Why Does My Water Heater Make a Knocking Noise?

Don’t be alarmed if you hear knocking or popping from your basement. The most likely cause is your hot water heater. Over time, the sediment in your water can harden into what our plumbers call “scale.”

If enough scale builds up in the tank, it can reduce your water heater’s energy efficiency and lifespan. Continue reading to learn why your water heater makes a knocking noise. Our Michigan, Indiana, Ohio & Florida plumbers also offer water heater maintenance so you can avoid early replacement.

We recommend you flush your water heater at least once a year. If you can’t remember the last time you flushed the water heater, call our plumbers today. Our plumbing contractors will be able to perform water heater maintenance for your peace of mind. Scheduling water heater maintenance helps you save money in the long run by helping you avoid expensive repairs.

Why Does My Water Heater Make Strange Noises?

Hard water contains minerals that are safe for humans, but wreak havoc on your hot water heater. Over time, these minerals settle on the bottom of your hot water tank. When you use your water heater, the high temperatures harden minerals into scale and trap pockets of water. Eventually this trapped water turns into steam and breaks through layers of scale to create a popping or knocking sound.

How Do I Flush My Water Heater?

If you don’t feel comfortable flushing your water heater on your own, call one of our plumbers to schedule water heater maintenance. One of our plumbers will come out to your home to flush your hot water heater so you don’t have to worry about sediment buildup for another year.

While you can flush a water heater on your own, we recommend hiring one of our plumbers if it’s been a few years. If you’ve scheduled water heater service regularly and think you want to DIY this year, follow our instructions below.

You will need:

• Turn off fuel or electrical power.

  Whenever you do repairs to your hot water heater, you will always need to shut off its power source. Depending on whether you have a gas or electric water heater, you will need to shut off the fuel or electrical power. Be sure to follow the manufacturer’s instructions.

• Turn off cold water supply.

  Near the top of your hot water heater should be two valves. One is responsible for feeding in cool water and the other for sending out heated water. The valve you want should be clearly marked blue for cold water supply. Turn the valve 90 degrees to shut it off.

  For your safety, we recommend that you wait overnight (or at least 30 minutes) for the water in your tank to cool down. If not drained properly, the scalding water could cause injury.

• Turn on hot water from nearby faucet.

  While draining and flushing the tank, be sure to keep hot water running from a nearby faucet. Not only will this introduce air flow into your hot water heater to ease draining, but it will also prevent a vacuum from forming in your lines.

• Attach a garden hose to drain valve.

  When doing this step, be sure that you are wearing your protective gloves. Also make sure that the other end of the garden hose is placed in a safe area for the water to drain, such as a basement drain or bucket.

• Drain hot water tank.

  When you open the drain valve, dirty water will come out through the hose. Don’t be alarmed. This merely shows that the sediment is being cleared from your hot water tank. Keep going until all the water is drained from the tank.

  The water coming out may be extremely hot, which is why it’s important to wear your protective gloves. If you are using a bucket to drain the water into, you may need to empty your bucket several times during this process.

• Flush hot water tank.

  When there is no more water coming out, you will need to make sure that there is no residual sediment left in the tank. Open and close the cold water supply valve a few times to disturb any residual sediment left on the bottom of the tank. Stop once the water comes out completely clear.

• Close tank drain valve.

  Once you are done flushing your hot water heater, disconnect the hose, and close the tank drain valve. Also, make sure you shut off the hot water faucet you turned on earlier.

• Fill hot water tank.

  Open the cold water supply valve to fill the water heater tank back up. To make sure there are no air bubbles in your lines, we recommend running all the hot water faucets in your home until normal water pressure returns.

• Turn power back on.

  Once the tank is completely filled, relight your water heater by following the manufacturer’s instructions. Congratulations, your water heater is set for another year!

Our Michigan, Indiana, Ohio & Florida water heater plumbers work hard to earn your business. Whether you need your hot water heater flushed or an emergency water heater repair, you can trust our years of experience. To request a quote for water heater maintenance, call Whitney Services at (877) 393-2141.