Space and water heating apparatus

Abstract

To detect an abnormality without a limit switch, a space and water heating apparatus includes external and internal circulation channels, including a shared portion, to respectively circulate a heating medium through space heating equipment (20) and a water-heating heat exchanger (28), a first temperature sensor (25) that detects a temperature of the heating medium heated in the shared portion, and a second temperature sensor (35) that detects a temperature of hot water produced with the heat exchanger. A switch controller (40) controls a circulation switcher (29) to switch between the circulation channels. A storage (40a) prestores, in association with a mode of the circulation switcher, a detection value from the second temperature sensor expected when the circulation switcher operates normally. An abnormality detector (40) detects an abnormality in the circulation switcher in response to the actual detection value being different from the expected detection value associated with the instructed mode.

1 . A space and water heating apparatus for performing a space heating operation and a water heating operation, the space heating operation being an operation in which a heating medium is circulated through space heating equipment for space heating, the water heating operation being an operation in which the heating medium circulated in the space heating operation is circulated through a water-heating heat exchanger to heat, by heat exchange with the heating medium, water supplied to the water-heating heat exchanger to produce hot water, the space and water heating apparatus comprising:
 an external circulation channel configured to circulate the heating medium through the space heating equipment;   an internal circulation channel configured to circulate the heating medium through the water-heating heat exchanger, the internal circulation channel including a shared portion shared with the external circulation channel;   a circulation pump in the shared portion, the circulation pump being configured to pump the heating medium in a predetermined direction;   a heater in the shared portion, the heater being configured to heat the heating medium;   a first temperature sensor downstream from the heater in the shared portion, the first temperature sensor being configured to detect a temperature of the heating medium heated by the heater;   a circulation switcher configured to switch between a space-heating circulation mode in which the heating medium is circulated along the external circulation channel and a water-heating circulation mode in which the heating medium is circulated along the internal circulation channel;   a switch controller configured to control switching performed by the circulation switcher;   a second temperature sensor configured to detect a temperature of the hot water produced with heat from the water-heating heat exchanger;   a storage configured to prestore an expected detection value associated with a switching mode of the circulation switcher, the expected detection value being a detection value from the second temperature sensor expected when the circulation switcher operates normally; and   an abnormality detector configured to detect an abnormality in the circulation switcher in response to the detection value from the second temperature sensor being different from the expected detection value associated with the switching mode of the circulation switcher indicated by an instruction from the switch controller.   
     
     
         2 . The space and water heating apparatus according to  claim 1 , wherein
 the expected detection value associated with the space-heating circulation mode is less than a predetermined threshold, and   when an instruction from the switch controller indicates the space-heating circulation mode, the abnormality detector detects an abnormality in the circulation switcher in response to the detection value from the second temperature sensor being greater than or equal to the threshold.   
     
     
         3 . The space and water heating apparatus according to  claim 2 , wherein
 the threshold differs based on an initial detection value and is greater for a greater initial detection value, and the initial detection value is the detection value from the second temperature sensor detected at a time at which an instruction from the switch controller indicating the space-heating circulation mode is provided.   
     
     
         4 . The space and water heating apparatus according to  claim 1 , wherein
 the storage stores a temporal change in the expected detection value,   a rate of increase being the temporal change in the expected detection value associated with the space-heating circulation mode within a predetermined period is less than a predetermined rate of increase, and   when the detection value from the second temperature sensor is less than a predetermined value at a time at which an instruction from the switch controller indicating the space-heating circulation mode is provided, the abnormality detector detects an abnormality in the circulation switcher in response to the detection value from the second temperature sensor having a rate of increase greater than or equal to the predetermined rate of increase within the predetermined period.   
     
     
         5 . The space and water heating apparatus according to  claim 1 , wherein
 when an instruction from the switch controller indicates the water-heating circulation mode and a detection value from the first temperature sensor is greater than or equal to a reference value, the expected detection value associated with the water-heating circulation mode is greater than or equal to a determination value after a wait time elapsed from a time at which the instruction is provided, and   when an instruction from the switch controller indicates the water-heating circulation mode and the detection value from the first temperature sensor is greater than or equal to the reference value, the abnormality detector detects an abnormality in the circulation switcher in response to the detection value from the second temperature sensor being less than the determination value after the wait time elapsed from a time at which the instruction is provided.