Abstract: Hot water heating system comprising one or more water heaters with at least one water heating mechanism, and a heating-control storage tank generally configured to store heated water in a temperature stratified manner where hotter water tends to be separated from cold water. The heating-control storage tank can receive thermal energy or hot water from the water heater, send thermal energy or water to the water heater as its makeup water, and provide hot water directly to end users. The water heater may or may not be used to provide hot water to end users. The system is electronically controlled using a processor, various sensors, a recirculation pump, and electronically actuated valves. Depending on hot water needs and energy costs, the system controls water heating schedule and amount of hot water stored in the heating-control storage tank by changing system operation modes to minimize energy costs while providing reliable service.

Abstract: An electric water heater is described and wherein the bottom portion of the water holding tank is provided with various forms of electric heating elements to heat the water in the lowermost region of the tank adjacent the dome-shaped bottom wall to a temperature sufficient to prevent the proliferation of bacteria growth such as the Legionella bacteria in such lowermost region. The insulating foam support base of the water heater also provides a thermal barrier to the heating elements while biasing the heating element on the dome-shaped bottom wall in a region to insure excellent heat transfer to the cavitated zone surrounding the dome-shaped bottom wall where sedimentary deposits occur to create a culture medium for bacteria growth.

Abstract: Disclosed herein is a water heating system including a water heater having a tank, and a first temperature sensor disposed toward a top end of the tank to measure a first temperature and a second temperature sensor disposed toward a bottom end of the tank to measure a second temperature. The water heating system can further include a controller communicably coupled to the first temperature sensor and the second temperature sensor, where the controller determines an amount of heated water in the tank based on one or more algorithms and measurements made by the first and second temperature sensors.

Abstract: The disclosed technology includes a fluid heating device including a frustoconical combustion chamber and a heat exchanger that can include heating tubes. The combustion chamber can have a first end and a second end that is in fluid communication with the heating tubes. The surface area of the second end of the combustion chamber can be larger than the surface area of the first end of the combustion chamber.

Abstract: An apparatus for pre-heating potable water in aircraft with waste heat includes an air to water heat exchanger having a heat exchanger housing with an inlet end that receives heat from one or more of a galley insert exhaust air inlet, a galley appliance exhaust air inlet and an air chiller exhaust air inlet. A potable water supply inlet supplies potable water to the air to water heat exchanger, which transfers heat to the potable water, and a potable water supply outlet supplies heated potable water, such as to a galley insert or galley appliance, for example. An exhaust air outlet vents cooled exhaust air from the air to water heat exchanger.

Abstract: An apparatus and system for a combination space and water heater including a controller device and a method for control. The controller device is a self-contained system that can be added to, or in combination with, existing water heaters and hydronic air heating systems using standard plumbing connections, and provides a potable water system without any need of an intermediary heat exchanger. The controller device automatically monitors a heating capacity of the water heater and the hydronic heating coil over time, and correlates measured heating loads with one or more environmental temperatures, thermostats, user settings, and/or a supplemental heating system.

Abstract: A water heater system includes a primary heat exchanger including a tank and at least one flue, and a secondary heat exchanger including a core and a flue gas flow path. The water heater is operable in a heating mode in which a combustor produces hot flue gas and a water pump flows water through the core of the secondary heat exchanger and into the tank, and in a non-heating mode in which the combustor and the water pump are inoperative. The flue gas flows from the combustor through the at least one flue to heat the water in the tank and then through the flue gas flow path to heat water in the core before being exhausted.

Abstract: An electric water heater is described and wherein the bottom portion of the water holding tank is provided with various forms of electric heating elements to heat the water in the lowermost region of the tank adjacent the dome-shaped bottom wall to a temperature sufficient to prevent the proliferation of bacteria growth such as the Legionella bacteria in such lowermost region. The insulating foam support base of the water heater also provides a thermal barrier to the heating elements while biasing the heating element on the dome-shaped bottom wall in a region to insure excellent heat transfer to the cavitated zone surrounding the dome-shaped bottom wall where sedimentary deposits occur to create a culture medium for bacteria growth. In one embodiment a heating wire transfers heat to the lowermost region from the lower end of the surrounding side wall of the tank and access to the heating wire is provided for connection and removal thereof.

