How a Hot Water Heater Works

Our expert Arizona plumbers are at your service to give you the breakdown on water heaters. Ever wondered why the water suddenly gets cold in the middle of your shower when three people have showered before you? Or why the water comes out icy at first when you go to wash your hands? Arizona emergency plumbers have all the answers.

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The parts of a basic water heater are as follows.

  • Tank: The tank is that large outer shell of the water heater. Tanks tend to hold between 40 and 60 gallons of water. There are two types of tanks: fuel-fired and electric. Both types’ exteriors are covered with some sort of insulating material such as a poly urethane foam. Covering those layers tend to be an insulating blanket and then a decorative exterior to make the tank more aesthetically pleasing. Whereas a fuel-fired tank has a vent at the top to remove exhaust gas, an electric tank simply has a cable to connect the heater to the electric panel.


  • Heat-Out Pipe: This is the part of the system that allows the hot water to leave the tanks


  • Dip Tube: This is the conduit for cold water to enter that tank and sink to the bottom where it is then heated.


  • Shut-off Valve: Located outside, the heating unit, the shut-off valve stops the flow of water into the unit


  • Pressure Relief Valve: The pressure relief valve is a safety unit that keeps the pressure inside the tank around 50 to 100 pounds per square inch


  • Thermostat: Plain and simple, the thermostat is the thermometer for the unit

Most households have the type of heater described above, but some newer heaters are tank-less units. In a tank-less heating system, one end of the water supply has a coil of pipe connected and the other is connected to the hot-water delivery piping. The boiler then heats the water and the water heats the coil, which then heats the water.

We know that having your shower water turn ice cold in the middle of a hot relaxation session can be infuriating. If you want more information or tips on how the water heater in your home works, feel free to contact one of Chas Roberts’ Arizona plumbers today! For more information about water heaters or plumbing in general, visit and visit our blog!