EP3336445A1

EP3336445A1 - Hot-water heating apparatus

Info

Publication number: EP3336445A1
Application number: EP17191657.0A
Authority: EP
Inventors: Takanobu Fujimoto; Kenichi Watanabe; Hiroshi Arashima; Atsushi Takeuchi; Tohru Harada
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2016-12-16
Filing date: 2017-09-18
Publication date: 2018-06-20
Anticipated expiration: 2037-09-18
Also published as: DK3336445T3; EP3336445B1; JP2018096654A

Abstract

A hot-water heating apparatus includes a heater incorporating a heat pump cycle and a heating cycle in which hot water is circulated through the heater and a heating terminal unit, the hot water being obtained by heating water by the heater. The heating apparatus further includes a circulation pump circulating the hot water in the heating cycle, a circulation quantity detector configured to detect a quantity of the hot water circulated in the heating cycle, and a controller. A determiner determines a quantity level of the hot water circulated in the heating cycle and sends a result of the determined quantity level to a control terminal slave via a network.

Description

BACKGROUND

1. Technical Field

The present disclosure relates to a hot-water heating apparatus configured to send and receive data via a network.

2. Description of the Related Art

Unexamined Japanese Patent Publication No. 2005-121251 presents a conventional hot-water supply management system made up of a water heater operation controller that records various data, a server that stores charts of water heaters and manages programs specified for the water heaters, and a cellular phone that has an infrared communication function and performs remote control of the water heater controller to send and receive data recorded on the controller.
In the conventional hot-water supply management system, the cellular phone is designed to receive, by the use of the infrared communication function, data recorded on the controller for a water heater that has been found to be faulty and to check the data recorded on the controller against a chart of the water heater.
Unfortunately, the conventional system disclosed in the publication does not have a specific configuration for detecting a fault while monitoring the operating state inside a water heater.

SUMMARY

The present disclosure has been accomplished to solve the conventional challenge described above. It is an object of the present disclosure to provide a hot-water heating apparatus that offers enhanced convenience by notifying a control terminal slave of a result determined on the quantity of circulated hot water via a network before the hot-water heating apparatus stops due to an abnormal event.
A hot-water heating apparatus according to an aspect of the present disclosure includes a heater incorporating a heat pump cycle and a heating cycle in which hot water is circulated through the heater and a heating terminal unit, the hot water being obtained by heating water by the heater. The hot-water heating apparatus further includes a circulation pump circulating the hot water in the heating cycle, a circulation quantity detector configured to detect a quantity of hot water circulated in the heating cycle, and a controller. A determiner determines a quantity level of the hot water circulated in the heating cycle and sends a result of the determined quantity level to a control terminal slave via a network.
A hot-water heating apparatus having this configuration offers enhanced convenience by sending a result of the level determined on the quantity of circulated hot water to a control terminal slave via a network before the hot-water heating apparatus stops due to an abnormal event.
According to the aspect of the present disclosure, the hot-water heating apparatus offers enhanced convenience by sending a result of the level determined on the quantity of circulated hot water to the control terminal slave via the network before the hot-water heating apparatus stops due to an abnormal event.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing illustrating a configuration of a hot-water heating apparatus according to an exemplary embodiment of the present disclosure;
FIG. 2 is a schematic graph of an advance notice based on a quantity of hot water circulated in a heating cycle of the apparatus;
FIG. 3 is a schematic graph of another advance notice based on the quantity of hot water circulated in the heating cycle of the apparatus;
FIG. 4 is a schematic graph of an advance notice based on a drive voltage for a circulation pump of the apparatus; and
FIG. 5 is a schematic graph of an advance notice based on a rotation rate of the circulation pump of the apparatus.

