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Johansen & Anderson Inc Blog

What’s That Knocking Sound Coming from the Water Heater?

plumber-hot-water-heaterSometimes, a noise coming from an appliance is a major pain, and it may even alert you to danger in the system. Other times, however, a noise is so faint that it causes little alarm and you feel content to go about your day. A water heater can occasionally make a knocking or popping noise that falls somewhere between these two extremes.

We don’t think any noise from your water heater (or other home system) should be ignored. A knocking noise, especially, can indicate problems that can accelerate the longer you let them go on. We explain what this noise may be and what you should do about it in the guide below.

Probable Source: Scaling

This knocking noise is likely due to mineral deposits, or sediment, that has gathered at the bottom of the tank—also known as scale. The sound is due to the reduced volume in the tank, which forces steam bubbles to rise as the burners heat the tank. The bubbles become trapped and rattle around the sediment at the bottom of the tank, causing this knocking, popping, or rattling noise.

We have found other sources for a noise that could be described as a knocking or popping. Be sure to call in technicians before assuming a cause for your water heater troubles. Scaling can cause major damage to a tank, and may allow for corrosion that means you must replace your tank.

How Scale Enters a Water Heater Tank

Want to know how that scaling enters the tank in the first place? This a result of hard water, an excess of minerals in the water supply. Hard water is not usually harmful for your health, as the minerals involved are ions such as calcium and magnesium, but it can cause some major damage to your pipes and plumbing components.

Deposits get left behind in the bottom of the tank, which is made of metal but lined with a glass lining. The deposits rattling around at the bottom of the tank can wear down this lining, though, and force the tank to corrode. There’s no coming back from this permanent tank damage.

Flushing a Water Heater

Some water heaters are stuck dealing with hard water throughout their lifespans. In this case, you may need regular flushing of your tank to clear out any sediment that has gathered at the bottom of the tank. We recommend letting a technician do this during annual maintenance.

Annual maintenance of a water heater allows for flushing as well as several other tasks that help to protect your water heater. Your technician makes adjustments and looks for signs of wear-and-tear or corrosion so you can schedule the service the system needs.

Treating the Hard Water

You might consider treating the hard water at the source instead of dealing with regularly flushing the water heater tank. This involves installing a water filtration system or, more effectively, a water softener. A water softener replaces the hard water ions with sodium to protect your water heater tank, as well as the plumbing throughout your home.

Johansen & Anderson Inc installs and services water heaters in Joliet, IL. Contact us today!

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