JP2018063100A - Hot air heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of automatically detecting presence/absence of ON-failure of a relay in a hot air heater including a burner and an electric heater.SOLUTION: A hot air heater is disclosed. The hot air heater includes: a housing including an air supply port and a blowout port; a burner for heating the air by burning a fuel; an electric heater for heating the air by converting the electric power to heat; a relay provided on a power supply line to the electric heater, for permitting electric conduction to the electric heater in the case of ON and prohibiting the electric conduction to the electric heater in the case of OFF; a heater temperature sensor for detecting the temperature of the electric heater; a blower fan for taking in the air from indoors via the air supply port, for allowing the air to pass the burner and the electric heater and delivering the air to the indoors via the blowout port; and a control device. In the hot air heater, the control device determines presence/absence of ON-failure of the relay based on a temporal change of the temperature detected by the heater temperature sensor when the relay is controlled to be OFF.SELECTED DRAWING: Figure 3

Description

  The present specification relates to a hot air heater.

  Patent Document 1 discloses a housing having an air inlet and a blowout port, a burner that is housed in the housing, burns fuel, and heats the air, and is housed in the housing to convert electric power into heat. An electric heater that heats the air, and a relay that is provided on a power supply line to the electric heater, and that allows energization of the electric heater when on and prohibits energization of the electric heater when off A hot air fan that is housed in a housing, takes in air from the room through an air supply port, passes through a burner and an electric heater, and sends the air into the room through an air outlet, and a control device A heater is disclosed.

JP-A-5-34010

  In the hot air heater as described above, if the relay is turned on, even if the control device controls the relay to be turned off, the electric heater is energized. There is a risk that a member in the vicinity thereof is overheated and damaged. In a hot air heater equipped with a burner and an electric heater, a technique capable of automatically detecting the presence or absence of a relay on failure is expected.

  In this specification, the technique which solves the said subject is provided. The present specification provides a technique capable of automatically detecting the presence or absence of a relay on failure in a hot air heater including a burner and an electric heater.

  This specification discloses a warm air heater. The warm air heater includes a housing having an air supply opening and an air outlet, a burner that burns fuel to heat air, an electric heater that converts electric power into heat and heats the air, and an electric heater A relay provided on the power supply line that permits energization of the electric heater when on and prohibits energization of the electric heater when off; a heater temperature sensor that detects the temperature of the electric heater; A blower fan that takes in air from the room through the air vent, passes the burner and the electric heater, and sends the air into the room through the air outlet, and a control device are provided. In the hot air heater, the control device determines the presence or absence of an ON failure of the relay based on the change over time of the temperature detected by the heater temperature sensor when the relay is controlled to be turned off.

  When the control device controls the relay to be off, if the relay is operating normally, the electric heater will not generate heat, but if the relay is on-failed (that is, the electric heater is energized). If so, the electric heater generates heat. Therefore, in the hot air heater described above, the control device determines whether the relay is on or not based on the change over time of the temperature detected by the heater temperature sensor when the relay is turned off. . According to the hot air heater described above, when the relay is turned on, it is possible to automatically detect the relay on failure before the electric heater or a member in the vicinity thereof is damaged by overheating.

The figure which shows typically the structure of the gas fan heater 2 which concerns on an Example. The figure which shows typically the electric system of the gas fan heater 2 which concerns on an Example. The flowchart explaining the operation | movement at the time of power activation of the gas fan heater 2 which concerns on an Example. The figure explaining the relationship between the time-dependent change of heater temperature at the time of power activation of the gas fan heater 2 which concerns on an Example, and the presence or absence of an ON failure. The flowchart explaining the operation | movement at the time of completion | finish of the heating operation of the gas fan heater 2 which concerns on an Example. The figure explaining the relationship between the time-dependent change of heater temperature at the time of the heating operation end of the gas fan heater 2 which concerns on an Example, and the presence or absence of an ON failure.

  In one or more embodiments, the hot air heater is a temperature detected by the heater temperature sensor in a state where the control device controls the relay to be turned off when the hot air heater is powered on. It may be configured to determine that the relay is on-failed when the value of is increased.