DETAILED DESCRIPTION

A hot-water heating apparatus according to a first aspect of the present disclosure includes: a heater incorporating a heat pump cycle; a heating cycle in which hot water is circulated through the heater and a heating terminal unit, the hot water being obtained by heating water by the heater; a circulation pump circulating the hot water in the heating cycle; a circulation quantity detector configured to detect a quantity of hot water circulated in the heating cycle; and a controller. A determiner determines a quantity level of the hot water circulated in the heating cycle and sends a result of the determined quantity level to a control terminal slave via a network. The "result of the determined quantity level" herein includes at least one of observations, namely a decrease in the quantity of hot water circulated in the heating cycle, and a clogging of a water filter.
According to this configuration, the hot-water heating apparatus offers enhanced convenience by sending a result of the level determined on the quantity of circulated hot water to the control terminal slave via the network before the hot-water heating apparatus stops due to an abnormal event.
A hot-water heating apparatus according to a second aspect of the present disclosure is based on the hot-water heating apparatus of the first aspect of the present disclosure, in which the determiner compares the quantity detected at the circulation quantity detector with a predetermined quantity and determines the quantity level of the hot water circulated in the heating cycle.
According to this configuration, the determiner sends a result of the determined quantity level to the control terminal slave via the network if the quantity of hot water circulated in the heating cycle falls below the predetermined quantity while the heater operates and generates the hot water circulated in the heating cycle. This configuration allows a service engineer who performs apparatus repair and other service to take a step such as cleaning of the water filter before the hot-water heating apparatus stops due to an abnormal event resulting from deposition of rust or dust of piping on the water filter disposed in the heating cycle, for example. Consequently, the hot-water heating apparatus prevents the clogging caused by the dust or rust of the piping in the heating cycle.
A hot-water heating apparatus according to a third aspect of the present disclosure is based on the hot-water heating apparatus of the first or second aspect of the present disclosure, in which the circulation quantity detector detects the quantity of hot water circulated in the heating cycle at a plurality of times, and the determiner determines the quantity level of the hot water circulated in the heating cycle in conformity with a change in values of the quantity detected at the circulation quantity detector.
According to this configuration, the timing with which the determiner sends a result of the determined quantity level to the control terminal slave is not immediately before the heating apparatus stops due to an abnormal event. The determiner can predict a decrease in flow rate and send the result of the determined quantity level in advance of an abnormal stoppage of the apparatus. This configuration enables the hot-water heating apparatus to offer enhanced convenience.
A hot-water heating apparatus according to a fourth aspect of the present disclosure is based on the hot-water heating apparatus of any one of the first to third aspects of the present disclosure. The hot-water heating apparatus further includes a drive voltage detector configured to detect a drive voltage for the circulation pump. The drive voltage detector detects the drive voltage for the circulation pump at a plurality of times. The determiner determines the quantity level of the hot water circulated in the heating cycle in conformity with a change in values of the drive voltage detected at the drive voltage detector.
According to this configuration, the determiner determines the quantity level of the hot water circulated in the heating cycle in conformity with the change in values of the drive voltage detected at the drive voltage detector. In response to a decrease in the quantity of circulated hot water, the drive voltage for the circulation pump rises and the quantity of circulated hot water increases. Thus, the determiner determines the quantity level of the circulated hot water based on a degree of an increase in drive voltage. The determiner can send a result of the determined quantity level earlier.
The drive voltage for the circulation pump is directly detectable. Thus, the determiner checks the circulation pump drive voltage for an abnormal condition of the heating cycle and thereby avoids making errors such as missending a result of the determined quantity level.
A hot-water heating apparatus according to a fifth aspect of the present disclosure is based on the hot-water heating apparatus of any one of the first to fourth aspects of the present disclosure. The hot-water heating apparatus further includes a rotation rate detector configured to detect a rotation rate of the circulation pump. The rotation rate detector detects the rotation rate of the circulation pump at a plurality of times. The determiner determines the quantity level of hot water circulated in the heating cycle in conformity with a change in values of the rotation rate detected at the rotation rate detector.
According to this configuration, the determiner determines the quantity level of the hot water circulated in the heating cycle in conformity with the change in values of the rotation rate detected at the rotation rate detector. In response to a decrease in the quantity of circulated hot water, the rotation rate of the circulation pump rises and the quantity of the circulated hot water increases. Thus, the determiner determines the quantity level of the circulated hot water based on a degree of increase in rotation rate. The determiner can send a result of the determined quantity level earlier.
The rotation rate of the circulation pump is directly detectable. Thus, the determiner checks the circulation pump rotation rate for an abnormal condition of the heating cycle and thereby avoids making errors such as missending a result of the determined quantity level.
A hot-water heating apparatus according to a sixth aspect of the present disclosure is based on the hot-water heating apparatus of any one of the first to fifth aspects of the present disclosure. The hot-water heating apparatus further includes a display device. The determiner sends the result of the determined quantity level to the control terminal slave via the network before the controller shows an abnormal condition of the heating cycle on the display device.
According to this configuration, the determiner sends the result of the determined quantity level to the control terminal slave via the network. Thus, the control terminal slave can visually show a prediction about an abnormal condition of the heating cycle in a format such as a graph or a message. This configuration allows a service engineer or a user to readily check the quantity level and thus take a step before the hot-water heating apparatus stops due to an abnormal event.
An exemplary embodiment of the present disclosure will be described below with reference to the drawings. This exemplary embodiment does not intend to limit the scope of the present disclosure.

