METHOD OF CONTROLLING SHIFT AND COMBUSTION OF THREE-WAY VALVE WHEN SWITCHING TO HEATING IN GAS BOILER FOR BOTH HEATING AND HOT WATER SUPPLY

摘要

PURPOSE: A method is provided to determine the fire extinguishing by using two thermistors for the repeated use of hot water and to switch a three-way valve. CONSTITUTION: A method comprises the steps of: turning on to drive a hot water supply and heating mode; turning on a flow switch; switching a three-way valve to a hot water supply; outputting an answer signal for the confirmation of the switching; driving in a hot water supply mode; turning off the flow switch; deciding if a thermistor(1) is over or the same as a certain temperature(Aset); detecting the difference of temperature between the thermistor(1) and another thermistor(2); deciding if the temperature difference is kept in a certain temperature(B) for a certain time(X); maintaining the three-way valve to the hot water supply without switching to a heating while starting a fire extinguishing driving until the temperature becomes a certain temperature; deciding if the temperature difference is lower or the same as the certain temperature for a certain time(Y); detecting if the flow switch is turned on; switching the three-way valve to the heating if the temperature difference is lower or the same as the certain temperature; outputting an answer signal for the confirmation of the switching; and performing a heating driving.