  When the hot air heater is turned on, the electric heater is at a temperature similar to room temperature. And when the relay is operating normally, the temperature of the electric heater will not rise as long as the control device controls the relay to be off. On the other hand, when the relay is on, the electric heater generates heat and the temperature of the electric heater rises even if the control device controls the relay to be off. Therefore, in the hot air heater described above, whether or not the temperature detected by the heater temperature sensor rises when the control device controls the relay to be turned off when the hot air heater is turned on. If the temperature detected by the heater temperature sensor rises, it is determined that the relay is on. With such a configuration, it is possible to quickly detect an ON failure of the relay.

  In one or more embodiments, the hot air heater is a temperature detected by the heater temperature sensor in a state where the control device controls the relay to be turned off when the heating operation using the electric heater is finished. However, when the predetermined time has not elapsed, the relay may be determined to be on-failed when the temperature does not drop to the predetermined temperature.

  When the heating operation using the electric heater is completed, the electric heater is at a high temperature. When the relay is operating normally, if the control device controls the relay to be turned off, the temperature of the electric heater decreases due to heat dissipation. On the other hand, when the relay is on, the electric heater generates heat and the temperature of the electric heater does not drop so much even if the control device controls the relay to turn off. Therefore, in the hot air heater described above, the temperature detected by the heater temperature sensor in a state where the control device is controlling the relay to be turned off when the heating operation using the electric heater is completed is a predetermined time. It is determined whether or not the temperature falls to a predetermined temperature when the time has elapsed. Then, the control device determines that the relay is on-failed when the temperature detected by the heater temperature sensor does not drop to the predetermined temperature when the predetermined time has elapsed. With such a configuration, it is possible to quickly detect an ON failure of the relay.

(Example)
A gas fan heater 2 according to an embodiment of a hot air heater will be described with reference to FIG. The gas fan heater 2 takes in air from the room through the air supply port 4 on the back surface, burns the fuel gas using the sucked air as combustion air, and converts the air heated by the combustion of the fuel gas into the air outlet 6 on the front surface. The room is heated by sending it into the room. The gas fan heater 2 is a so-called open type gas fan heater.

  The gas fan heater 2 takes in indoor air from a gas supply pipe 8 that supplies fuel gas, a burner 10 that burns fuel gas from the gas supply pipe 8, and an air supply port 4, and blows out the heated air 6, a blower fan 12 that is sent into the room, a control unit 14 that controls the operation of the gas fan heater 2, an operation unit 16 that allows the user to operate the gas fan heater 2, and a housing 18 that houses these. Yes.

  The air supply port 4 is formed on the upper side of the back surface of the housing 18, and the air outlet 6 is formed on the lower side of the front surface of the housing 18. Inside the casing 18, a part of the air flowing in from the air supply port 4 is supplied to the burner 10 as combustion air, and the remaining air is mixed with the combustion exhaust gas of the burner 10 and led to the outlet 6. A passage 20 is formed. The blower fan 12 is disposed downstream of the burner 10 in the internal air passage 20 (between the burner 10 and the outlet 6). The air supply port 4 is provided with an air filter 22 that suppresses entry of dust and the like.

  An electric heater 24 is provided between the blower fan 12 and the outlet 6 in the internal air passage 20. The electric heater 24 generates heat when energized and heats the air passing through the internal air passage 20.

  The gas supply pipe 8 is provided with an electromagnetic on-off valve 26 that opens and closes the gas supply pipe 8. The gas supply pipe 8 is supplied with city gas (for example, gas mainly composed of methane gas (CH 4) such as 13A) from the outside of the gas fan heater 2. The burner 10 is provided with an igniter 28 above the flame opening.

  An indoor temperature sensor 30 is provided on the rear surface of the housing 18. The indoor temperature sensor 30 detects the temperature of indoor air sucked into the housing 18 from the air supply port 4. As the indoor temperature sensor 30, various types such as a thermocouple and a thermistor can be used.

  In the internal air passage 20, a heater temperature sensor 32 is provided in the vicinity of the electric heater 24. The heater temperature sensor 32 detects the temperature of the electric heater 24. As the heater temperature sensor 32, various types such as a thermocouple and a thermistor can be used.

