JPH04113165A - Heater - Google Patents

Abstract

PURPOSE:To minimize energy consumption and prevent a drop in room temperature by interrupting heating when room temperature exceeds a second reference temperature and operating a heater under temperature control based on a first reference temperature when it fails to exceed said second reference temperature. CONSTITUTION:When a room temperature drop prevention switch 27 is turned on, a heater carries out weak combustion for a specified time irrespective of a preset temperature and a detected temperature of a thermistor 23. When room temperature T exceeds 16 deg.C, for example, the amount of heating is too excessive to prevent a drop in the room temperature. Therefore, it is necessary to halt combustion once. On the other hand, when the room temperature fails to exceed 16 deg.C, 14 deg.C is specified as a preset temperature so that temperature control may be carried out based on the thermistor 23. Then, when a specified time has passed after the suspension of combustion, if the room temperature exceeds 16 deg.C, it is necessary to continue combustion suspension. If the room temperature is lower than 16 deg.C, reheating is carried out where 14 deg.C is specified as a preset temperature and room temperature control is carried out based on a detection temperature of the thermistor 23 so as to compensate the excessive drop in the room temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heater that detects indoor temperature and controls the amount of heating by a heating means.

[Conventional technology] For example, in a gas hot air heater, temperature control is performed to determine the combustion amount of the burner by comparing the indoor temperature detected by a thermistor with the temperature set by a temperature setting device. The blower is driven at a rotation speed corresponding to the rotation speed.

In addition, with these heaters, in order to prevent the indoor temperature from dropping too much during sleep, the normal setting temperature (16 to 2
A weak operation switch is provided with a set temperature of, for example, 10°C, which is far from 6°C, so that heating can be performed with the minimum combustion amount of the burner regardless of the room temperature.

[Problem to be solved by the invention] When heating a room using such a heater, for example, if the room being heated is temporarily vacated, it is necessary to stop the heater in the vacated room. If you let it happen,
The temperature of the room will drop while you leave the room, so even if you restart the heater when you return to the room,
There are problems in that it takes time for the indoor temperature to return to the original temperature, the perceived heating effect is small, and problems occur.

In such cases, it is necessary to lower the set temperature without stopping the operation of the heater, and as mentioned above, if the heating load is small, the room temperature will be lower than the set temperature. As the temperature rises too much, heating is performed more than necessary and fuel is wasted.

The present invention uses a heater that detects the indoor temperature and controls the amount of heating, and when the heated room is temporarily left unoccupied, the present invention prevents the indoor temperature from decreasing and thereby wastes energy. The first object of the present invention is to provide a heater that does not consume energy such as fuel.

A second object of the present invention is to provide a heater that provides an excellent heating effect for the user in the initial stage of use of the heater.

[Means for Solving the Problems] A first aspect of the present invention is to determine the heating amount of the heating means based on the indoor temperature detected by the indoor temperature detection means and the set temperature set by the temperature setting means. In a heater that performs temperature control operation, a room temperature drop prevention switch is provided to prevent a drop in indoor temperature, and a first reference temperature that is sufficiently lower than a set temperature that can be set by the temperature setting means and a first reference temperature that is When a second reference temperature higher than the first reference temperature is set and the room temperature drop prevention switch is operated, the room temperature is compared with the second reference temperature at predetermined intervals, and the room temperature is If the room temperature is lower than the second reference temperature, the temperature control operation is performed using the first reference temperature as a target temperature, and if the room temperature is higher than the second reference temperature, the heating by the heating means is interrupted. technical means to do so.

A second aspect of the present invention is that the heating means is arranged in a blower duct in which a blower is disposed, and the blower is operated at least at a minimum rotation speed when the heating of the heating means is interrupted. good.

A third aspect of the invention provides temperature control control in which a heating means and a blower are disposed in a blower duct, and a target heating amount with a rated heating amount as an upper limit is determined from a set temperature by a temperature setting means and a detected temperature by an indoor temperature sensing means. and in a heating device that controls the heating means and the blower based on the target heating amount, a high temperature switch is provided for increasing the temperature of the hot air blown out from the blower duct, and when the high temperature switch is operated. The technical means is to set the heating amount of the heating means to a maximum heating amount larger than the rated heating amount, and to set the rotation speed of the blower to a rotation speed lower than the rotation speed corresponding to the maximum heating amount. .

