JPH11166765A - Bath hot water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce as much as possible a time required for hot water filling by effectively utilizing a constitution provided by a bath hot water supply device. SOLUTION: A bath hot water supply device comprises a heat exchanger for hot water supply 4 for supplying hot water to a hot water supply passage 3, a heat exchanger for supplementary heating 6 connected to a bathtub 5 by circulation passages for supplementary water heating 25 and 26, a circulation pump 28 for circulating hot water, an opening and closing means 31 for opening and closing the circulation passages 25 and 26, and a pressure detection type water level sensor 29 for detecting a water level in a bathtub with the opening and closing means 31 being closed. Further, a hot water filling control means H is composed to be able to change to a state of hot water supply to both sides where the opening and closing means 31 is opened to supply hot water to both the circulation passages 25 and 26 and to a state of hot water supply to one side where the opening and closing means 31 is closed to supply hot water to one side of the circulation passages 25 and 26, following a command to start filling hot water, the opening and closing means 31 is closed to detect an initial water level, and if a set water level is not reached, hot water is supplied in a state of hot water supply to both sides, and hot water is filled while detecting a water level at a water level detection timing in a state of hot water supply to one side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply heat exchanger for heating water from a water supply channel to supply hot water to a hot water supply channel, a recirculation path connected to the hot water supply path, and a circulation path thereof. A reheating heat exchanger connected to the bathtub, a circulation pump for circulating hot water through the circulation path, an opening / closing means for opening and closing the circulation path, and hot water in the bathtub when the opening / closing means is closed. The present invention relates to a bath water heater provided with a pressure detection type water level sensor provided in the circulation path for detecting a water level, and a hot water control means for controlling the operation of a burner for heating a heat exchanger and the opening / closing means.

[0002]

2. Description of the Related Art In a bath water heater having such a configuration, a water level in a bathtub is detected by a pressure detection type water level sensor provided in a circulation path. Therefore, conventionally, the circulation of the hot water from the hot water supply heat exchanger from the connection point of the hot water supply path is performed while closing the opening / closing means and detecting the water level in the bathtub with a water level sensor. To one side of the road,
Filling was performed until the target set water level was detected (for example, see Japanese Patent Application Laid-Open No. 2-115657).

[0003]

As described above, in the conventional bath water heater, when hot water is supplied to the bath tub at a set water level to fill the bath, the hot water is supplied from one side of the circulation path connected to the hot water supply path. Since water was supplied, the amount of hot water supplied into the bathtub per unit time was small, and there was a drawback that it took time to fill the bath to the set water level.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to effectively use the configuration provided in a bath water heater and to minimize the time required for filling with hot water. It is to provide a bath water heater that can be used.

[0005]

In order to achieve this object, according to the first aspect of the present invention, the filling control means opens the circuit opening / closing means to open the circulation path from the hot water supply heat exchanger. A two-sided hot water supply state in which hot and cold water is supplied to both sides of the circulation path from a connection point of the hot water supply path, and a one-sided hot water supply state in which the opening / closing means is closed to supply one side of the circulation path from the connection point of the hot water supply path. It is configured to be switchable, and with the start of filling, a closing operation is performed on the opening / closing means to detect an initial water level by the water level sensor, and if the detected initial water level has not reached the set water level, Hot water is supplied in the both-side hot water supply state, and at the water level detection timing, while the one-side hot water supply state detects the water level by the water level sensor, the bath is filled with water until the set water level is reached. In other words, as a result of detecting the initial water level, if the hot water in the bathtub has not reached the set water level, the recirculation path for additional heating is effectively used to supply hot water from the hot water supply path to both sides of the recirculation path. Since the filling is performed, the amount of hot water supplied to the bathtub per unit time is increased as compared with the conventional one-sided hot water filling, so that the time required for filling can be shortened and the water level detection timing can be reached. Then, the water filling is performed while detecting the water level by switching to the one-side hot water supply state, so that the water level in the bathtub can be maintained substantially at the set water level.