  As shown in FIG. 2, the operation unit 16 sets an operation switch 34 that instructs the user to start and stop the operation of the gas fan heater 2, an abnormality notification buzzer 36 that notifies the user of the occurrence of an abnormality, and a heating target temperature. The temperature setting part 38, the display part 40 which displays various information, such as heating target temperature and room temperature, are provided. The operation switch 34 is configured to alternately instruct the control unit 14 to start and stop operation each time the pressing operation is repeated.

  The control unit 14 controls operations of the blower fan 12, the electric heater 24, the on-off valve 26, the igniter 28, and the like. The control unit 14 includes a memory 42 for storing various programs and data, and a timer 44 for timing.

  The control unit 14 controls energization to the electric heater 24 by switching on / off the first relay 46 and the second relay 48. Each of the first relay 46 and the second relay 48 is provided on a power supply line to the electric heater 24. The first relay 46 and the second relay 48 permit energization of the electric heater 24 when turned on, and supply the electric heater 24 when turned off. Prohibit energization. When both the first relay 46 and the second relay 48 are on, the electric heater 24 is energized. When one or both of the first relay 46 and the second relay 48 are off, the electric heater 24 is energized. Is cut off.

(Operation at power-on)
When the power cord (not shown) of the gas fan heater 2 is plugged into the outlet of the house, the gas fan heater 2 is turned on. When the gas fan heater 2 is powered on, the control unit 14 performs the process shown in FIG. 3 to determine whether or not the first relay 46 and the second relay 48 are on.

  In step S2, the control unit 14 acquires an initial reference heater temperature. In the gas fan heater 2 of the present embodiment, the control unit 14 sets the temperature detected by the heater temperature sensor 32 to the initial reference heater temperature.

  In step S4, the control unit 14 controls the first relay 46 to be on and the second relay 48 to be off. In this case, if the second relay 48 is operating normally, the electric heater 24 is not energized. However, when the on-failure occurs in the second relay 48, the electric heater 24 is energized.

  In step S <b> 6, the control unit 14 starts timing by the timer 44.

  In step S8, the control unit 14 determines whether or not the elapsed time from the start of the time measurement by the timer 44 in step S6 is equal to or longer than a first predetermined time (for example, 60 seconds). If the elapsed time is less than the first predetermined time (NO), the process proceeds to step S10.

  In step S10, the control unit 14 determines that the temperature (heater temperature) detected by the heater temperature sensor 32 is equal to or greater than a value obtained by adding a first predetermined temperature width (for example, 20 ° C.) to the initial reference heater temperature acquired in step S2. Judge whether there is. If the heater temperature is less than the initial reference heater temperature plus the first predetermined temperature range (NO in step S10), the process returns to step S8. If the heater temperature is equal to or higher than the value obtained by adding the first predetermined temperature width to the initial reference heater temperature (YES in step S10), the process proceeds to step S12.

In step S <b> 12, the control unit 14 determines that an ON failure has occurred in the second relay 48, and notifies the user that an ON failure has occurred in the second relay 48 via the operation unit 16. In the process of FIG. 3, step S12 is executed because the first predetermined time (for example, 60 seconds) has elapsed since the first relay 46 was controlled to be turned on and the second relay 48 was turned off in step S6. In this case, the temperature of the electric heater 24 has risen by a first predetermined temperature range (for example, 20 ° C.) or more. As shown in FIG. 4, if the second relay 48 is operating normally, and controls the first relay 46 turned on at time t _1, when controlling turns off the second relay 48, the electric heater 24 is Since no power is supplied, the temperature of the electric heater 24 does not rise as the initial reference heater temperature T ₀ that is the heater temperature immediately after the power is turned on even at time t ₂ after the first predetermined time has elapsed since time t ₁ . In contrast, if the ON failure in the second relay 48 occurs, by controlling the first relay 46 turned on at time t _1, when controlling turns off the second relay 48, it is energized electric heater 24 made The In this case, the temperature of the electric heater 24 is gradually increased with time, from time t ₁ to time t ₂ after the lapse of the first predetermined time, the initial reference heater temperature T ₀ the first predetermined temperature width [Delta] T ₁ Will exceed the temperature. Accordingly, by appropriately setting the first predetermined time and the first predetermined temperature range, it is possible to detect the presence or absence of the on-failure of the second relay 48 by the processing from step S6 to step S12 shown in FIG. it can. After step S <b> 12, the control unit 14 controls the first relay 46 to be turned off and ends the process of FIG. 3.

