Percolating Sounds in Water Heaters

Mineral Deposits

• Minerals occur naturally in water, whether from a well or a municipal system. Most of the time, you can’t see the minerals since they are dissolved in the water. But the heating cycle inside a water heater causes some of the mineral deposits to cling together. After the water cools, mineral deposits sink to the bottom of the tank, then pop back up again when the unit calls for more heat. On electric water heaters, these deposits cake the elements, sometimes causing them to burn out.

Flushing the Tank

• You can remove sediment from the water heater by draining the tank and flushing out the deposits. Turn off the gas, oil or electricity to the tank first, then turn off the cold water supply. Attach a hose to the drain at the bottom of the tank, and open the valve. The water coming out the end of the hose will look milky white, and a few small chunks of mineral deposits might flow out as well. Open up a hot water tap near the tank, which will aid in flushing out the system. Be sure you let the water heater cool for a couple of hours before opening up the valve. The water inside is at least 120 degrees Fahrenheit.

Water Softener

• Consider adding a water softener system if your water has a lot of minerals dissolved within. Water softeners cut down on the amount of minerals in water by filtering them out. Installing one is a big job probably best left up to a licensed plumber. Maintain one after it’s installed by adding the recommended amount of water softening salt to the tank.

Pressure-Relief Valve

• If the percolating sounds turn into more of a boiling noise, you may have a bigger problem. Water heaters have a pressure-relief valve each on the side of the tank, or mounted on top of the unit. This valve’s sole purpose is to allow steam to escape from a water heater that has overheated. If the steam cannot escape, it presents a dangerous situation that could result in injury to people in the home or damage to property. Shut down power or gas to the tank and call a licensed plumber. He can check the valve and replace it if necessary.