According to the second aspect of the invention, when the start of filling is instructed by the filling control means, the amount of water retained in the circulation path inside the vessel of the bath water heater and the longest circulation outside the vessel are determined. The hot water of the sum of the amount of water held in the road is supplied in the above-mentioned hot water supply state on both sides, and thereafter the initial water level of the bathtub is detected. Can be confirmed, and even if air has entered the circulation path, the air in the circulation path is driven out by the hot water supply on both sides to detect the initial water level, so that the detection of the initial water level is surely performed. Even if the initial water level has reached the set water level, the amount of hot water supplied by both-side hot water supply is the minimum amount necessary to expel air in the circulation path, so that the rise in water level in the bathtub is minimized. That Kill.

According to the third aspect of the present invention, since the filling control means stops the filling when the initial water level is detected by the water level sensor, the initial water level reaches the set water level. In this case, the rise in the water level in the bathtub can be further suppressed, and the water level can be made closer to the set water level.

According to the fourth aspect of the invention, when the water level in the bathtub reaches a predetermined water level lower than the set water level, the hot water control means detects a water level by a water level sensor in the one-side hot water supply state. Since the filling is performed, it is possible to perform the efficient filling in the above-described hot water supply state on both sides until the water level reaches the predetermined water level lower than the set water level. By appropriately selecting the water level, it becomes possible to keep the water level in the bathtub almost at the set water level while filling the bathtub as efficiently as possible.

According to the invention described in claim 5, the hot water filling control means changes the temperature of the hot water of the hot water by a predetermined temperature in a hot water supply state on both sides before the water level in the bathtub reaches the set water level. After a fixed amount of hot water is supplied, the hot water is circulated by the circulating pump after the hot water is stopped, and the temperature of the hot circulating water is detected by hot water temperature detecting means provided on the upstream side in the circulating direction with respect to the opening / closing means. When the temperature changes from the changed predetermined temperature to the hot water side before the change, the detected temperature at that time is determined to be the hot water temperature of the bathtub. For example, the hot water in the bathtub is provided with hot water temperature detecting means. Enough time to get to the location,
Compared to circulating hot water with a circulation pump and then detecting hot water temperature, the hot water temperature in the bathtub can be detected more reliably in a short time, and the hot water temperature of the bathtub can be set. If the temperature is lower than the temperature, the hot water is circulated by the circulation pump and the hot water in the bath tub is additionally heated by the additional heat exchanger, so that the additional heating to the set temperature can be performed in a short time.

According to the sixth aspect of the present invention, when the temperature of the hot water in the bath tub reaches a predetermined temperature lower than the set temperature, the hot water filling control means activates the notification means. For example, by notifying at a time point of about 1 to 2 ° C. lower than the set temperature, it is also possible to set so that the set temperature will be just set at the time of actual bathing, so that a bather can take a bath as quickly as possible. Can be reported.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A bath water heater according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the water heater main body A heats water from a water supply channel 1 as a water intake channel connected to a general household water pipe, and includes a hot water tap 2 at a tip of the heated hot water. Combustion in which a fin tube type heat exchanger 4 for supplying hot water to the hot water supply path 3 and a fin tube type additional heat exchanger 6 for heating the water in the bathtub 5 and reheating the same are provided inside the casing. Prepared indoors, these hot water supply heat exchanger 4
The additional heat exchanger 6 is configured to be heated by a single hot water supply gas burner 7.

A gas supply path 8 for supplying general household fuel gas is connected to a hot water supply gas burner 7 for heating the hot water supply heat exchanger 4 and the additional heating heat exchanger 6. The gas supply path 8 is provided with a main gas solenoid valve 9, a main gas valve 10 for switching a fuel gas supply state to the hot water supply gas burner 7, and a gas proportional valve 11 for changing and adjusting the fuel gas supply amount. . Further, a fan 12 capable of adjusting the supply amount of combustion air to the hot water supply gas burner 7 is provided, and an ignition igniter 1 for executing an ignition operation for the hot water supply gas burner 7 is provided near the hot water supply gas burner 7.
3. A frame rod 14 for detecting whether or not the hot water supply gas burner 7 is ignited is provided.

