| 摘要 |
<p>PURPOSE:To extend the life of a hot water boiler by reducing the variation of hot water temperature at the time of hot water supply operation, and expanding the ON-OFF cycle at the time of heating operation by providing a control means which increases the temperature difference for ON-OFF switching when a set value for the hot water thermostat is high, and decreases the temperature difference when the set value is low. CONSTITUTION:At the time of hot water supply operation, since the temperature of a hot water to be used is low, the OFF value (set value) for a hot water thermostat is set to be low. Therefore, the temperature which is converted by a hot water temperature converting means 3 by detecting the temperature of the hot water by a temperature detector 2 is lower than the temperature which is set by a hot water temperature setting means 4, and so, the temperature difference for ON-OFF of a hot water thermostat is set to be, e.g. approximate 1 deg.C by a hot water thermostat ON-OFF temperature difference control means 7. Therefore, the variation of hot water temperature at the time of hot water supply operation can be reduced. At the time of heating operation, since the temperature of the hot water to be used is high, the OFF value (set value) for the hot water thermostat is set to be high.</p> |
