Cold Water Supply:

The process begins when cold water enters the tank through a dip tube. This tube directs the water to the bottom of the tank, ensuring that the hottest water remains near the top for immediate use.

Thermostat Activation:

Inside the water heater, a thermostat constantly monitors the water temperature. If it falls below the set level (usually between 120°F and 140°F), the thermostat signals the gas control valve to open.

Ignition of the Gas Burner:

Once the gas control valve opens, gas flows to the burner located beneath the tank. At the same time, the pilot light or electronic igniter ignites the burner. The burner heats the water from the bottom of the tank, causing the water to rise as it heats up.

Heating the Water:

The burner continues to heat the water in the tank until the thermostat detects that it has reached the desired Temperature. The heat exchanger in some models facilitates this process, ensuring efficient heat transfer.

Exhaust and Venting:

As the gas burns, it produces combustion gases like carbon dioxide. These gases are vented out of the home through a flue pipe to ensure the water heater operates safely. Many newer models are equipped with a power vent system to assist with proper ventilation, especially in homes with insufficient natural draft.

Hot Water Supply:

Once the water is heated, it rises to the top of the tank, ready to be used. When you open a hot water tap, the heated water is drawn from the top of the tank through the hot water outlet.

Pressure and Temperature Relief:

For safety, all residential gas water heaters are equipped with a temperature and pressure relief valve (T&P valve). If the tank pressure or temperature becomes too high, the T&P valve releases water to prevent damage or explosions.

Maintaining Water Temperature:

After the water is heated and drawn for use, the thermostat continues to monitor the Temperature. If it falls below the desired setting, the burner reignites to maintain a constant hot water supply.