EXEMPLARY EMBODIMENT

FIG. 1 is a schematic view illustrating a hot-water heating apparatus according to the exemplary embodiment of the present disclosure. The hot-water heating apparatus according to this exemplary embodiment is configured to send and receive data via a network.
In FIG. 1, a heater includes heat pump cycle 24. In heat pump cycle 24, radiator 21 radiates heat of a high-pressure refrigerant compressed at compressor 20. The refrigerant is decompressed at decompression device 22, and then is sent to evaporator 23.
In this exemplary embodiment, the heater uses R410A refrigerant. However, the heater may use any refrigerant other than R410A refrigerant. Radiator 21 has a heat exchanger that includes stacked stainless steel plates. Radiator 21 may have a heat exchanger that includes a double copper pipe.
Circulation pump 25 sends water heated at radiator 21 to heating terminal unit 34 through supply pipe 28. Heating terminal unit 34 heats a room by dissipating heat of the hot water. Circulation pump 25 returns the water after heat dissipation to radiator 21 through return pipe 29.
In other words, hot water that gives off heat at heating terminal unit 34 is returned to radiator 21 through return pipe 29 and is heated at radiator 21 by refrigerant. The hot water is again sent to heating terminal unit 34. This circulation of the hot water constitutes a heating cycle.
After passing through heating terminal unit 34, the hot water passes through water filter 27 disposed on return pipe 29 and gets heated at radiator 21 again. Then, the hot water is sent to heating terminal unit 34 through circulation quantity detector 26 that is disposed on supply pipe 28 to detect a quantity of circulated hot water. This configuration enables the hot water to pass through circulation quantity detector 26 and water filter 27 every time the hot water circulates the heating cycle.
Thus, a decrease in the quantity of hot water circulated in the heating cycle indicates the occurrence of an abnormal event such as a clogging of water filter 27. Since determiner 42 acquires detected values of hot water circulation quantities from controller 32, determiner 42 can determine a degree of water filter 27 clogging by determining a level of the quantity of hot water circulated in the heating cycle.
The heater includes output water temperature detector 31 disposed on supply pipe 28 and input water temperature detector 30 disposed on return pipe 29. The heater allows a user to set a capacity of heating terminal unit 34 or a temperature of circulated hot water using remote controller 33.
In accordance with the set capacity of heating terminal unit 34 or the set temperature of the circulated hot water, the heater sets a target temperature to be detected at output water temperature detector 31. Controller 32 controls a rotation rate of circulation pump 25, i.e. the quantity of hot water circulated in the heating cycle, such that the difference between temperatures detected at output and input water temperature detectors 31 and 30 is a predetermined temperature difference.
In other words, if the difference between temperatures detected at output and input water temperature detectors 31 and 30 is smaller than a target difference, controller 32 controls so as to increase the rotation rate of circulation pump 25, i.e. the quantity of hot water circulated in the heating cycle.
If the difference between temperatures detected at output and input water temperature detectors 31 and 30 is larger than the target difference, controller 32 controls so as to decrease the rotation rate of circulation pump 25, i.e. the quantity of hot water circulated in the heating cycle.
Display device 41 is disposed on controller 32. Controller 32 is provided with drive voltage detector 39 and rotation rate detector 40 that are designed to respectively detect a drive voltage and a rotation rate from a motor for circulation pump 25. The exemplary embodiment described herein includes drive voltage detector 39 and rotation rate detector 40. However, the scope of the present disclosure should not be limited to this exemplary embodiment. The controller may be provided with at least one of drive voltage detector 39 and rotation rate detector 40.
Controller 32 acquires a detected level of the quantity of circulated hot water from at least one of circulation quantity detector 26, drive voltage detector 39, and rotation rate detector 40. Controller 32 sends information about the detected level to determiner 42.
After receiving the information about the detected level, determiner 42 determines the level of the quantity of circulated hot water, and sends a result of the determined quantity level to control terminal slave 38 via network 37 such as the Internet. The "result of the determined quantity level" herein includes at least one of observations, namely a decrease in the quantity of hot water circulated in the heating cycle, and a clogging of water filter 27.
This configuration enables a user or a service engineer who provides service such as replacement of water filter 27 to be notified of the result of the determined quantity level of the quantity of circulated hot water via control terminal slave 38.
Examples of control terminal master 35 include home energy management system (HEMS) controllers and wireless adapters. Examples of control terminal slave 38 include tablet terminals, cellular phones, and smartphones.
If control terminal master 35 is the HEMS controller, control terminal master 35 acts as determiner 42. If control terminal master 35 is the wireless adapter, a server capable of sending and receiving data via a network acts as determiner 42.
If control terminal master 35 acts as determiner 42, controller 32 acquires the detected level of the quantity of circulated hot water and sends information about the detected level to determiner 42. Determiner 42 determines the level of the quantity of circulated hot water and sends a result of the determined quantity level to control terminal slave 38 via network data transceiver (router) 36 and network 37.