In a fourth invention, in the third invention, the operation accompanying the operation of the high temperature switch is performed for a predetermined period of time, and at a certain period of time after the elapse of the predetermined period, the target heating amount in the temperature control control is adjusted to The technical means is to heat the eye to the maximum amount.

[Function] In the first aspect of the present invention, when the room temperature drop prevention switch is operated, the indoor temperature is compared with the second reference temperature after a predetermined period of time has elapsed, and, for example, the room temperature is compared with the second reference temperature, and the first reference temperature is set as the target temperature. Temperature control operation is performed.

Since the first reference temperature is sufficiently lower than the temperature that can be set by the temperature setting means, the amount of heating by the temperature control operation is controlled to be small.

Further, when a predetermined period of time has elapsed during temperature control operation, the indoor temperature is compared with a second reference temperature.

In this comparison, when the indoor temperature is higher than the second reference temperature, if the temperature control operation is performed based on the first reference temperature, the amount of heating will decrease even if the heating means heats at the minimum heating amount. This means that it is too large, so heating by the heating means is interrupted.

Conversely, when the indoor temperature is lower than the second reference temperature, even if the temperature control operation is performed based on the first reference temperature lower than the set temperature set by the temperature setting means, the first reference temperature Although it is not possible to heat the room within 10 minutes, the room temperature is maintained near the first reference temperature as a result of heating, so the room temperature does not drop too much.

In the second invention, since the blower operates when the heating means is stopped, the indoor air is diffused by the air blown out from the blower duct, so the indoor temperature is made uniform, and the heating means is not affected by the temperature detection. It is difficult to be directly affected and increases the reliability of detected temperature.

In the third invention, when the high temperature switch is operated, the heating amount of the heating means becomes a maximum heating amount larger than the rated heating amount,
The rotation speed of the blower becomes lower than the amount of heating corresponding to the maximum amount of heating, and the amount of air blown decreases.

Therefore, the temperature of the hot air blown out increases.

In the third invention, the maximum heating amount that cannot be obtained by normal temperature control can be obtained depending on the relationship between the room temperature and the set temperature, so the maximum heating capacity is improved.

Therefore, the heating effect becomes greater.

[Effects of the Invention] In the first aspect of the present invention, when the indoor room is temporarily vacated, if the room temperature drop prevention switch is operated, the heating is adjusted to the first reference temperature for preventing the room temperature from dropping. When the load is small and the amount of heating is more than enough even if the minimum heating amount of the heating means is heated, the heating of the heating means is stopped at a predetermined time interval, thereby reducing the consumption of energy such as fuel. be able to.

On the other hand, when the heating load is large, the temperature control operation is performed based on the first reference temperature, so it is possible to prevent the room temperature from decreasing.

In the second invention, since the reliability of room temperature detection is improved, it is possible to further prevent a decrease in indoor temperature.

In the third invention, since the temperature of the hot air blown out becomes high,
The perceived heating effect is improved. Therefore, even when the indoor temperature is still low, such as when the heater is first used, an excellent heating effect can be obtained.

In the fourth invention, since the maximum heating capacity is improved, the heating effect for the entire room is increased.

Therefore, even when the indoor temperature is low, an excellent heating effect can be quickly obtained without causing any discomfort.

[Example] Next, the present invention will be explained based on examples.

Stationary gas hot air heater 1 shown in Figures 2 and 3
The outer casing 2 is formed from several members made of metal plates and resin, and the outer casing 2 has an indoor air intake port 3 and a combustion air intake port 4, each consisting of a plurality of small openings, located at the upper part of the back surface. Furthermore, warm air outlets 5 for blowing out hot air are provided at the lower part of the front surface, and the indoor air intake port 3 and the suction port 4 are covered by a filter 6 that is detachably provided on the outer casing 2.

As shown in FIG. 4, a convection duct 7 is provided inside the outer casing 2, and a once-through type convection fan 8 that uses the convection duct 7 as a blower casing is installed near the hot air outlet 5 in the convection duct 7. are arranged, and the suction port 4 and the hot air outlet 5 are the upstream end and downstream end of the convection duct 7, respectively.

Note that the convection fan 8 drives an impeller 8a disposed within the convection duct 7 by a DC motor 8b.

The hot air outlet 5 is equipped with a damper 9 for closing a part of the hot air outlet 5, which rotates according to the operating state to control the blowing state of the airflow passing through the convection duct 7.

Here, when closing a part of the hot air outlet 5, the damper 9 closes approximately the upper half of the hot air outlet 5, as shown in FIG. As shown in FIG. 6, the hot air outlet 5 opens outward so as to come into close contact with the upper end surface of the hot air outlet 5.