Abstract: A blower assembly is attached to a water heater having an exhaust opening, the assembly includes a tank cap attached to a tank of the heater. A recess surface formed in the exterior surface of the cap. A member has a first surface that is connected to the tank cap to form a cover plenum between the cap and the member. The blower includes a motor, an air moving member connected to the motor and a blower housing having an interior containing the fan. The blower housing has an input opening that communicates the blower housing interior with the member output opening. The blower housing, the member and the tank cap provide an exhaust gas flow path from the exhaust opening of the heater through the cover plenum, through the blower housing interior and out the output opening.

Abstract: A water heating system can include a water heater having a tank, an inlet line, and an outlet line, where the inlet line provides unheated water to the tank, and where the outlet line draws heated water from the tank. The water heating system can also include multiple sensing devices, where each sensing device of the plurality of sensing devices measures a parameter associated with the tank. The water heating system can further include a controller communicably coupled to the plurality of sensing devices, where the controller determines an amount of heated water in the tank based on measurements made by the plurality of sensing devices.

Abstract: A water heater having a casing (100) in which a burner body (1) and a fan case (2) are accommodated, wherein the burner body (1) includes a main burner body unit (12) having a flat burner (3) on a lower surface thereof, and an introducing unit (11) projected from an upper surface of the main burner body unit (12), wherein the introducing unit (11) has an inlet port (10) communicated with the fan case (2), and an fan installation surface (13) having the inlet port (10) is provided so as to face to a front direction or a diagonally front direction as viewed from a frontward direction.

Abstract: A method and an apparatus is described for preventing bacteria proliferation in a bottom end of a water holding tank of an electric water heater. Different water convection devices are described for convecting heated water from inside the tank and into the bottom end of the tank to raise the temperature at the bottom end sufficiently high to prevent bacteria growth and particularly at a temperature of at least 46 degrees C. where the Legionella bacteria can not survive. The temperature at the bottom end of the tank is monitored and the convection devices controlled to maintain the desired hot water temperature. An added benefit of the invention is that it also prevents sediment deposits and water temperature stratification in the tank bottom end section.

Abstract: A method and an apparatus is described for preventing bacteria proliferation in a bottom end of a water holding tank of an electric water heater. Different water convection devices are described for convecting heated water from inside the tank and into the bottom end of the tank to raise the temperature at the bottom end sufficiently high to prevent bacteria growth and particularly at a temperature of at least 46 degrees C. where the Legionella bacteria can not survive. The temperature at the bottom end of the tank is monitored and the convection devices controlled to maintain the desired hot water temperature. An added benefit of the invention is that it also prevents sediment deposits and water temperature stratification in the tank bottom end section.

Abstract: A gaseous fuel-air-flue gas burner is described herein. One device includes a housing having a combustion chamber containing a combustion area in which a combination of fuel, air, and flue gas mix to form a flame, a flame arrester having an outer surface for the flame to form, a supply chamber configured to receive the fuel, air, and flue gas mixture at an inlet and provide the combustion area with the fuel, air, and flue gas mixture at an outlet to produce a flame and a quantity of return flue gas, and a return cavity configured to move return flue gas away from the combustion area and into the inlet of the supply chamber.

Abstract: A method for buffering thermal energy comprises a thermal buffering medium contained by a thermal energy buffer. The volume of the thermal buffering medium is subdivided in one or more parts such that the different parts of the volume of the thermal buffering medium together form the total thermal buffering medium. The thermal energy buffer comprises a temperature sensor for each part. A controller has at least one signal representing at least one thermal energy value related to the thermal energy buffer. The thermal energy values comprise a predetermined minimum amount of thermal energy present in the thermal energy buffer. The controller controls a heater such that the amount of thermal energy present in the thermal energy buffer is higher than or equals the predetermined minimum amount of energy present in the thermal energy buffer.

Abstract: Disclosed is a water heater that has a water storage tank, a first pass flue tube extending from a top of the water storage tank to a bottom of the water storage tank, a down-fired burner assembly positioned to direct combustion gases into the first pass flue tube, a plurality of second pass flue tubes extending from the bottom of the water storage tank to a top of the water storage tank, and an expansion chamber positioned below the bottom of the water storage tank. The expansion chamber receives the combustion gases from the first pass flue tube and delivers the combustion gases to the second pass flue tubes. The water heater operates with a non-positive vent static pressure and with a vent gas temperature that avoids or reduces excessive condensate production in an exhaust vent connected to receive combustion gases from the water heater.

