Gas water heater is a type of water heater that uses gas as the main energy material, and the high-temperature heat generated by gas combustion is transferred to the cold water flowing through the heat exchanger to achieve the purpose of preparing hot water. Gas fired water heaters are the mainstream water heaters that once dominated the water heater market. Their advantages are that they are ready to use, do not need to wait, and occupy a small area, which can save a lot of space for comrades living in cramped homes.

The gas water heater is mainly composed of a valve body assembly, a main burner, a small fire burner, a heat exchanger, a safety device, etc. It also includes the flue of a flue water heater and the forced exhaust device of a forced exhaust water heater. The valve body assembly controls the entire working program of the water heater, including water valves, gas valves, microswitches, and igniters. When installing a water heater, valves should be installed on the inlet, outlet, and gas pipes.