What is a Gas Water Heater?


A gas water heater is a type of water heater that is powered by either propane or natural gas. These gas water heaters are typically inexpensive to run, but do cost a bit more than electrical heaters in terms of initial cost.

How does a gas water heater work?

Gas water heaters consist of a few different parts that all work together:

  • Draft hood – Enables air to be drawn into the vent of the water heater ensure pressure is relieved at the gas burner.
  • Vent – Allows exhaust gas to be transferred from inside the water heater to outside your home or commercial property.
  • Tank – This is where the water is held and heated.
  • Cold water inlet pipe – This is a pipe that provides the source of water to be heated.
  • Hot water outlet – This is where hot water leaves the tank to be used for your faucets.
  • Dip tube – Dip tubes ensure cold water from the inlet pipe is going to the bottom of the tank so that hot water remains readily available at the top of the tank.
  • Gas burner – This is what heats up the water inside of the tank.
  • Pressure relief valve – These valves release water in order to lower the pressure inside the tank. This is to prevent the temperature and pressure from your water heater from getting too high.
  • Anode rod – Used to prevent corrosion and rust from affecting the inside walls of the water heater.
  • Thermostat – Enables you to see and adjust the temperature of the water.
  • Thermocouple – A sensor that measures what the current water temperature in the water heater is.

To put it simply, cold water is drawn in from the cold water inlet pipe into the bottom of the water heater tank. As the water sits in the tank, the gas burner continuously ensures the water is at the temperature set by the thermostat. Once someone uses a hot water tap, water is then drawn from the hot water outlet into your sink or shower.

Gas water heaters can also come with a storage tank or be tankless.

How long do gas water heaters last?

Gas water heaters will need to be replaced every 8-10 years. However, your gas heater will require evaluations every 3-5 years from a plumber or professional to ensure the anode rods do not need to be replaced.

How much does it cost to run a gas hot water heater?

The cost to run a gas hot water heater will vary on a few different factors that include:

  • How many gallons of water is used a day on average
  • Number of water heaters
  • Energy cost

On average, expect to pay around $50 a month for your water heater. To calculate what your cost may be, check out the energy calculator provided by EERE here.

Are gas water heaters safe?

Gas waters are safe when they are handled and maintained properly. However, if they are not looked after or are misused, gas water heaters can cause significant damage to your property.

Are gas water heaters easy to install?

Gas water heaters do take a bit of skill to install, but can be quickly learned. Storage tank water heaters will likely require at least two people to be able to move and handle the gas water heater due to how heavy it is.

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