Abstract: A circulating-type hot-water supply device (1) is provided with a heat exchanger abnormality determining unit (62), which inhibits execution of a suitable temperature maintaining operation when the suitable temperature maintaining operation continued for a predetermined time or more and stops a circulating pump (25), and when a temperature rise range of a detected temperature of a heat exchanger outlet temperature sensor (2) after stopping the circulating pump (25) becomes equal to or more than a temperature rise threshold value determined according to a selected state of burner blocks (3a),(3b) in a combusted state immediately before stopping the circulating pump (25), determines that a heat exchanger is in an abnormal state.

Abstract: A water heater includes a bypass that is formed, on the side of a water supply pipe, branching from a main water path and bypassing a part of the main water path, and a flow path switching unit (a valve and a stepping motor) that is formed at a branching portion of the main water path and the bypass. The flow path switching unit is controlled by a controller and that can selectively switch a flow path between the main water path and the bypass. A microbubble generator generating microbubbles is provided on the bypass, the microbubble generator including a water agitator portion, a compression portion and a decompression portion. When the controller determines that scale has built up, the flow path is switched to the bypass by the flow path switching unit, and water containing microbubbles is caused to flow inside the water heater.

Abstract: When a detection temperature by a hot-water tank thermister (42) has been equal to or lower than a re-heating determination temperature over at least a re-heating determination time, a tank controller (50) performs a sterilization process by heating hot water within a hot-water tank (30) by means of a heat pump unit (60); and when the detection temperature by the hot-water tank thermister (42) has been equal to or lower than a determination temperature for prohibiting the use of hot water in the hot-water tank over at least a determination time for prohibiting the use of hot water in the hot-water tank, the tank controller (50) performs only a temperature regulation control via heating while keeping a hot-water flow regulation valve (34) in a closed state.

Abstract: An integrated water heating system is comprised of a hot water holding tank having an outer jacket secured in spaced relationship therearound. An insulating space is defined about the hot water holding tank and the outer jacket. A connecting bracket is secured to an outer surface of the hot water holding tank and has a projecting formation provided with an arcuate connecting wall spaced a predetermined distance from the outer surface for close fit adjacent an inner surface of the outer jacket and disposed for alignment with an external support bracket adapted to be secured thereto through the outer jacket. Thermal insulating material is disposed in the insulating space and about the connecting bracket. An external water heating device is removably supported by the external support bracket. A pump circulates water through the water heating device and through the hot water holding tank.

Abstract: A fuel-fired water heater is shut down when a predicted steady state combustion chamber temperature is below a known threshold. The predicted steady state temperature is based on combustion chamber temperatures during heat up of the burner and appliance.

Abstract: Methods and systems for operating a water heater to limit the effects of stacking in a water heater tank are disclosed. In some cases, the water heater controller may determine a rate of change of the water temperature in the water heater tank. If the rate of change exceeds a threshold value, the controller may adjust the water heater temperature set point downward to help reduce stacking in the water heater. In some cases, the water heater temperature set point may be returned to the original water heater temperature set point when stacking is no longer likely to be of a concern. In one illustrative embodiment, the controller may track the time that the heater of the water heater is in the “on” state, or the time that the heater is in the “off” state, during subsequent heating cycles. The controller may then compare the “on” time or the “off” time to respective recovery threshold times.

Abstract: A water heater having a water tank and a heating source disposed proximate to the water tank such that the heating source may heat water within the water tank. A temperature sensor is provided that is partially thermally isolated from the water in the water tank. A controller may be provided that at least partially compensates for the partial thermal isolation of the temperature sensor and regulates the heating source. In some instances, the temperature sensor may be at least partially disposed within a thermally isolating mass.

Abstract: A self-powered combustion control system having a burner and a fuel supply control valve connected with the burner. The fuel supply control valve includes ignition and hold solenoids arranged whereby energizing the ignition solenoid causes the hold solenoid to transform from a closed disposition in which no fuel passes to the burner to an open disposition in which fuel flow to the burner is initiated for igniting the burner and subsequently maintained during heating of the material to be heated. An electronic system controller is provided for controlling the ignition solenoid and an unpowered rechargeable energy storage device is provided for all of the power required to operate the combustion control system.