The water supply passage 1 is provided with a water supply thermistor 15 for detecting a water supply temperature and a water amount sensor 16 for detecting a water supply amount. Then, the water supply channel 1 and the hot water supply channel 3 downstream of the water supply thermistor 15 and the water amount sensor 16 are connected via a water supply bypass 17 so as to bypass the hot water supply heat exchanger 4. The hot water supply path 3 includes, in order from the upstream side, a hot water supply thermistor 18 for detecting the temperature of hot water from the hot water supply heat exchanger 4, and a hot water supply from the hot water supply heat exchanger 4 and a water flow from the water supply bypass path 17. Mixing valve 19 for adjusting the mixing ratio, tap water thermistor 20 for detecting the temperature of the hot and cold water mixed by mixing valve 19, water proportional valve 21 for adjusting the amount of hot and cold water, and interrupt for detecting an interrupt of general hot water supply A water sensor 22 is provided.

The hot water supply heat exchanger 4 is provided with a boiling prevention thermistor 23 for detecting the temperature of hot water in the hot water supply heat exchanger 4. Also, the mixing valve 19
Is provided at a connection point between the water supply bypass passage 17 and the hot water supply passage 3, and supplies hot water from the hot water supply passage 3 to the bathtub 5 in the hot water supply passage 3 between the water proportional valve 21 and the interruption water amount sensor 22. The hot water path 24 for a bath is branched and connected.

A return path 25 for the bathtub from the bathtub 5 and a forward path 26 for the bathtub are connected to the additional heat exchanger 6. The return path 25 for the bathtub and the forward path 26 for the bathtub are connected to the bath adapter 2.
A circulation path is connected to the hot tub 5 via the hot water path 3 and is connected to the hot tub 5 via the hot water path 24. In addition,
The circulation paths 25 and 26 include a piping system inside the water heater main body A and a piping system outside the water heater main body A, and the maximum length of the piping system from the water heater main body A to the bathtub 5 is, for example, 5
Meters.

Then, by driving the additional heating circulation pump 28 provided in the bathtub return path 25, hot water in the bathtub 5 is circulated through the bathtub return path 25 and the bathtub forward path 26 while being circulated. It is configured to fire. That is,
The hot and cold water in the bathtub 5 is supplied to the reheating heat exchanger 6 via the return path 25 for the bathtub, and the heated hot water is supplied into the bathtub 5 via the bathtub going path 26. .

The bathtub return path 25 includes, in order from the upstream side, a pressure detection type water level sensor 29 for detecting the water level in the bathtub 5 by detecting pressure, and a return for the bathtub as hot water temperature detecting means. Thermistor 30 and return path 25 for bathtub
Bath two-way valve 31 as electromagnetic opening and closing means for opening and closing
, A reheating circulation pump 28 for circulating hot and cold water and a water flow switch 32 are provided. And bathtub going path 26
Is provided with an outgoing thermistor 33 for a bathtub. A hot water supply path 24 for supplying hot water from the hot water supply path 3 to the bathtub 5 includes a circulation pump 28 for additional heating and a water flow switch 3.
2 is connected to the bathtub return path 25. The hot water path 24 is provided with a hot water electromagnetic valve 34 for opening and closing the hot water path 24 from the upstream side, and a hot water check valve 35.

Further, the filling valve solenoid valve 34 and the filling check valve 3
5 is provided with an air layer forming hopper 36 communicating with the hot water path 24. This air layer forming hopper 36 has a drainage channel 37 for draining hot and cold water.
And an electromagnetic drain valve 38 for opening and closing the drain passage 37, and an end of the drain passage 37 is connected to the bathtub return passage 25 between the bath two-way valve 31 and the reheating pump 28. Have been.

