Types

The fuel for gas water heaters is typically either propane or natural gas. You will find vent pipe on these units that releases the exhaust from the fuel burning.

Composition

The top of the tank houses the water supply and water delivery pipes. There is also a temperature-and-pressure relief valve (T&P valve) that opens if either the temperature or pressure exceeds the safe zone. The tanks have insulation to keep the water hot.

Function

When you open a hot water tap, the cold water supply line pushes water through the supply pipe into the bottom of the tank. The pressure of water entering the tank pushes hot water out of the top through the delivery pipe and to the tap.

Significance

Gas water heaters have a burner at the base. A control valve and thermostat switch feed gas to the burner, and there is a small flame burning under the tank of water to heat it.

Considerations

The T&P valve should not flow into a drain. The Popular Mechanics website recommends placing a bucket or other storage container under the pipe connected to the valve. That way, if the valve opens, which is a sign that your water heater may not be working right, you know about it.

Source:

Popular Mechanics

Acme How To