WARM WATER ROOM HEATER

PURPOSE:To obtain a room heater in which opening of a hole of a heat exchanger is sensed. CONSTITUTION:A user side heat exchanger 7 containing a heat radiating side heat exchanger 5 of a circulating circuit 1 connected with a circulation pump 3 and a heat source side heat exchanger 2 is arranged in a second circulating circuit having a second circulation pump 9 and a radiator 10 piped from a warm water tank 6, and a water level sensor 16 is mounted at the intermediate between upper and lower overflowing ports 15 and 14 of a drain tank 13 connected through a pressure regulating valve 11 of the tank 6. Water flowing from a heat source circuit due to an opening trouble of a hole of the exchanger 5 is retained in the tank 13 through the tank 6, and a water level of the tank 13 is sensed to generate an alarm.