TWI598552B

The present invention relates to an automatic temperature control system of a gas-burning water heater. Different from the prior art techniques that realizes water temperature control by means of temperature transducer, the system provides a precise control of temperature rise based on detection of water flow rate and the way of rising temperature selected by users. The system comprises a water flow sensor for detecting water flow rate, a heat exchanger for heating and increasing temperature of a water flow, a gas ratio regulation valve for supplying fuel gas to the heat exchanger, a variable potentiometer for allowing users to select temperature rise, and a control unit for receiving the selected temperature rise and the water flow rate and, after calculation, controlling an opening degree of the gas ratio regulation valve. The control unit allows an amount of fuel gas supplied from the gas ratio regulation valve to the heat exchanger to heat the water flow to a selected temperature increase value specified