  If the elapsed time is equal to or longer than the first predetermined time in step S8 (YES), the process proceeds to step S14.

  In step S14, the control unit 14 controls the first relay 46 to be turned off and the second relay 48 to be turned off.

  In step S <b> 16, the control unit 14 starts measuring time by the timer 44.

  In step S18, the control unit 14 waits until the elapsed time after starting the time measurement by the timer 44 in step S16 reaches an interval time (for example, 0.5 seconds). If the elapsed time reaches the interval time (YES), the process proceeds to step S20.

  In step S20, the control unit 14 controls the first relay 46 to be turned off and controls the second relay 48 to be turned on. In this case, if the first relay 46 is operating normally, the electric heater 24 is not energized. However, when the first relay 46 has an on-failure, the electric heater 24 is energized.

  In step S <b> 22, the control unit 14 starts measuring time by the timer 44.

  In step S24, the control unit 14 determines whether or not an elapsed time after starting the time measurement by the timer 44 in step S22 is equal to or longer than a second predetermined time (for example, 60 seconds). If the elapsed time is less than the second predetermined time (in the case of NO), the process proceeds to step S26.

  In step S26, the control unit 14 determines that the temperature detected by the heater temperature sensor 32 (heater temperature) is equal to or greater than a value obtained by adding a second predetermined temperature width (for example, 20 ° C.) to the initial reference heater temperature acquired in step S2. Judge whether there is. If the heater temperature is less than the initial reference heater temperature plus the second predetermined temperature range (NO in step S26), the process returns to step S24. If the heater temperature is equal to or higher than the value obtained by adding the second predetermined temperature width to the initial reference heater temperature (YES in step S26), the process proceeds to step S28.

In step S <b> 28, the control unit 14 determines that an ON failure has occurred in the first relay 46 and notifies the user that an ON failure has occurred in the first relay 46 via the operation unit 16. In the process of FIG. 3, step S28 is executed because a second predetermined time (for example, 60 seconds) has elapsed since the first relay 46 is controlled to be turned off and the second relay 48 is turned on in step S20. This is a case where the temperature of the electric heater 24 has increased by a second predetermined temperature range (for example, 20 ° C.) or more. As shown in FIG. 4, if the first relay 46 is operating normally, the first relay 46 is controlled to be turned off at time t _3, when controlling the second relay 48 ON, the electric heater 24 is Since no power is supplied, the temperature of the electric heater 24 does not rise as the initial reference heater temperature T ₀ that is the heater temperature immediately after the power is turned on even at the time t ₄ after the second predetermined time has elapsed since the time t ₃ . In contrast, if the ON failure in the first relay 46 is occurring, the first relay 46 is controlled to be turned off at time t _3, when controlling the second relay 48 ON, the energization to the electric heater 24 made The In this case, the temperature of the electric heater 24 rises with the passage of time, and the second predetermined temperature width ΔT ₂ from the time t ₃ to the initial reference heater temperature T ₀ by the time t ₄ after the second predetermined time has elapsed. Will exceed the temperature. Accordingly, by appropriately setting the second predetermined time and the second predetermined temperature range, it is possible to detect the presence or absence of an on-failure of the first relay 46 by the processing from step S20 to step S28 shown in FIG. it can. After step S28, the control unit 14 controls the second relay 48 to be turned off, and ends the process of FIG.

  If the elapsed time is equal to or longer than the second predetermined time in step S24 (YES), the process proceeds to step S30.

  In step S30, the control unit 14 controls the first relay 46 to be turned off and the second relay 48 to be turned off. After step S <b> 30, the control unit 14 ends the process of FIG. 3 and waits until the user instructs the start of the heating operation via the operation unit 16.

(Operation at the start of heating operation)
When the user operates the operation switch 34 and the start of the heating operation is instructed, the control unit 14 drives the blower fan 12 to supply combustion air to the burner 10 and opens the on-off valve 26 to gas. Gas is supplied from the supply pipe 8 to the burner 10 and ignited by the igniter 28, whereby combustion of the burner 10 is started. Further, the control unit 14 energizes the electric heater 24 by controlling the first relay 46 to be on and controlling the second relay 48 to be on. Thereby, the gas fan heater 2 takes in air from the room through the air supply port 4, heats it with the burner 10 and the electric heater 24, and then sends the heated air into the room through the air outlet 6. Heat the room.

