PURPOSE: To prevent a circulating pump from being locked by a method wherein the hot water circulating pump for heating is repeatedly brought into operation.
CONSTITUTION: A twin furnace-water system type instantaneous gas hot water supply and heating equipment 1 has a circulating pump 13 and a heat exchanger 9 connected to a heating radiator 3 and a heat exchanger 4 connected to a hot water tap 2, both of which are heated by burners 10 and 5 respectively. The circulating pump 13 is controlled by a heating controlling circuit 12 and at the same time connected to a flow switch 8 of hot water supply side in parallel to a heating switch so as to drive the circulating pump 13 even under the condition that heating is out of operation in order to prevent the pump 13 from being locked.
HORII HIROSHI
ADACHI YOSHIYUKI
HAMADA KAZUTAKA