If control terminal master 35 is a wireless adapter and if a server capable of sending and receiving data via a network acts as determiner 42, controller 32 acquires the detected level of the quantity of circulated hot water and sends information about the detected level to the server acting as determiner 42 via network data transceiver (router) 36 and network 37. Determiner 42 determines the level of the quantity of circulated hot water and sends a result of the determined quantity level to control terminal slave 38 via network 37.
As described above, the hot-water heating apparatus according to this exemplary embodiment operates as a hot-water heating system.
If a value detected by at least one of circulation quantity detector 26, drive voltage detector 39, and rotation rate detector 40 is smaller than or equal to a predetermined value, determiner 42 in the hot-water heating apparatus according to this exemplary embodiment determines that the level of the quantity of hot water circulated in the heating cycle is abnormal. In other words, determiner 42 determines that water filter 27 gets clogged and sends the result of the determined quantity level to control terminal slave 38 via network 37 before the result is shown on display device 41. This configuration enables the user or the service engineer to recognize the situation.
Control terminal slave 38 visually shows the result of the determined quantity level of the hot water circulated in the heating cycle in a format such as a graph or a message to allow the user or the service engineer to readily recognize the level of the quantity of circulated hot water. Consequently, the user or the service engineer can take a proactive step such as replacement of water filter 27 before the hot-water heating apparatus stops.
FIG. 2 is a schematic graph of an advance notice based on a quantity of hot water circulated in a heating cycle of the exemplary embodiment according to the present disclosure.
Circulation quantity detector 26 detects the quantity of hot water circulated in the heating cycle, and determiner 42 acquires the detected quantity. When determiner 42 determines that because of deposition of rust or dust of piping on water filter 27, the detected quantity gets smaller than an allowable flow rate for normal operation of the hot-water heating apparatus and has reached a predetermined quantity (a value specified for advance notice issuance), the heating apparatus sends an advance notice about clogging of water filter 27 to control terminal slave 38 via the network. The heating apparatus may send an advance notice about a decrease in the quantity of hot water circulated in the heating cycle to control terminal slave 38 via the network.
The predetermined quantity is greater than a value at which controller 32 stops the hot-water heating apparatus due to an abnormal event by a predetermined amount.
This configuration allows the service engineer to take a step such as cleaning of water filter 27, removal of clogging from the heating cycle piping, or replacement of water filter 27 before the hot-water heating apparatus stops due to an abnormal event.
FIG. 3 is a schematic graph of another advance notice based on the quantity of hot water circulated in the heating cycle according to the present exemplary embodiment.
Circulation quantity detector 26 detects the quantity of hot water circulated in the heating cycle at a plurality of times. In conformity with a change in values of the quantity detected at circulation quantity detector 26, determiner 42 determines a degree of decrease (a down slope) in the quantity of hot water circulated in the heating cycle. Before controller 32 stops the hot-water heating apparatus due to an abnormal event, the heating apparatus sends an advance notice about clogging of water filter 27 to control terminal slave 38. The heating apparatus may send an advance notice about a decrease in the quantity of hot water circulated in the heating cycle to control terminal slave 38 via the network.
Detector 26 detects the quantity of circulated hot water at ten-minute intervals, and controller 32 sends values of the detected quantity to determiner 42. Of values of the circulation quantity detected at ten-minute intervals for 24 hours, a minimum value is stored as a flow rate for the 24 hours (a period X) on determiner 42. During measurement in a next period of 24 hours (a period X+1), determiner 42 eliminates data received at ten-minute intervals for the period X. This process is repeated, and determiner 42 stores flow rates for periods of every 24 hours.
Determiner 42 analyzes the progression of the flow rate for every 24 hours based on a change in the slope of an approximate straight line for most recent three days (72 hours). If determiner 42 determines that the flow rate will reach an abnormal-stop flow rate (at which the hot-water heating apparatus stops due to an abnormal event) within 500 hours, determiner 42 sends an advance notice.
In this exemplary embodiment described above, the hot-water heating apparatus detects the quantity of circulated hot water at the plurality of times. The timing with which determiner 42 sends the notice about the decrease in the quantity of circulated hot water is not immediately before the hot-water heating apparatus stops due to an abnormal event. Determiner 42 determines a degree of decrease (a down slope) in the quantity of circulated hot water, and thereby predicts readily and precisely a right timing with which the service engineer should clean water filter 27, remove clogging from the heating cycle piping, or replace water filter 27. This configuration enables the hot-water heating apparatus to offer enhanced convenience.
Controller 32 sends data detected at circulation quantity detector 26 for the period X to determiner 42. After that, during measurement in the next period of 24 hours (the period X+1), determiner 42 eliminates data received at ten-minute intervals for the period X. This allows determiner 42 to analyze the progression of flow rates and predict a quantity level of circulated hot water while restraining an increase in cost.
FIG. 4 is a schematic graph of an advance notice based on a drive voltage for circulation pump 25 according to the present exemplary embodiment.