(Operation at the end of heating operation)
When the user operates the operation switch 34 and is instructed to end the heating operation during the heating operation, the control unit 14 closes the on-off valve 26 to extinguish the burner 10 and performs the processing shown in FIG. To determine whether or not the first relay 46 and the second relay 48 are on.

  In step S32, the control unit 14 drives the blower fan 12 at a predetermined rotational speed (for example, 600 rpm) to start a post-purge operation.

  In step S34, the control unit 14 acquires the first reference heater temperature. In the gas fan heater 2 of the present embodiment, the control unit 14 sets the temperature detected by the heater temperature sensor 32 to the first reference heater temperature.

  In step S36, the control unit 14 controls the first relay 46 to be on and the second relay 48 to be off. In this case, if the second relay 48 is operating normally, the electric heater 24 is not energized. However, when the on-failure occurs in the second relay 48, the electric heater 24 is energized.

  In step S <b> 38, the control unit 14 starts measuring time by the timer 44.

  In step S40, the control unit 14 waits until the elapsed time from the start of the time measurement by the timer 44 in step S38 reaches a third predetermined time (for example, 60 seconds). When the elapsed time reaches the third predetermined time (when it becomes YES), the process proceeds to step S42.

  In step S42, the control unit 14 determines that the temperature detected by the heater temperature sensor 32 (heater temperature) is equal to or less than a value obtained by subtracting a third predetermined temperature range (for example, 15 ° C.) from the first reference heater temperature acquired in step S34. It is determined whether or not. When the heater temperature exceeds a value obtained by subtracting a third predetermined temperature range (for example, 15 ° C.) from the first reference heater temperature (NO in step S42), the process proceeds to step S44.

In step S <b> 44, the control unit 14 determines that an ON failure has occurred in the second relay 48, and notifies the user that an ON failure has occurred in the second relay 48 via the operation unit 16. In the process of FIG. 5, step S44 is executed because the third predetermined time (for example, 60 seconds) has elapsed since the first relay 46 was controlled to be turned on and the second relay 48 was turned off in step S36. This is a case where the temperature of the electric heater 24 has not dropped by a third predetermined temperature width (for example, 15 ° C.) or more. As shown in FIG. 6, if the second relay 48 is operating normally, and controls the first relay 46 turned on at time t _5, the case of controlling turns off the second relay 48, the electric heater 24 is Power is not supplied. Then, since the cooling of the electric heater 24 is performed by driving the blower fan 12, at time t ₆ after the elapse of the third predetermined time from the time t _5, the temperature of the electric heater 24 is a heater temperature immediately after heating operation ends The temperature is equal to or lower than the temperature obtained by subtracting the third predetermined temperature range ΔT ₃ from the first reference heater temperature T ₁ . In contrast, if the ON failure in the second relay 48 occurs, by controlling the first relay 46 turned on at time t _5, the case of controlling turns off the second relay 48, is energized electric heater 24 made The In this case, although the electric heater 24 is gradually cooled by driving the blower fan 12, the temperature does not drop so much because heat is generated by energizing the electric heater 24. Therefore, in the third time t ₆ after a predetermined time from the time t _5, the temperature of the electric heater 24 will exceed the temperature obtained by subtracting a third predetermined temperature range [Delta] T ₃ from the first reference heater temperature T _1. Accordingly, by appropriately setting the third predetermined time and the third predetermined temperature range, it is possible to detect the presence or absence of an on-failure of the second relay 48 by the processing from step S34 to step S44 shown in FIG. it can. After step S44, the control unit 14 controls the first relay 46 to be turned off, and ends the process of FIG.

  If the heater temperature is equal to or less than the value obtained by subtracting the third predetermined temperature width (for example, 15 ° C.) from the first reference heater temperature in step S42 (YES in step S42), the process proceeds to step S46.

  In step S46, the control unit 14 controls the first relay 46 to be turned off and controls the second relay 48 to be turned off.

  In step S <b> 48, the control unit 14 starts measuring time by the timer 44.

  In step S50, the control unit 14 waits until an elapsed time after starting the time measurement by the timer 44 in step S48 reaches an interval time (for example, 0.5 seconds). When the elapsed time reaches the interval time (when it becomes YES), the process proceeds to step S52.

