How and Why to Clean Your Hot Water Heater
Courtesy of John Swygert, Home Inspectors of Middle Tennessee LLC
December 2014, monthly tip e-blast distribution
There are millions of traditional gas and electric hot water heaters in residential homes and there are regular maintenance tasks that can be performed that will help prolong the life and lower the energy costs associated with water heaters.
Water heaters should be flushed periodically to eliminate mineral deposits that can accumulate on the bottom of the tank. One symptom of mineral sediment in the bottom of standard gas water heaters is the sound given off by the overheating of water that is trapped in sediment. The overheated water will flash to steam bubbles that are released into the cooler water and they rapidly collapse as the steam condenses, creating the noise. Electric elements in electric water heaters also signal the presence of mineral buildup by making a hissing or sizzling sound. In each case, removing the mineral buildup will quiet the tank.
Flush sediment from water heaters every six months, or according to the manufacturer’s instructions. If a lot of sediment is seen during the flushing, increase the frequency. If little or no sediment is seen, decrease the frequency of flushing. (Some manufacturers recommend that a few quarts of water be drained from the water heater’s tank every month to clean the tank of deposits.)
Flushing is performed by first turning off the power or gas to the water heater. If the water heater is electric, turn off power at the electrical panel. If the water heater uses gas, turn the thermostat to the “pilot” setting.
Connect a garden hose to the drain valve at the bottom of the water heater. Place the other end of the garden hose to drain somewhere suitable for the hot water that will come out of it when you open the drain valve, such as a driveway. Keep in mind that the water being drained will be very hot, so take appropriate precautions.
Open the drain valve only after shutting off the cold water supply to the water heater and opening a hot-water faucet at a sink or tub inside the home. Opening a hot-water faucet will prevent a vacuum from forming in the lines.
Draining the tank flushes minerals in the bottom of the tank out through the hose. But before flushing the tank, refer to the manual on the tank to read specific instructions for your particular unit.
Once the water stops flowing out of the far end of the hose, turn the water supply back on for a minute or so to flush out any remaining sediment. When the water runs clear from the end of the hose, close the drain valve and turn off the hot-water faucet in the sink or the tub.
Some tanks may need to be completely full in order to turn the water heater back on. Always read the warnings and instructions on the tank label and in the owner’s manual.
Simply lowering the water heater temperature can lower your utility bill. For each ten degree temperature reduction, homeowners can save three to five percent in operating costs. A temperature of 120 degrees in generally considered optimal and safe.
Source: John Swygert, Home Inspectors of Middle Tennessee; monthly tip for December 2014