Gas Hot Water Heater Basics
The vast majority of water heaters are powered by gas or electricity. Gas water heaters are the most common, perhaps because they are generally easier to maintain and repair. Understanding the basics of how a gas water heater works can identify many problems. Although the purpose of a water heater is obviously to heat water, it also ensures that a continuous supply of hot water is available for a reasonable time. Many gas water heaters are designed to be energy efficient, but insulating the heater's tank increases the heater's efficiency even more. Gas water heaters should be set at a safe temperature to avoid the risk of burns. Does this Spark an idea?
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How a Gas Water Heater Works
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At the top of the water heater are two large pipes, one for cold water and one for hot. Cold water enters the tank through the pipe on top and fills the tank. The control box on the front of the heater maintains a pilot flame, which ignites the heater's main burner when the water temperature in the tank falls below the temperature set by the control box. A flue pipe runs vertically through the center of the tank, exiting the top of the tank. This flue pipe transfers the heat from the gas to the water. The draft hood, located on top of the flue tank, allows air to enter the flue and feed oxygen to the burner. Once the water is heated, it exits the hot water pipe at the top of the tank.
Tank Capacity
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Water heaters come in many sizes. Generally, the larger the tank, the more expensive the unit. Also, the larger the tank, the longer the continuous supply of hot water will be available. For most uses, a hot water heater that has a tank capacity of 40 gallons is sufficient. A larger tank should only be considered if a large amount of hot water is frequently required; for example, if two or more showers are often used simultaneously.
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Improving Efficiency with Insulation
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Because a gas hot water heater produces heat, and because water heaters typically aren't sold already insulated, a lot of energy is lost through the tank. Adding insulation to the exterior of the tank can dramatically increase the heater's efficiency and prolong the supply of hot water available. Insulation can be cut to fit the top of the heater's tank. However, leave the draft diverter valve on top of the tank uncovered. The sides of the water heater also can be wrapped with insulation, but it is a good idea to leave access to the control box. Put tape on the seams of the insulation to maximize is effectiveness.
Common Problems with Gas Water Heaters
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Gas water heaters are fairly durable, but problems can develop. The most common problem area is the thermocouple. The thermocouple holds the gas valve open so gas can reach the heater's burner and pilot. If the pilot light won't stay lit, the problem likely is a defective thermocouple. A gas water heater's efficiency can be substantially diminished if the gas openings become covered with rust. Rust develops when the combustion gases degrade the interior of the tank, causing chips of rusted metal to fall onto the burner. If rust is found on the burner, a professional repairman should be consulted immediately.
Adjusting the Water's Temperature to Avoid Burns
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Water heaters can heat water hot enough to cause severe burns. To avoid them, the thermostat should be adjusted to a maximum of 102 to 125 degrees. The thermostat knob is on top of the control box. Some knobs are marked with temperature settings. To determine the water temperature if the knob is not marked, turn a faucet on and put a thermometer in the stream of water.
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