What typically controls the on-off function of a gas-fired hot water tank?

The on-off function of a gas-fired hot water tank is typically controlled by a thermostat. This device is essential for maintaining the desired water temperature within the tank. When the water temperature drops below a preset level, the thermostat activates the gas burner to heat the water until it reaches the set temperature. Once the desired temperature is achieved, the thermostat turns off the burner to prevent overheating.

This operation ensures energy efficiency as it only heats water when necessary. By relying on a thermostat, the system can adjust heating cycles based on actual water temperature, helping to provide a consistent supply of hot water while minimizing fuel consumption.