Flushing Water Heaters

Most home water supplies contain sediment and minerals that can end up at the bottom of your water heater. In gas water heaters the sediment insulates the tank from the flame underneath, increasing energy usage, causing rumbling noises, and eventually tank failure. In electric water heaters, sediment builds up and reduces tank’s capacity.

You can also remove sediment from your water heater by flushing it out through the drain valve installed at the base of the tank. Connect a garden hose to this valve and run it outdoors or to a floor drain. You can also collect the water and sediment in a bucket.

Water-heater manufacturers install plastic drain valves because of low price and because these low-profile valves aren’t apt to be damaged during shipping. However, these washer-and-seat valves aren’t don’t allow enough water through them to effectively remove sediment. If you buy a new water heater or have a relatively new one, buy a 1/2-inch metal ball valve and install it in place of the original drain valve. Flushing water through this wide-open valve into a bucket a couple times a year could extend the life of your water heater by a few years.

Before flushing turn a gas water heater to pilot and disconnect an electric water heater at the circuit breaker and connect a garden hose to the drain. Finish this flushing procedure by closing the drain valve, disconnecting the garden hose, turning the cold water supply valve back on, and refilling the tank letting air escape from a open faucet. Remember to turn the water heater back on.

Every water heater has a “dip tube” that is connected to the cold water inlet and extends downward to within a few inches of the tank’s bottom. Standard dip tubes are straight, but some new water heaters have dip tubes that are curved or that have multiple outlets designed to swirl the water at the tank’s bottom and keep sediment from piling up. If you plan to buy a new water heater, these designs offer a significant improvement over older dip tubes and are worth the extra cost.

For more information, contact the folks at Water Heater Rescue: www.waterheaterrescue.com

The Homeowners Handbook to Energy Efficiency contains simple, practical energy-efficiency ideas.