How It Works
Gas water heaters combust natural gas or propane to heat
water for cooking, cleaning, bathing and heating. Cold water enters the bottom
of the water tank. The water rises up and through the tank as a gas burner
heats the water. Exhaust from the gas combustion is vented through the top of
the water heater and then outside the home.
What Can Go Wrong?
If the pilot light goes out or the electrical igniter won’t
fire, there may be a problem with your hot water heater. If you confirm that
gas fuel is properly reaching the water heater, then the problem is likely a
failed thermocouple or electrical igniter. You’ll need to get a repair service
technician to replace it.
Another common problem is caused when sediment (scale)
builds up at the bottom of the water heater tank. The build-up creates problems
with the sacrificial anodes, which are meant to protect from corrosion. In
addition, this may cause the bottom of the tank to overheat and can even melt
away the protective glass lining. Regular preventive maintenance can prevent
Aside from heating and cooling, water heating represents the
greatest consumption of energy in the home, amounting to about 25 percent of
gas usage. The typical household uses 30 to 140 gallons of hot water per day,
while water heating tanks range from 20 to 80 gallons in size. Conventional gas
water heaters use much less energy than electric hot water heaters. A typical
water heater for a household using 100 gallons of hot water per day burns about
38,200 cubic feet of natural gas annually, and produces about 17,500 pounds of
carbon dioxide (CO2).