The control section H as a filling control means for controlling the operation of the bath water heater includes a microcomputer and is configured to be able to communicate with a remote controller R. And
The remote control R includes an operation switch 39 for instructing start and stop of operation, a hot water switch 40 for instructing hot water operation,
A reheating switch 41 for instructing a reheating operation, a temperature setting switch 42 for setting a general hot water supply temperature or a hot water supply temperature, a water level switch 43 for setting a set water level at the time of hot water filling, and a notification means for notifying a bathable state. And an alarm 44 or the like. Note that the remote control R as described above
May be one or a plurality of them.

After the installation of the bath water heater having the above-described configuration, a test operation is performed in the same manner as before, and the water level sensor 29 detects when the bath adapter 27 of the bathtub 5 is not submerged. The value, that is, the detection value of the water level sensor 29 is a constant value until the bath adapter 27 is submerged. The detection value at this time, the detection value of the water level sensor 29 when the bath adapter 27 is just submerged, and the bathtub 5 The detection value of the water level sensor 29 when the water level in the inside reaches the set water level is read, and each value is stored in the storage unit of the control unit H, and the amount of hot water required to raise the water level in the bathtub 5 by a predetermined amount. For example, if the water level in the bathtub 5 is 1
The approximate amount of hot water necessary for raising the centimeter is set and stored in the storage unit of the control unit H.

The control operation of the bath water heater by the control unit H will be described. First, when the operation switch 39 of the remote control R is turned on, the general hot water supply operation from the hot water tap 2 and the hot water filling operation are enabled. Then, the hot water tap 2 is opened and the water amount sensor 1 is opened.
When the amount of water detected by Step 6 becomes equal to or more than a predetermined amount, the general hot water supply operation is started, and when the hot water switch 40 is turned on, the hot water operation is started. Start the burning operation.

In the general hot water supply operation, when the water amount detected by the water amount sensor 16 exceeds a predetermined amount, the fan 12 is driven, and then the original gas solenoid valve 9, the main gas valve 10, the gas proportional valve 1
1 is opened to supply the fuel gas to the hot water supply gas burner 7, the ignition operation by the igniter 13 is started, and the hot water supply burner 7 is
It is detected whether or not it is ignited.

When the hot water supply gas burner 7 is ignited, the gas proportional valve 11 is controlled based on the hot water supply temperature set by the temperature setting switch 42 of the remote controller R, the water temperature detected by the water supply thermistor 15, the water amount detected by the water amount sensor 16, and the like. So-called feedforward control is performed so that the fuel gas supply amount is adjusted by adjusting the opening degree, and the supply amount of combustion air by the fan 12 is adjusted so that the hot water supply temperature becomes the set temperature.

In addition to the feedforward control, the opening degree of the gas proportional valve 11 is finely adjusted based on the deviation between the hot water supply temperature set by the temperature setting switch 42 of the remote controller R and the hot water temperature detected by the tapping thermistor 20. Feedback control is executed, and the temperature setting switch 4
The hot water at the temperature set by 2 is supplied from the hot water tap 2. Then, when the hot water tap 2 is closed and the water amount sensor 16 stops detecting a predetermined amount of water flow, the original gas solenoid valve 9 and the main gas valve 1
0, each of the gas proportional valves 11 is closed to stop the combustion of the hot water supply gas burner 7, and after a certain period of time, the fan 12 is also stopped to end the general hot water supply operation.

In the hot water filling operation for filling the bathtub 5, the hot water supply gas burner 7 is ignited and feedforward control and feedback control are performed in the same manner as in the general hot water supply operation described above, and the hot water filling electromagnetic valve 34 is opened. Then, hot water from the hot water supply path 3 is supplied to the bathtub 5 to perform hot water filling, and the temperature of the hot water in the bathtub 5 is set to the bath set temperature. More specifically, as shown in the flowchart of FIG.
The bath two-way valve 31 is opened to switch to the hot water supply state on both sides, and hot water from the hot water supply path 3 is supplied to the bath tub 5 from the return path 25 for the bath tub and the forward path 26 for the bath tub via the hot water path 24. Tension is performed by a predetermined amount, for example, 6 liters (step 1). The amount of 6 liters depends on the amount of water retained in the piping system inside the water heater main body A in the circulation paths 25 and 26 for additional heating, and the length of the longest piping system outside the water heater main body A, for example, a 5-meter piping system. Set to the sum of the amount of water held.

