Maintaining and Fixing Water Heaters

Water heaters are little more than giant insulated water bottles with heaters. As hot water is used, cold water enters through a dip tube. This lowers the water temperature inside the tank, causing a thermostat to call for heat. In gas units, burners beneath the water tank kick in and continue heating the water until the desired temperature is reached. Heating elements perform the same function in electric water heaters. Most water heater problems are the result of sediment buildup or rust. You can help prevent this by opening the drain valve every few months and flushing out a few gallons of water. This purges rust and mineral buildup from the heater.

Vital Numbers - The nameplate on the outside of your water heater gives the unit’s vital statistics. Look for:

■ Tank Capacity: The more gallons it holds, the less chance you’ll run out of hot water during a shower. A 40-gallon tank suits most households.

■ R-Value: The better insulated the unit is, the more efficient it will be. If yours has an R-value of less than 7, wrap the tank with insulation.

■ Installation Clearances: This tells you how much room you must leave between the unit and any combustible materials.

Water Heater Repair Chart




No hot water.

No power to the heater (electric). Pilot light out (gas).

Check circuit breaker or fuse (electric). Relight pilot; replace thermocouple if pilot does not stay lit.

Water not hot enough.

Upper element burned out (electric).

Replace upper element.

Not enough hot water—hot water runs out quickly.

Thermostat set too low.

Plot water must travel a long way to get to faucets.

Sediment buildup in tank.

Lower element burned out (electric). Burner blocked by dirt (gas).

Leaking faucets.

Tank not large enough for demand.

Turn thermostat up.

Insulate hot water pipes.

Drain and refill tank.

Replace lower element.

Clean burner, or call gas company. Repair faucets.

Replace with a larger tank.

Tank makes noise.

Sediment in tank.

Drain and refill tank.

Leak from temperature-and-pressure-relief valve.

Thermostat set too high.

Defective temperature-and-pressure-relief valve.

Lower thermostat setting. Replace valve.

Leak around tank base.

Tank corrosion has created a leak.

Replace water heater.

Replace a leaking drain valve. If your water heater’s drain valve leaks, shut off the cold water stop valve, shut off the gas or the electrical current, and drain the water heater. Unscrew the faulty valve. Apply Teflon tape or pipe joint compound to the male threads of a new valve, and install. Fill tank, and restore power or gas.

Test a relief valve. Either on top or high on the side of the water heater, you’ll find a relief valve that opens if the temperature or pressure in the tank gets too high (thus, it is called a “T-and-P-relief valve”). Test it once a year by pulling on the handle; water should rush out of the pipe it is attached to.

Replace a faulty relief valve. If no water comes out, replace the valve. Shut off the cold water, turn off power or gas to the unit, and drain some of the water. Remove the attached drainpipe and the valve. Apply Teflon tape or pipe joint compound to the male threads when you install the new valve.

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