  In step S52, the control unit 14 acquires the second reference heater temperature. In the gas fan heater 2 of the present embodiment, the control unit 14 sets the temperature detected by the heater temperature sensor 32 to the second reference heater temperature.

  In step S54, the control unit 14 controls the first relay 46 to be turned off and controls the second relay 48 to be turned on. In this case, if the first relay 46 is operating normally, the electric heater 24 is not energized. However, when the first relay 46 has an on-failure, the electric heater 24 is energized.

  In step S <b> 56, the control unit 14 starts measuring time by the timer 44.

  In step S58, the control unit 14 waits until the elapsed time after starting the time measurement by the timer 44 in step S56 reaches a fourth predetermined time (for example, 60 seconds). When the elapsed time reaches the fourth predetermined time (when it becomes YES), the process proceeds to step S60.

  In step S60, the control unit 14 determines that the temperature (heater temperature) detected by the heater temperature sensor 32 is equal to or less than a value obtained by subtracting a fourth predetermined temperature range (for example, 5 ° C.) from the second reference heater temperature acquired in step S52. It is determined whether or not. When the heater temperature exceeds a value obtained by subtracting a fourth predetermined temperature width (for example, 5 ° C.) from the second reference heater temperature (NO in step S60), the process proceeds to step S62.

In step S <b> 62, the control unit 14 determines that an ON failure has occurred in the first relay 46, and notifies the user that an ON failure has occurred in the first relay 46 via the operation unit 16. In the process of FIG. 5, step S62 is executed because the fourth predetermined time (for example, 60 seconds) has elapsed since the first relay 46 is controlled to be turned off and the second relay 48 is turned on in step S54. This is a case where the temperature of the electric heater 24 has not dropped by a fourth predetermined temperature width (for example, 5 ° C.) or more until this time. As shown in FIG. 6, if the first relay 46 is operating normally, the first relay 46 is controlled to be turned off at time t _7, when controlling the second relay 48 ON, the electric heater 24 is Power is not supplied. Then, since the cooling of the electric heater 24 is performed by driving the blower fan 12, at time t ₈ after a lapse of a fourth predetermined time from the time t _7, the temperature of the electric heater 24 is a heater temperature at time t ₇ to a temperature below the second reference heater temperature T ₂ by subtracting a fourth predetermined temperature range [Delta] T _4. In contrast, if the ON failure in the first relay 46 is occurring, the first relay 46 is controlled to be turned off at time t _7, when controlling the second relay 48 ON, the energization to the electric heater 24 made The In this case, although the temperature of the electric heater 24 is gradually cooled by driving the blower fan 12, heat is generated by energization of the electric heater 24, and thus the temperature is gradually increased. Therefore, in the fourth time t ₈ after a predetermined time from the time t _7, the temperature of the electric heater 24 will exceed the temperature obtained by subtracting a fourth predetermined temperature range [Delta] T ₄ from the second reference heater temperature T _2. Accordingly, by appropriately setting the fourth predetermined time and the fourth predetermined temperature range, it is possible to detect the presence or absence of an on-failure of the first relay 46 by the processing from step S52 to step S62 shown in FIG. it can. After step S62, the control unit 14 controls the second relay 48 to be turned off, and ends the process of FIG.

  If the heater temperature is equal to or smaller than the value obtained by subtracting the fourth predetermined temperature width (for example, 5 ° C.) from the second reference heater temperature in step S60 (YES in step S60), the process proceeds to step S64.

  In step S64, the control unit 14 controls the first relay 46 to be turned off and the second relay 48 to be turned off. After step S64, the control unit 14 ends the process of FIG. 5 and continues the post-purge operation.

  In the process shown in FIG. 5, the rotational speed when driving the blower fan 12 in step S <b> 32 may be increased or decreased according to the length of the combustion time of the burner 10 in the heating operation performed just before. Further, the third predetermined temperature range used in the determination in step S42 and the fourth predetermined temperature range used in the determination in step S60 may be increased or decreased according to the number of revolutions when driving the blower fan 12 in step S32. .