The two-way bath valve 31 and the hot water-filled solenoid valve 3
4 is closed for a very short time (for example, 15 seconds)
The water level in the bathtub 5 is read by the water level sensor 29 (step 2). When the water level in the bathtub 5 is read, the water filling electromagnetic valve 34 is closed and detected as described above. However, with the water filling electromagnetic valve 34 opened, the bath two-way valve 31 is opened. Close the valve and switch to the one-side hot water supply state, and go to the bathway 2
The water level in the bathtub 5 may be read while filling only 6.

When the detected water level Sk of the water level sensor 29 is lower than the set water level Ss, additional hot water is supplied from the detected water level Sk to a water level Ss-α lower than the set water level Ss by a predetermined water level α. The predetermined water level α corresponds to the water level from the bottom of the bathtub 5 until the bath adapter 27 is submerged,
In this additional hot water supply, the bath two-way valve 31 is opened to switch to the both-side hot water supply state, and hot water is supplied to the bath tub 5 from both the return path 25 for the bathtub and the outgoing path 26 for the bathtub by the additional hot water supply amount ( Steps 3 and 4). This additional hot water is supplied by the water sensor 1
6 until the accumulated water supply amount Qa reaches the set water level Ss-α until the accumulated water supply amount Qa reaches Qb.
Is reached, it is determined that it is time to detect the water level,
The bath two-way valve 31 is closed for a very short time (for example, 15 seconds) to switch to the one-side hot water supply state to fill only the bathtub outgoing path 26, and the water level in the bathtub 5 is detected by the water level sensor 29. (Step 5).

The detected water level Sk is equal to the set water level Ss
If the detected water level Sk has not reached the water level Ss-α lower than the predetermined water level α by the predetermined water level α, it is determined whether or not the detected water level Sk has reached the reference water level at which the bath adapter 27 is submerged (step 6, step 6).
7). That is, if the detected water level Sk has not reached the reference water level, it is determined that the bathtub plug of the bathtub 5 has been removed, and an alarm or an error is displayed (steps 7 and 8).

If the detected water level Sk has reached a water level Ss-α lower than the set water level Ss by a predetermined water level α, it is determined that the water level has been detected, and the bath two-way valve 31 is closed and the one-side hot water supply state is established. To the set water level Sk
The water filling in the one-side hot water supply state is continued while the water level in the bathtub 5 is detected until the water level reaches s. When the water level becomes equal to or higher than the set water level Ss, the water filling electromagnetic valve 34 is closed and the filling is stopped ( Steps 9-11). Before switching to the one-side hot water supply state, the degree of opening of the gas proportional valve 11 is adjusted with the bath two-way valve 31 opened so that hot water lower by a predetermined value is supplied. Hot water is supplied to the bathtub 5 by a predetermined amount in a hot water supply state on both sides.

After the filling is stopped, the bath two-way valve 31 is opened to drive the reheating pump 28, and the temperature of the hot water in the bathtub 5 is detected by the return thermistor 30 (step 12). At this time, since the low-temperature hot water is filled by a predetermined amount before switching to the one-side hot water supply state as described above, the low-temperature hot water fills the inside of the bathtub return path 25. Therefore, the temperature detected by the return thermistor 30 provided in the bathtub return path 25 is initially low and then high, and the temperature after the high change can be used as the temperature of the hot and cold water in the bathtub 5.

