Understanding How Your Water Heater Works

Most of us give little thought to how our water heater actually works. A basic understanding can help you make better decisions when you need to have it repaired or replaced.

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The tank

The tank stores the heated water so it is ready for use. Insulation is incorporated into the design to keep water warm between heating cycles. Most water heater tanks are made of steel lined with glass, to help prevent corrosion. Additionally, a magnesium anode rod inside attracts corrosion away from the tank itself.

The pipes

A supply pipe brings cold water into the tank, routing it to the bottom through a dip tube. The hot-water delivery pipe draws the heated water from the top of the tank and carries it to the rest of the house.

The thermostat and relief valve

The thermostat controls the temperature of the water. Most manufacturers recommend a temperature setting between 120 and 140 degrees Fahrenheit. This is hot enough for showering, doing dishes, and washing clothes, etc., without posing a scalding risk. In homes with small children, the thermostat should stay closer to the lower end of the range.

All water heaters are equipped with a temperature-and-pressure relief valve. If the temperature or pressure of the water exceeds a safe limit, the valve opens allowing water to drain from the tank through a pipe on the outside.

How long will it last?

A water heater typically lasts about 10 years. The build up of minerals, the degradation of the magnesium anode rod, and the eventual rusting of the tank all contribute to its wear. At the end of this time, the heater will likely need to be replaced. This can be done without affecting access to the cold-water supply. The tank is emptied through the bottom and a valve on the supply pipe can shut down only the hot-water plumbing.

Signs of trouble

• A spike in energy bills could mean your water heater is no longer operating efficiently, requiring more energy to heat your water.
• Frequent cycling on and off, or a constant whistling inside the heater, could signal a pressure issue that should be evaluated by a professional.
• Rust-colored flecks of metal indicate that the anode rod has degraded and needs to be replaced.
• Sediment build-up from your water supply. This should be flushed periodically to keep your tank clean on the inside.
• No hot water, hot water that runs out too soon, or water that heats intermittently could all be a failure of the thermostat, the heating element or other issues.

Contact IAQ today to troubleshoot your water heater issues or concerns!