clogs while you are flushing it, turn on the cold water valve to break up the clog.

References

• Peterborough Utilities Group: Frequently Asked Questions