Heating water for various applications is the sole function of a water heater. If you understand how water boils in a kettle, you are close to grasping the mode of operation of the water heater. Water heaters have a compartment that contains natural gas to enable the device draw energy from it to heat the water.

The principle on which water heating devices function can be imitated sufficiently by propane or electricity for those options to avail as alternatives for powering the device. Powering a water heater by propane or electricity is however not as economical as powering by natural gas.

With the tank acting as storage, heat is drawn from the burner under the tank and used to warm the water. The design of the water heater is such that gas has to pass through a valve on the wall to get the device to function. Working from inside the tank of the heater, the thermostat is able to control the gas in the heater by linking with the valve and reducing fuel intake.

The burner in a gas water heater is able to heat up because of a spark that is ignited by a pilot light. Using igniter devices on gas grills as a close observation will reveal that it closely resembles the pilot light mechanism of a water heater. A venting system is to a gas water heater what an exhaust pipe is to a car engine.

Gas water heaters have a PVC pipe which is used in the venting system to channel out the toxic emissions from the system. If you knew of the performance enhanced fan-assisted gas water heater, you will probably get one yourself, know it discharges exhaust at a faster rate through the wall. As gas is supplied through the wall via a gas valve, cold water is supplied via a supply pipe that is connected to the heater.

The heated water finds its use in appliances after passing from the storage tank through pipes in the heater and a tap or water valve. It is actually possible for this system to function without a tank, as may be seen in a few different models of the water heater. The network of pipes in this case is the link between a series of burners and the valve that supplies hot water to the faucet or appliance.

The cylindrical tank serves as a major component that causes the difference between the operation of the regular heater and the tankless version. As long as water enters into the system, a tankless water heater will produce an endless output of hot water.

If you are one concerned about how much energy you burn in running household appliances, then a tankless heater is your best bet.

One of the main disadvantages of the tankless heater is the length of time it require to heat water with respect to the regular version that does not have to wait until the faucet is turned on before it begins heating. Holding water is not one of the functions of a tankless heater, as the water only passes through it for heating en route to the now open faucet. Creating the tankless heater obviously was with the view to heat and direct water to appliances.