On the other hand, a burner 10 as a heating means is arranged upstream of the convection fan 8 in the convection duct 7.
The high-temperature combustion gas generated is mixed with indoor air taken in from the indoor air intake port 3 as the convection fan 8 operates, becomes warm air, and is blown out from the hot air outlet 5.

A nozzle 13 that serves as the downstream end of a fuel supply path 12 that guides fuel gas is disposed in an air guide pipe 11 that guides combustion air from the suction port 4 to the burner 10. guided to the mixing chamber 14 along with the air,
Burner 10 burns.

The fuel supply path 12 is provided with two electromagnetic valves 15 and 16 and a gas governor 17 for keeping the supply gas pressure constant from the upstream side, and further downstream thereof a proportional valve for adjusting the amount of fuel gas. 18 are provided.

In the vicinity of the burner 10, an ignition electrode 21 for generating a spark discharge for ignition and a thermocouple 22 for monitoring the combustion state of the burner 10 are provided.

Further, a thermistor 23 is provided inside the suction port 4 to detect the indoor temperature.

On the upper surface of the outer casing 2 of the gas hot air heater 1 configured as described above, there is an operation switch 24 for instructing start and stop of operation, and a resin-made open/close switch. 25, and includes a plurality of switches and a display device for performing various operations to be described later. Stopping and heating amount are controlled.

The control device 30 includes a microcomputer (hereinafter referred to as "microcomputer") equipped with various input/output circuits, and a drive circuit for driving each part of the gas hot air heater 1 by the microcomputer. Several functional parts are formed.

Here, the operation control section 31 and the capacity determination section 32 will be mainly explained, and other parts will be explained, such as the proportional valve control section 33, the fan control section 34,
The damper control section 35 will also be briefly explained.

The operation control unit 31 performs operation start control in a predetermined sequence in response to the operation signal of the operation switch 24, and starts ignition control of the burner 10, and during combustion, in response to the operation signal of the operation switch 24. to perform operation stop control.
A predetermined extinguishing control is performed, and following the ignition control, ignition detection is performed by the thermocouple 22, and when the output voltage of the thermocouple 22 exceeds a certain voltage, it is determined that the ignition detection state is present.

Further, during combustion, whether or not combustion is normal is determined by whether or not the output voltage of the thermocouple 22 is equal to or higher than a predetermined voltage.

In this embodiment, when the heating capacity determined by the capacity determination unit 32 described later is level 2 or lower, 10 mV is used as the reference voltage, and when the heating capacity is level 3 to 7, 14 mV is used as the reference voltage.
Using V as a reference voltage, the output voltage of the thermocouple 22 is compared with the reference voltage, and if it is less than the reference voltage, it is determined that there is an oxygen-deficient combustion state or a misfire state, and extinguishing control is performed.

In the operation start control, the burner 10 is ignited after a pre-purge for 3 seconds, and in the operation stop control, the burner 10 is extinguished and then a boss purge is performed for about 20 seconds.

The capacity determining unit 32 determines the heating capacity, which is a reference for determining the combustion amount of the burner 10 and the voltage applied to the convection fan 8, based on the temperature set by the setting switch 26 and the thermistor 23.
It is determined from the indoor temperature detected by

Here, the set temperature set by the setting switch 26 is rL (corresponding to about 10°C) and 16°C.
, "18°C", . . . , "26°C", rH (for continuous strong operation)", and there are 8 stages in increments of 2°C.

On the other hand, the heating capacity to be determined is preset in seven stages from level 1, which is the weakest heating capacity, to level 7, which has the highest heating capacity as the rated heating amount, as shown in Figure 7. As shown, setting switch 26
According to the temperature detected by the thermistor 23 with respect to the set temperature, the heating capacity is determined from the temperature difference.If "L" or "rH" is set as the set temperature, the heating capacity will be at the level regardless of the detected temperature. 7 or level 1, respectively.

In addition, in the initial stage of operation accompanying the operation of the operation switch 26, level 4 is determined in order to facilitate the ignition of the burner 10, and once ignition is detected, for a predetermined period of time (15 minutes) thereafter, In order to perform layer heating (hot dash) operation, the amount of fuel gas supplied is set to a predetermined amount (for example, 15%).
Level 8, which is the maximum heating amount that is larger than Level 7, which is the rated heating amount that increases by Heating capacity is determined based on this.

