| 摘要 |
PURPOSE:To reduce heat transferring heat loss and contrive the reduction of running cost without deteriorating the function of the titled device by a method wherein temperature controllers are equipped at the outlet and inlet ports of a heat exchanger and outlet hot-water temperature is reduced than the same temperature upon starting the operation of the device when temperature deviations detected by respective temperature controllers are within a predetermined range in order to reduce the temperature of sending hot-water automatically when heating load is small. CONSTITUTION:An inlet hot-water temperature controller 12 is provided in a hot-water inlet pipe 11. A main controller 16 controls a gas amount controller 3 when a temperature difference between the inlet hot-water temperature controller 12 and an outlet hot-water temperature controller 13, provided in the hot-water outlet pipe 14,has become smaller than 10 deg.C to reduce the hot-water temperature in a hot-water sending pipe 8 by 10-20 deg.C. Hot-water temperatures in a hot-water returning pipe 9 and the inlet hot-water temperature controller 12 are increased gradually to temperatures higher than 60 deg.C and temperature differences between inlet and outlet port of hot-water of respective temperature controllers, which were 20 deg.C initially, a reduced. When the inlet hot-water temperature controller 12 and the outlet hot-water temperature controller 13 detect that the temperature difference has becomes smaller than 10 deg.C, the main controller 16 operates a gas amount controller 3 so as to reduce the hot-water temperature in the hot-water sending pipe 8 by 10-20 deg.C. |
