| 摘要 |
PROBLEM TO BE SOLVED: To eliminate erroneous judgment of a high temperature as a temperature fault of a vaporizer raising immediately after combustion is stopped, by stopping the combustion of a burner and a blower when a warm water temperature arrives at a predetermined temperature, and stopping a vaporizer temperature detecting means for judging a fault if the vaporizer temperature is a predetermined temperature or higher for a predetermined time. SOLUTION: During burning of a combustion unit, a temperature of a vaporizer 15 is sensed, and if the vaporizer 15 is lower than a predetermined temperature T2, it is judged as being normal, its operation is continued, while, if not, the vaporizer 15 is judged to be an abnormally high temperature, and the operation is stopped. If the temperature of the vaporizer is normal, a water temperature T3 sensed by a warm water thermistor 17 is compared with a given temperature T4r stored in a memory. Then, if the temperature T3 is the temperature T4 or higher, an operation of a blower 23 is stopped, and the combustion is stopped. Then, cooling air is not supplied to the vaporizer 15, and a heat of the burner is transferred to the vaporizer 15. Accordingly, the temperature of the vaporizer 15 is instantaneously raised, and temperature sensing of the vaporizer 15 by a thermistor 3 is stopped.
|
