| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a combustion device having a second heat exchanger for collecting the latent heat capable of preventing the second heat exchanger from being heated in the water stop condition during the freezing preventive operation. <P>SOLUTION: The combustion device includes a high temperature side thermo-sensor 40, a low temperature side thermo-sensor 41, and a thermo-sensor for a header part, which are monitored and when either of them indicates 5°C or less, the freezing preventive operation is started, and a heating circulation pump 23 is started, and at the same time, a thermally actuating valve at the heating terminal is opened. As a result, a heating medium flows to the first and second heat exchangers via the heating terminal. Then a bath thermally actuating valve 21 is opened. As a result, the heating medium circulates to the first and second heat exchangers via the primary side of a third heat exchanger. <P>COPYRIGHT: (C)2004,JPO |