Drive voltage detector 39 detects the drive voltage for circulation pump 25 at a plurality of times. In conformity with a change in drive voltages detected at drive voltage detector 39, determiner 42 determines a degree of increase (an up slope) in drive voltage for circulation pump 25. Before controller 32 stops the hot-water heating apparatus due to an abnormal event, the heating apparatus sends an advance notice about clogging of water filter 27 to control terminal slave 38. The heating apparatus may send an advance notice about a decrease in the quantity of hot water circulated in the heating cycle to control terminal slave 38 via the network.
Detector 39 detects the drive voltage for circulation pump 25 at ten-minute intervals, and controller 32 sends detected drive voltages to determiner 42. Of drive voltages detected at ten-minute intervals for 24 hours, a maximum drive voltage is stored as a drive voltage for the 24 hours (a period X) on determiner 42. During measurement in a next period of 24 hours (a period X+1), determiner 42 eliminates data received at ten-minute intervals for the period X. This process is repeated, and determiner 42 stores drive voltages for periods of every 24 hours.
Determiner 42 analyzes the progression of the drive voltage for every 24 hours based on a change in the slope of an approximate straight line for most recent three days (72 hours). If determiner 42 determines that the drive voltage will reach an upper limit drive voltage (at which the hot-water heating apparatus stops due to an abnormal event) within 500 hours, determiner 42 sends an advance notice.
In this exemplary embodiment described above, the hot-water heating apparatus detects the drive voltage for circulation pump 25 at the plurality of times. The timing with which determiner 42 sends the notice about the increase in drive voltage for circulation pump 25 is not immediately before controller 32 stops the hot-water heating apparatus due to an abnormal event. Determiner 42 determines a degree of increase (an up slope) in drive voltage for circulation pump 25, and thereby predicts readily and precisely a right timing with which the service engineer should clean water filter 27, remove clogging from the heating cycle piping, or replace water filter 27. This configuration enables the hot-water heating apparatus to offer enhanced convenience.
In this exemplary embodiment, controller 32 sends data detected at drive voltage detector 39 for the period X to determiner 42. After that, during measurement in the next period of 24 hours (the period X+1), determiner 42 eliminates data received at ten-minute intervals for the period X. This allows determiner 42 to analyze the progression of drive voltages for circulation pump 25 and predict a quantity level of circulated hot water while restraining an increase in cost.
FIG. 5 is a schematic graph of an advance notice based on a rotation rate of circulation pump 25 according to the present exemplary embodiment.
Rotation rate detector 40 detects a rotation rate of circulation pump 25 at a plurality of times. In conformity with a change in rotation rates detected at rotation rate detector 40, determiner 42 determines a degree of increase (an up slope) in rotation rate of circulation pump 25. Before controller 32 stops the hot-water heating apparatus due to an abnormal event, the heating apparatus sends an advance notice about clogging of water filter 27 to control terminal slave 38. The heating apparatus may send an advance notice about a decrease in the quantity of hot water circulated in the heating cycle to control terminal slave 38 via the network.
Detector 40 detects a rotation rate of circulation pump 25 at ten-minute intervals, and controller 32 sends detected rotation rates to determiner 42. Of rotation rates detected at ten-minute intervals for 24 hours, a maximum rotation rate is stored as a pump rotation rate for the 24 hours (a period X) on determiner 42. During measurement in a next period of 24 hours (a period X+1), determiner 42 eliminates data received at ten-minute intervals for the period X. This process is repeated, and determiner 42 stores rotation rates for periods of every 24 hours.
Determiner 42 analyzes the progression of the rotation rate for every 24 hours based on a change in the slope of an approximate straight line for most recent three days (72 hours). If determiner 42 determines that the rotation rate will reach an upper limit rotation rate (a rotation rate of circulation pump 25 at which the hot-water heating apparatus stops due to an abnormal event) within 500 hours, determiner 42 sends an advance notice.
In this exemplary embodiment described above, the hot-water heating apparatus detects the rotation rate of circulation pump 25 at the plurality of times. The timing with which determiner 42 sends the notice about the increase in rotation rate of circulation pump 25 is not immediately before the hot-water heating apparatus stops due to an abnormal event. Determiner 42 determines a degree of increase (an up slope) in rotation rate of circulation pump 25, and thereby predicts readily and precisely a right timing with which the service engineer should clean water filter 27, remove clogging from the heating cycle piping, or replace water filter 27. This configuration enables the hot-water heating apparatus to offer enhanced convenience.
In this exemplary embodiment, controller 32 sends data detected at rotation rate detector 40 for the period X to determiner 42. After that, during measurement in the next period of 24 hours (the period X+1), determiner 42 eliminates data received at ten-minute intervals for the period X. This allows determiner 42 to analyze the progression of rotation rates of circulation pump 25 and predict a quantity of circulated hot water while restraining an increase in cost.
As described above, a hot-water heating apparatus according to the present disclosure can notify a control terminal slave of a result determined based on the quantity of circulated hot water via a network before the hot-water heating apparatus stops due to an abnormal event. Applications of the hot-water heating apparatus acting as a heater include hot-water heating apparatuses that run by any of heat sources such as heat pump cycles, gases, and oil.