If the detected temperature has reached a temperature lower than the bath set temperature set by the temperature setting switch 42 by a predetermined value T, the alarm 44 of the remote controller R notifies that the temperature is close to the set temperature (step 13). , 1
4). If the detected temperature of the return thermistor 30 has not reached the bath set temperature, a reheating operation to be described later is executed (steps 15 and 16), and if the detected temperature of the return thermistor 30 exceeds the bath set temperature, the reheating operation is performed. To stop,
The drainage on-off valve 38 is opened, and the hopper 36 is
The hot water inside is drained (step 17).

In this manner, the filling of the bathtub 5 can be switched between the both-side hot water supply state and the one-side hot water supply state, and can be executed without stopping the filling of the bathtub 5. Can be shortened, and the water level in the bathtub 5 at the time of completion of hot water filling can be set to a water level as close as possible to the set water level. Note that, when the hot water tap 2 is opened during the hot water filling operation, the general hot water supply operation is prioritized based on the detection by the interruption water amount sensor 22.

The reheating operation for heating the hot water in the bathtub 5 is automatically shifted after the water level in the bathtub 5 becomes higher than the set water level Ss or when the reheating switch 41 of the remote controller R is turned on. The hot water in the bathtub 5 is heated by the additional heat exchanger 6 while the hot water in the bathtub 5 is circulated through the return path 25 for the bathtub and the forward path 26 for the bathtub by the operation of the circulation pump 28 for firing.

More specifically, the reheating circulation pump 2
8, when the hot water supply gas burner 7 is not burning, the fan 12 is driven in accordance with the detection of the water flow by the water flow switch 32, and then the original gas solenoid valve 9 and the main gas valve 10 are opened. Then, the opening degree of the gas proportional valve 11 is adjusted, the igniter 13 ignites the hot water supply gas burner 7, and the combustion of the hot water supply gas burner 7 is started. And
The opening degree of the gas proportional valve 11 is adjusted based on the detected hot water temperature of the going thermistor 33, and the boiling prevention thermistor 23 is used.
Is adjusted to such an extent that the water in the hot water supply heat exchanger 4 does not boil based on the detected temperature.

In this way, when the hot water in the bathtub 5 is heated by the additional heat exchanger 6 and the hot water temperature detected by the return thermistor 30 reaches the bath set temperature of the remote controller R, it is determined that the additional heating operation is completed. Then, the original gas solenoid valve 9, the main gas valve 10, and the gas proportional valve 11 are closed to stop the combustion of the hot water supply gas burner 7, and the fan 12
Is stopped, and the operation of the circulation pump 28 for additional heating is stopped. Note that when the general hot water supply operation is being performed, the general hot water supply operation is continuously performed even after the reheating operation is completed,
After the reheating operation is completed, the water level and the temperature of hot and cold water in the bathtub 5 are automatically detected every predetermined time, and a so-called proper amount and proper temperature keeping operation is performed as needed to keep the water level and the temperature constant. I do.

[Other Embodiments] (1) In the above embodiment, the integrated water supply amount Qa by the water amount sensor 16 reaches the hot water supply amount Qb up to the set water level Ss-α, or the water level Sk detected by the water level sensor 29 becomes the set water level. S
When the water level Ss-α lower than s by a predetermined water level α is reached,
It is determined that it is time to detect the water level, and the water level sensor 2
Although the configuration is such that the water level detection is performed according to No. 9, the water level detection may be performed every time the filling is performed for a certain period of time.

(2) In the above embodiment, when the hot water filling operation is executed, the circulation path 2
Although the configuration is such that the sum of the retained water amount of the piping system inside the water heater main body A at 5 and 26 and the retained water amount of the longest piping system outside the water heater main body A is filled with water.
The actual amount of water retained in the piping system may be set at the time of the test operation described above, and hot water may be filled in both-side hot water supply state based on the set actual amount of retained water. When the hot water filling operation is executed, first, the initial water level in the bathtub 5 is detected, and when the remaining hot water level in the bathtub 5 is equal to or higher than the set water level, the rise in the water level is suppressed and the water level in the bathtub 5 is reduced. May be configured to be held substantially at the set water level.