In addition, the capacity determination unit 32 is provided with a high temperature switch 28 that is operated separately from the rapid heating (hot dash) operation at the initial stage of operation accompanying the operation of the operation switch 26, and when the high temperature switch 28 is operated, high temperature control is performed. I do.

Hereinafter, high temperature control will be explained based on FIG.

When the high temperature switch 28 is operated (YES in step 1), the amount of combustion in the burner 10 is determined by the rated heating amount of the heating capacity determined by the capacity determination unit 32, regardless of the temperature set by the setting switch 26 and the indoor temperature determined by the thermistor 23. A level 8 combustion amount corresponding to a maximum heating amount larger than level 7 is instructed (step 2), and a current value instruction is given to the proportional valve control unit 33 accordingly, and the convection fan 8 corresponds to level 8. A rotation speed lower than the specified rotation speed is instructed (step 3), and the fan control unit 34 is instructed to
A current value corresponding to the rotation speed is specified.

As a result, the amount of air blown is reduced to less than the amount of air blown relative to the combustion amount of the burner 10 corresponding to heating capacity level 8, and the temperature of the hot air blown out from the hot air outlet 5 is lower than that when the high temperature switch 28 is not operated. This increases the heating effect for the user.

This air flow reduction operation is performed for a certain period of time (for example, 30 seconds) after the high temperature switch 28 is operated (NO in step 4), and when the certain period of time has elapsed (YES in step 4) - the setting switch 26 is activated. Temperature control operation is performed with the target temperature being 2° C. higher than the set temperature (step 5).

In the temperature control operation in step 5, unlike the temperature control operation at the normal rated heating amount, level 8, which is the maximum heating amount larger than the rated heating amount, is determined depending on the set temperature and the detected indoor temperature. heating capacity is improved.

At this time, the combustion amount of the burner 10 corresponds to the heating capacity level determined according to the temperature control operation, but regarding the convection fan 8, the combustion amount corresponds to the heating capacity level determined to be level 8. As in the case of step 3 described above, a rotation speed lower than the rotation speed corresponding to level 8 is instructed, the burner 10 is driven at a rotation speed lower than the rotation speed corresponding to the combustion amount of the burner 10, and the air blowing amount is reduced. .

The temperature control operation in which the target temperature is set 2° C. higher than the set temperature is performed until 30 minutes have elapsed since the high temperature switch 28 was operated (NO in step 6).

That is, this operation is performed for 29 minutes and 30 seconds after the end of the air flow reduction operation in steps 2 and 3.

As a result, for 30 minutes after the high temperature switch 28 is operated, operation at a high temperature with improved heating capacity can be easily performed without performing a troublesome temperature setting operation using the setting switch 26.

When 30 minutes have elapsed since the high temperature switch 28 was operated (YES in step 6), the temperature control operation is started in which the temperature set by the setting switch is the target temperature in the temperature control operation (step 7).

As described above, in this embodiment, in addition to the heating effect for the entire room, the heating effect felt by the user is appropriately controlled according to the high temperature switch 28.
A heating effect can be quickly provided to the user.

Furthermore, in this embodiment, if the room in which the gas hot air heater 1 is being operated is temporarily vacated and it is clear that the room will come back, the room can be heated quickly when the gas hot air heater 1 returns to the room. In order to prevent the indoor temperature from dropping too much, a room temperature drop prevention switch 27 is provided, and when the room temperature drop prevention switch 27 is operated, room temperature drop prevention control is performed.

Hereinafter, the room temperature drop prevention control will be explained based on FIG. 9.

Step 1 when the room temperature drop prevention switch 27 is operated
1), the heating capacity is determined to be level 1 regardless of the set temperature and the temperature detected by the thermistor 23, and operation is performed in this state for 10 minutes (step 12).

After 10 minutes have elapsed, it is determined whether the indoor temperature has reached 16°C or higher, and if it has reached 16°C or higher (YES in step 13), the heating capacity is set to level 1. Even if there is, the amount of heating is too large to prevent the indoor temperature from decreasing, so combustion is temporarily stopped (step 14).

If the convection fan 8 is stopped in the same way when combustion has stopped, the indoor air will stagnate and the correct indoor temperature cannot be detected. Set the rotation speed (Step 1)
5).

In this case, although the temperature of the hot air blown out from the hot air outlet 5 is not very warm, since the user is leaving the room empty at this time, the user does not feel the air as cold air.