Claims

A hot-water heating apparatus comprising:
a heater including a heat pump cycle;

a heating cycle in which hot water is circulated through the heater and a heating terminal unit, the hot water being obtained by heating water by the heater;

a circulation pump circulating the hot water in the heating cycle;

a circulation quantity detector configured to detect a quantity of the hot water circulated in the heating cycle; and

a controller,

wherein a determiner determines a quantity level of the hot water circulated in the heating cycle and sends a result of the determined quantity level to a control terminal slave via a network.
The hot-water heating apparatus according to claim 1, wherein the determiner compares the quantity detected at the circulation quantity detector with a predetermined quantity and determines the quantity level of the hot water circulated in the heating cycle.
The hot-water heating apparatus according to either claim 1 or 2, wherein
the circulation quantity detector detects the quantity of the hot water circulated in the heating cycle at a plurality of times, and
the determiner determines the quantity level of the hot water circulated in the heating cycle in conformity with a change in values of the quantity detected at the circulation quantity detector.
The hot-water heating apparatus according to any one of claims 1 to 3, further comprising
a drive voltage detector configured to detect a drive voltage for the circulation pump,
wherein
the drive voltage detector detects the drive voltage for the circulation pump at a plurality of times, and
the determiner determines the quantity level of the hot water circulated in the heating cycle in conformity with a change in values of the drive voltage detected at the drive voltage detector.
The hot-water heating apparatus according to any one of claims 1 to 4, further comprising
a rotation rate detector configured to detect a rotation rate of the circulation pump,
wherein
the rotation rate detector detects the rotation rate of the circulation pump at a plurality of times, and
the determiner determines the quantity level of the hot water circulated in the heating cycle in conformity with a change in values of the rotation rate detected at the rotation rate detector.
The hot-water heating apparatus according to any one of claims 1 to 5, further comprising
a display device,
wherein the determiner sends a result of the determined quantity level to the control terminal slave via the network before the controller shows an abnormal condition of the heating cycle on the display device.