(3) In the above embodiment, the water level sensor 29
Before the detected water level Sk becomes equal to or higher than the water level Ss-α lower than the set water level Ss by a predetermined water level α, the gas proportional valve 11 is adjusted to supply low-temperature hot and cold water. It can be configured to supply hot and cold water,
Furthermore, it is possible to detect the temperature of the hot water in the bathtub 5 after operating the circulation pump 28 for a certain period of time without intentionally supplying the hot or cold water at a low temperature.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a bath water heater.

FIG. 2 is a flowchart showing a control operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inlet channel 3 Hot water supply channel 4 Heat exchanger for hot water supply 5 Bathtub 6 Heat exchanger for reheating 7 Burner 25, 26 Circulation channel 28 Circulation pump 29 Water level sensor 30 Hot water temperature detecting means 31 Opening / closing means 44 Notification means H Hot filling control means

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masayoshi Hogawa 1-152 Oka, Minami-shi, Minato-ku, Osaka-shi, Osaka

Claims (6)

[Claims] 1. A hot water supply heat exchanger for heating water from a water inlet and supplying hot water to a hot water supply path, a recirculation path connected to the hot water supply path, and a bathtub connected to the recirculation path. Heat exchanger for reheating, a circulation pump for circulating hot and cold water through the circulation path, opening and closing means for opening and closing the circulation path, and detecting the level of the hot and cold water in the bathtub with the opening and closing means closed. A bath water heater comprising: a pressure detection type water level sensor provided in the circulation path; and a hot water control device that controls an operation of a burner for heating a heat exchanger and the open / close device. Means for opening and closing the opening and closing means and supplying hot water from the hot water supply heat exchanger to both sides of the circulation path from a connection point of the hot water supply path to both sides of the circulation path; From the hot water supply connection point to one side of the circulation path Configured to be capable of switching to the one-side hot-water supply state, with the water filling start is commanded, the switching means detects the initial level by then closing operation the water level sensor,
If the detected initial water level has not reached the set water level, hot water is supplied in the double-sided hot water supply state, and at the water level detection timing, the water level is detected by the water level sensor in the one-side hot water supply state until the set water level is reached. Bath water heater configured to perform hot water filling. 2. The hot water filling control means, when instructed to start hot water filling, gives an amount of the sum of the amount of water held in the circulation path inside the vessel of the bath water heater and the amount of water held in the longest circulation path outside the vessel. The hot water supply apparatus according to claim 1, wherein the hot water is supplied in the hot water supply state on both sides, and thereafter, the initial water level is detected. 3. The bath water heater according to claim 1, wherein the water filling control unit is configured to stop the execution of the water filling when the initial water level is detected by the water level sensor. 4. The water filling control means executes water filling while detecting the water level by the water level sensor in the one-side hot water supply state when the water level in the bath tub reaches a predetermined water level lower than a set water level. Claims 1-3 configured as
The bath water heater according to any one of the above. 5. The hot water filling control means, in the both-side hot water supply state before the water level in the bathtub reaches a set water level,
A predetermined amount of hot water is supplied by changing the temperature of the hot water in the hot water, and the hot water is circulated by the circulating pump after the hot water is stopped. Means for detecting the temperature of the circulating hot and cold water, and when the detected hot water temperature changes from the changed predetermined temperature to the hot water side before the change, the detected temperature at that time is determined to be the hot water temperature of the bathtub, The bath according to claim 4, wherein when the hot water temperature of the bathtub is lower than the set temperature, the hot water is circulated by the circulation pump and the hot water in the bathtub is reheated by the reheating heat exchanger. Water heater. 6. The bath filling control means according to claim 5, wherein when the hot water temperature of said bath tub reaches a temperature lower than a set temperature by a predetermined temperature, said hot water filling control means activates a notifying means. Bath water heater.