  As described above, the gas fan heater 2 according to this embodiment includes the casing 18 including the air supply port 4 and the air outlet 6, the burner 10 that burns the city gas and heats the air, and converts the electric power into heat. The electric heater 24 that heats the air and the power supply line to the electric heater 24 are provided, and energization to the electric heater 24 is permitted when it is on, and energization to the electric heater 24 is prohibited when it is off. The first relay 46 (or the second relay 48), the heater temperature sensor 32 for detecting the temperature of the electric heater 24, and air is taken in from the room through the air supply port 4, and the burner 10 and the electric heater 24 are passed through. And the ventilation fan 12 which sends out air indoors through the blower outlet 6, and the control part 14 are provided. The controller 14 controls the first relay 46 (or the first relay 46) based on the change over time of the temperature detected by the heater temperature sensor 32 when the first relay 46 (or the second relay 48) is controlled to be turned off. 2) It is determined whether or not there is an ON failure of the relay 48).

  As shown in FIG. 3, in the gas fan heater 2 of the present embodiment, the control unit 14 controls the first relay 46 (or the second relay 48) to be turned off when the gas fan heater 2 is powered on. When the temperature detected by the heater temperature sensor 32 rises in the state where the first relay 46 (or the second relay 48) is on, it is determined that the on-failure has occurred.

  As shown in FIG. 5, in the gas fan heater 2 of the present embodiment, the control unit 14 controls the first relay 46 (or the second relay 48) to be turned off when the heating operation using the electric heater 24 is finished. In this state, the temperature detected by the heater temperature sensor 32 is a temperature obtained by subtracting the third predetermined temperature range from the first reference heater temperature when the third predetermined time (or the fourth predetermined time) elapses (or If the temperature does not fall below (the temperature obtained by subtracting the fourth predetermined temperature range from the second reference heater temperature), it is determined that the first relay 46 (or the second relay 48) is on.

  In the above-described example, the gas fan heater 2 is illustrated and described as an embodiment of the hot air heater. However, the hot air heater disclosed in the present specification is not limited to this, for example, an oil fan. A heater, a gas stove, an oil stove, or the like may be used.

  In the above embodiment, the hot air heater uses the air taken in from the room via the air supply port as combustion air for the burner, and sends the combustion exhaust gas from the burner into the room through the outlet. Although the case where it is what is called an open type warm air heater was demonstrated, the warm air heater which this specification discloses is not restricted to this. The warm air heater disclosed in this specification uses, for example, so-called half-air that uses air taken in from a room via an air supply port as combustion air for the burner and discharges combustion exhaust gas from the burner to the outside. It may be a closed type hot air heater, or the so-called closed type hot air heater that uses the air taken from the outside as combustion air for the burner and discharges the combustion exhaust gas from the burner to the outside. It may be.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Gas fan heater 4: Air supply port 6: Air outlet 8: Gas supply pipe 10: Burner 12: Blower fan 14: Control unit 16: Operation unit 18: Housing 20: Internal air passage 22: Air filter 24: Electricity Heater 26: Open / close valve 28: Igniter 30: Indoor temperature sensor 32: Heater temperature sensor 34: Operation switch 36: Abnormality alarm buzzer 38: Temperature setting unit 40: Display unit 42: Memory 44: Timer 46: First relay 48: First 2 relays

Claims (3)

A housing having an air supply opening and an air outlet;
A burner that burns fuel and heats the air;
An electric heater that converts electric power into heat and heats the air;
A relay provided on the power supply line to the electric heater, allowing energization to the electric heater when on, and prohibiting energization to the electric heater when off;
A heater temperature sensor for detecting the temperature of the electric heater;
A blower fan that takes in air from the room through the air supply port, passes the burner and the electric heater, and sends the air into the room through the air outlet;
Equipped with a control device,
A hot air heater that determines whether or not a relay is on failure based on a change with time of a temperature detected by a heater temperature sensor when the control device controls the relay to be turned off.   When the control device controls the relay to be turned off when the hot air heater is turned on and the temperature detected by the heater temperature sensor rises, it is determined that the relay is on. The hot air heater according to claim 1.   When the temperature detected by the heater temperature sensor does not drop to the predetermined temperature when the predetermined time has elapsed with the control device turning off the relay when the heating operation using the electric heater is finished. The hot air heater according to claim 1, wherein the relay determines that the relay is on.

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