Water Heaters

Fundamentally, a water heater is an appliance that converts energy to heat and transfers that warmth to water. It's connected to a cold water supply pipe and has an outgoing hot water pipe-or system of pipes-that supplies heated water to one or more taps and appliances. A conventional water heater stores heated water in a cylindrical tank. The less-common tankless water heater doesn't store water-it routes heated water straight to taps or appliances.

The majority of water heaters are fueled by natural gas, though propane and electric water heaters are not unusual. Where natural gas is available, it is a much less expensive heat source than electricity.

Small "instant hot-water dispensers" are simply miniature electric water heaters that serve only one faucet. They have a small, under-sink tank that heats and holds nearly-boiling (about 190-degree) water and delivers it under low pressure through a separate sink-top spout.

A conventional gas-fueled water heater warms water with a burner beneath the tank. Natural gas (or propane or kerosene, in some cases) is piped to a gas valve. A thermostat detects the temperature of water in the tank regulates fuel delivery to the burner, which is ignited by a pilot light or spark ignition. A vent collects toxic emissions from the burner and pipes them up through the tank, out the top and normally up through the roof. Some newer, high-efficiency water heaters have fan-assisted vents that can be piped out through a wall.

A heavy electrical cable delivers energy to heating elements in an electric water heater. Electric water heater doesn't create combustion gasses, so no vent is required. They typically have one 5500-watt or, for faster heating, two 4500-watt elements. Separate thermostats control each element, cycling on as needed.





A tankless water heater circulates water through a series of burners or electric coils when you turn on a hot water faucet or appliance. Because the water heater doesn't store hot water, it costs less to operate and doesn't run out of hot water unless the flow exceeds its heating ability. Capacity is measured by how many degrees it increases water temperature at a given flow rate, typically expressed in gallons per minute (gpm).

MORE ABOUT:
/ Water service / / Water valves / / Drain, waste & vent plumbing /
/ Kitchen plumbing / / Kitchen sink plumbing / / Kitchen sinks / / Faucets /
/ Bathroom plumbing / / Bathroom sinks & lavatories /
/ Bathroom sink plumbing / / Bathtubs & showers / / Toilets / / Water heaters /

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