When 10 minutes have passed since combustion has stopped (Step 1)
If the indoor temperature is 16°C or higher (YES in step 17), it is determined again whether the indoor temperature is 16°C or higher, and if it is 16°C or higher (YES in step 17), the process moves to step 14, where the combustion is continued for 10 minutes again. After the time has elapsed, the determination in step 17 is made.

In step 17, if the indoor temperature is lower than 16°C (<No), the indoor temperature has dropped considerably, so the ignition control of the extinguished burner 10 is performed (step 18) to restart heating. , temperature control is performed based on the temperature detected by the thermistor 23 with a set temperature of 14° C. (step 19), and the indoor temperature, which has fallen too low, is raised sufficiently.

On the other hand, in step 13 described above, the indoor temperature is 16°C.
If it is lower (NO), the room temperature has also dropped considerably, so proceed to step 19 and
Temperature control is performed based on the thermistor 23 with a set temperature of 4°C.

When 10 minutes have passed since the start of the temperature control in step 19 (YES in step 20), it is determined whether the indoor temperature is 16°C or higher, and if it is 16°C or higher (YES in step 21). ) Go to step 4 to stop combustion, and if the temperature is lower than 16°C (step 2
1), move to step 9 and turn 14° again.
Temperature control is performed for 10 minutes with C as the set temperature.

By performing the above room temperature drop prevention control, the indoor temperature does not fall below 14° C. even when the heating load is large.

In addition, the heating load is small and the indoor temperature is higher than 14°C.
When the temperature rises to 6° C. or higher, combustion in the burner 10 is stopped, so that fuel gas is not wasted.

In addition, the capacity determination unit 32 is equipped with a save operation switch (not shown) for preventing excessive heating according to the user's wishes, and if the save operation switch is operated during operation, the save operation switch (not shown) The set temperature is lowered by 1° C. every time, for example, 30 minutes elapse after the operation lamp is turned on and the temperature detected by the thermistor 23 reaches the set temperature.

As a result, if the room is sufficiently heated for the set temperature, the apparent set temperature will be
Since the actual set temperature gradually becomes lower, there is no need for the user to change the set temperature again, and fuel gas consumption can be suppressed.

The proportional valve control section 33 drives and controls the proportional valve 18 according to the heating capacity determined by the determining section 32 .

Here, in order to ensure that the current value corresponding to the determined heating capacity is energized, a variable resistor is provided which is adjusted by manual operation, and the correction value given by the variable resistor is determined. The proportional valve 18 is driven based on the control value combined with the heating capacity.

The fan control unit 34 drives and controls the convection fan 8 to a rotation speed according to the heating capacity determined by the capacity determination unit 32. Here, in order to drive at a rotation speed corresponding to the determined heating capacity, two variable resistors that are manually adjusted are provided, and when the determined heating capacity is level 1.2, one A voltage is applied based on a control value that is a combination of the correction value given by the variable resistor and the determined heating capacity, and in the case of levels 3 to 7, the correction value given by the other variable resistor is determined. A voltage is applied to the motor of the convection fan 8 based on the control value obtained by combining the heating capacity and the heating capacity.

As a result, even if there are variations in the motor of the convection fan 8, an appropriate voltage corresponding to the control value is applied, and the optimum rotation speed from high rotation speed to low rotation speed can be obtained corresponding to each level. Appropriate air is circulated for the heating amount of the burner 10, ensuring a comfortable hot air temperature and amount for the user.

The damper control unit 35 is a functional unit for driving and controlling the geared motor 9a provided in the damper 9, and at the time of starting and stopping the operation, depending on the control state of the operation control unit 31,
Moreover, during operation, each control is performed according to the heating capacity determined by the capacity determination unit 32.

Here, at the beginning of the operation, it is controlled to be in a closed state, and the opening area of the hot air outlet 5 becomes small. For this reason, while the heating capacity determined by the capacity determination unit 32 described above is level 4 and fuel gas is supplied accordingly, the amount of combustion air supplied is relatively reduced, so the mixing Qi becomes a gas ridge, making it easier to light and ignite.

The damper 9 is opened in response to rapid heating within a predetermined time after the ignition of the burner 10 is detected, and after the rapid heating is completed, the damper 9 is opened to the heating capacity determined by the capacity determination unit 32. Accordingly, it is always closed at level 1,
At level 3 or higher, it is always kept open.

In addition, at level 2, when the heating capacity changes from level 3 or higher to level 2, it remains open, and conversely, when the heating capacity changes from level 1 to level 2, it remains closed. maintain.

