| 摘要 |
PURPOSE:To reduce power consumed and a noise due to a pump drive by lowering a pump driving torque upon ordinary driving of the space heater. CONSTITUTION:When an operating switch 15 is turned ON, a pump 12 is started at a high torque by a condenser A.16 and a condenser B.17. Then, a gas is burnt, and hot water which has been heated by a heat exchanger 6 flows toward a loader outside the heater. Hot water which has been cooled after executing a work (space heating) passes a temperature switch 9 via a hot water return port 8 and flows again from an expansion tank to the heat exchanger 6 to form a hot water circulating circuit. Then, when the temperature switch 9 detects that the temperature of return hot water has reached a value of 50 deg.C or more, and opens an electric circuit, the space heater is changed over to a low torque driving mode using only the condenser A.16. In a case where the torque is short, the flow quantity of hot water is decreased, and hot water is put into an excessively cooled state, that is, a temperature of 50 deg.C or less, the condenser B.17 operates and carries out a high torque driving and is used without any trouble. |
