| 摘要 |
PURPOSE:To prevent boiling in the heat exchanger section and also prevent the generation of noises of boiling by controlling a burner to a capability which is lower than its max. capability by a specified value when the operation of a heat generator for low temperature is started during the operation of a heat radiator for high temperature. CONSTITUTION:A heat exchanger 3 constitutes part of a hot water circuit 13 which connects successively a coil 11 for additional burning of a bath tub 9, header 12, expansion tank 7, and circulation pump 6. On the downstream side of the circulation pump 6 a low temperature water circulation circuit 15 is branched off and a panel 16 used for floor heating which becomes a radiator for low temperature is connected, and the low temperature header 14 has a thermally actuating valve 18 mounted on it. When a control circuit 29 detects the operation for starting, it heats and controls the circulation water. During the operation of additional burning for the bath tub water 10 or duing the operation of the low temperature circulation circuit 15, if the load of another low temperature water circulation circuit 15 is added for operation, the thermal power of a gas burner 4 is limited to 70%, for instance, of rated maximum capability by a control circuit 29. When a specified time has elapsed, the limitation of thermal power is released and the operation continues. With this arrangement there is no noises of boiling even if the volume of the circulating water to the heat exchanger 3 is reduced by the addition of load of a lop temperature water circulation circuit 15. |