On the other hand, the boss barge under operation stoppage control is maintained in the open state to increase the amount of air passing through the convection duct 7 to enable quick cooling of the burner 10 and the convection duct 7, and is closed when the boss barge is finished. Driven.

As a result, when the ignition operation is performed, there is no need to bring the valve into the closed state again, and operation start operations such as pre-purge can be promptly started.

As described above, in the gas warm air fan 1 of this embodiment, when the high temperature switch 28 is operated during operation, the amount of air blown by the convection fan 8 decreases and the temperature of the hot air increases. In addition, after a certain period of time has elapsed, temperature control operation is performed with the target temperature set at 2°C higher than the temperature set by the setting switch 26, eliminating the need for troublesome temperature settings. You can easily raise the indoor temperature without doing this.

Further, when the user temporarily leaves the room to vacate the room, operating the room temperature drop prevention switch 27 will prevent the room temperature from dropping too much. Therefore, when you return to the room, you will not feel completely cold, and when you start operating again, the indoor temperature can be quickly returned to the appropriate temperature.

In this embodiment, the number of heating capacity levels is set to seven levels, but it can also be applied to a system where a large number of heating capacity levels are set or a proportional control system.

In this example, a warm air heater that mixes combustion gas with indoor air and blows it indoors is shown. A forced air supply/exhaust type (FF type) warm air heater that blows air into the room may also be used.

In the above embodiments, only a convection fan is shown, but a blower for supplying combustion air may be provided separately.

Moreover, the fuel may be petroleum.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a part of the functional configuration of a control device for a gas hot air heater according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the front side of the gas hot air heater according to the present embodiment. FIG. 3 is a perspective view showing the rear side of the gas hot air heater of this embodiment, FIG. 4 is a configuration diagram showing the schematic configuration of the gas hot air heater of this embodiment, and FIG.
The figure is a partial front view of the gas hot air heater showing the damper in the closed state of this embodiment, FIG. 6 is a partial front view of the gas hot air heater showing the damper in the open state of this embodiment, and FIG. A characteristic diagram showing the determining characteristics of the heating capacity in the temperature control mode in the capacity determining unit of the control device of this embodiment, FIG. 8 is a flowchart for explaining high temperature control by the capacity determining unit of this embodiment, and FIG. 9 1 is a flowchart for explaining room temperature drop prevention control by the capacity determination section of the present embodiment. In the diagram, 1... Gas hot air heating 8! l (heater), 7...
・Convection duct (air blower duct), 8... Convection fan (air blower), 10... Burner (heating means), 23... Thermistor (indoor temperature detection means), 26... Setting switch (temperature setting means) ), 27... Room temperature drop prevention switch, 28... High temperature switch.

Claims (1)

[Claims] 1) The indoor temperature detected by the indoor temperature detection means;
In a heater that performs temperature control operation in which the heating amount of the heating means is determined based on the set temperature set by the temperature setting means, a room temperature drop prevention switch is provided to prevent a drop in indoor temperature, and the above-mentioned a first reference temperature that is sufficiently lower than the set temperature that can be set by the temperature setting means;
When the second reference temperature is set higher than the reference temperature of If the room temperature is lower than the second reference temperature, the temperature control operation is performed using the first reference temperature as the target temperature, and if the indoor temperature is higher than the second reference temperature, the heating by the heating means is interrupted. A heating machine characterized by: 2) The heating means is disposed in a blower duct in which a blower is arranged, and the blower operates at least at a minimum rotational speed when the heating of the heating means is interrupted. The heating machine mentioned. 3) A heating means and a blower are arranged in the air duct, and temperature control is performed to determine a target heating amount with the rated heating amount as an upper limit from the set temperature by the temperature setting means and the detected temperature by the room temperature detection means, In the heater that controls the heating means and the blower based on the target heating amount, a high temperature switch is provided for increasing the temperature of the hot air blown out from the blower duct, and when the high temperature switch is operated, A heating machine characterized in that the heating amount of the heating means is set to a maximum heating amount larger than the rated heating amount, and the rotation speed of the blower is set to a rotation speed lower than the rotation speed corresponding to the maximum heating amount. 4) The operation accompanying the operation of the high temperature switch is performed for a predetermined period of time, and the upper limit of the target heating amount in the temperature control control is set to the maximum heating amount for a certain period of time after the elapse of the predetermined period of time. The heater according to claim 3.