How to Flush a Water Heater, and How Often Hampton Roads Homes Should

Why a Water Heater Flush Is Worth Doing Every Year

Every gallon that enters a tank carries a little dissolved mineral, mostly calcium and magnesium. Heat drives it out of the water, and it settles on the bottom as sediment. Over a few years that layer can grow several inches deep, and it sits directly between the burner or lower element and the water you are paying to heat.

That layer costs you in three ways. The heater runs longer to reach the same temperature, so the gas or power bill creeps up. The tank bottom runs hotter than it was designed to, which stresses the steel and the glass lining. And the sediment takes up space, so the tank holds less hot water than the label says. A family that used to get through four showers suddenly runs cold on the third.

A yearly water heater flush clears most of that before it hardens. It is the cheapest maintenance you can do on a tank, and it is one of the main reasons some heaters last 12 years and others fail at 7. Our post on how long hot water heaters usually last covers the rest of what decides that number.

What That Water Heater Popping Noise Is Telling You

A popping or rumbling sound from the tank is almost always sediment. Water gets trapped under the mineral layer, boils into steam bubbles against the hot tank bottom, and the bubbles burst their way up through the crust. On an electric heater the same buildup can bury the lower element and make a crackling or hissing sound.

The noise itself is not dangerous, but it is a clear sign the tank is overdue. Flush it soon. If the popping is loud, has gone on for a year or more, or you also see rusty hot water, a flush may stir up more than it clears, and that is a good time to have a plumber look first.

Step by Step: Draining Sediment From a Tank Heater

You need a garden hose, a flat-head screwdriver or wrench for the drain valve, and somewhere for the water to go: a floor drain, a driveway, or a utility sink lower than the valve. Set aside about an hour. Then work through it in this order:

• Turn off the heat source. On a gas unit, set the control to Pilot or Off. On an electric unit, switch off the breaker. Never let an electric heater power up with the tank empty, or the elements burn out in seconds.
• Close the cold water supply valve on the pipe feeding the top of the tank.
• Let the water cool for an hour or two if you can. Tank water is hot enough to scald.
• Connect the hose to the drain valve near the bottom of the tank and run it to your drain point.
• Open a hot water faucet somewhere in the house so air can enter and the tank drains freely.
• Open the drain valve and let the tank empty. Expect cloudy or gritty water at first.
• Once it is empty, open the cold supply for a few seconds at a time to stir and rinse the bottom. Repeat until the water from the hose runs clear.
• Close the drain valve, remove the hose, and open the cold supply fully. Leave the hot faucet open until it runs without sputtering, which means the tank is full.
• Restore the gas or flip the breaker back on, and check the drain valve for drips over the next day.

How Often Hampton Roads Homes Should Drain Their Tank

Once a year is the right schedule for most homes on city water in Portsmouth, Norfolk, Chesapeake, and Virginia Beach. If you are on a private well in Suffolk, Isle of Wight, or the rural parts of Chesapeake, the water usually carries more minerals and every six months is safer. A large household that runs the heater hard all day also benefits from the shorter interval.

If you see white flakes in faucet aerators or scale building on shower heads, your water is hard enough that the tank is collecting it too. A whole-house water filtration system or softener cuts down how much reaches the heater in the first place, and it can stretch the time between flushes.

Tankless units are a different job. They have no tank to drain, but scale builds up inside the heat exchanger the same way. Those need a descaling flush, usually once a year, where a pump circulates a vinegar or descaling solution through the unit for about an hour using the service valves. If you have one, our tankless water heater service can handle it with the annual inspection.

When to Skip the Flush and Call a Plumber

Flushing is not always the right call, and we would rather say so up front. A tank that has never been flushed in eight or ten years can have sediment packed hard enough to clog the drain valve. Sometimes the old plastic valve cracks or will not close again once it is opened, and now you have a leak you cannot stop.

Call before you start if any of these apply:

• The heater is more than 10 years old and has never been drained
• There is water pooling under the tank or rust around the base
• The hot water comes out brown or smells like rotten eggs
• The drain valve is plastic and already weeps or is hard to turn
• You smell gas anywhere near the unit. Leave the house and call the gas company first

Getting the Tank Serviced by a Licensed Plumber

A professional visit covers more than draining. We flush the tank, test the temperature and pressure relief valve, check the anode rod that keeps the tank from rusting through, inspect the gas venting or electrical connections, and tell you honestly how much life the heater has left. If the answer is not much, our post on the signs you need a new water heater explains what to weigh before spending money on another repair.

When something is already wrong, from no hot water to a leaking tank, our water heater repair service covers tank and tankless units across Hampton Roads. Newman's Plumbing is family owned, backs every job with a 100 percent workmanship guarantee, and answers 24/7. Call (757) 465-0883 to book a flush or ask a question before you open that valve.