Abstract: A gas control valve includes a base, a stop device, a driving device. The base has a gas passageway therein for gas to flow therethrough. The stop device is provided in the base to be moved between a first position, in which the stop device narrows the gas passageway to allow a first gas flow flowing through the base, and a second position, in which the stop device allows a second gas flow flowing through the base, wherein the second gas flow is greater than the first gas flow. The driving device is controllable to move the stop device between the first position and the second position. Therefore, the gas control valve of the present invention may adjust the gas flow.

Abstract: Exemplary embodiments are disclosed of valves and controllers for water heaters. Also disclosed are mounting methods for valves and controllers for water heaters. In an exemplary embodiment, a gas valve and controller are mounted to and/or located at a burner door of a water heater.

Abstract: A rapid recovery tankless water heater operates by means of an electronic controller or card that regulates the operation of each of the system components, thereby optimizing gas consumption and minimizing the emission of gas pollutants. A multi-burner only ignites when certain conditions or predefined requirements in the electronic controller logic are met. Other factors contributing to improved water heater efficiency are: a) the water tank design which at the bottom has a water chamber surrounding the combustion chamber, and b) the use of a finned heat exchanger, which together with a core, successfully utilizes most of the thermal energy contained in the combustion gases. An air deflector device stops the entry of air currents at the top of the heater, thus stopping potential flame reversing and even flame extinction in the multi-burner.

Abstract: A process for conserving energy while operating a water heater includes the steps of programming a system controller with at least one time interval and assigning a target temperature, comparing the current time to the programmed time interval and the current water temperature setting for the water heater against the target temperature, and heating the water as long as the current time is within the time interval and the water temperature setting is less than the target temperature. An energy saving switch includes a programmable logic controller, geared control shafts, a motor, a control lever, and a mating cuff. Together, these members control the water heater thermostat control valve to ensure that hot water is available only during the times of day when it is required.

Abstract: A water heater may be configured to temporarily increase its hot water capacity by heating water to a higher boost temperature. In some instances, the water heater may include a main controller that can accept a boost request from a remote controller, and thus may temporarily provide additional hot water capacity without, for example, requiring a homeowner to go down to the basement, out to the garage, or wherever the water heater happens to be to make manual adjustments to the water heater settings.

Abstract: A fluid system is provided comprising: a heater having an inlet and an outlet; a storage vessel; storage vessel heating means for heating the fluid in the storage vessel; a mixing valve having a first inlet for receiving fluid to be heated from a fluid supply, a second inlet for receiving fluid from the storage vessel, and an outlet for supplying fluid to the inlet of the heater; and a controller wherein the controller is arranged to monitor the heater's performance and to operate the mixing valve to blend the fluid from the fluid supply with fluid from the storage vessel, for example, when a demand on the heater exceeds a threshold value.

Abstract: An energy conservation system to selectively control the operation of the heating elements of a water heater including a water storage tank operable in an automated mode to control the temperature of water within the water storage tank comprising a flow detector such as temperature sensor to sense the inlet or outlet water temperature to detect a change in temperature measured in time and duration and a tank temperature to sense the water temperature within the storage tank and generate corresponding temperature signals and a microprocessor coupled to the flow detector and tank temperature sensor to receive the corresponding signals including means to determine when there is a demand for hot water and means to determine a pattern of hot water usage over a water usage cycle to maintain the water in the water storage tank at a minimum temperature to supply a minimum quantity of hot water and increase the temperature of the water to a maximum temperature to supply a maximum quantity of hot water corresponding to

Abstract: Hot water heater system (such as, for example, a gas-powered hot water heater system) that includes a self-powered automatic pilot light and which is not connected to any external source of electrical power.

Abstract: A storage type water heater, which may have either fuel or electric-based heating apparatus, is provided with a control system incorporating a control algorithm that monitors the time between heat demands and then sets the tank water setpoint temperature accordingly to lower the effects of water stratification due to periodic heat demands, and also save energy. When the time between consecutive heat demands is less than a predetermined setback time, for a number of heat demands equal to a predetermined setback limit, a setback mode is activated and responsively operates to reduce the setpoint temperature by a predetermined setback offset at the next cycle. The original control setpoint temperature is restored once the time between two successive heat demands is more than the setback time.

Abstract: Methods and systems for operating a water heater to limit the effects of stacking in a water heater tank are disclosed. In some cases, the water heater controller may determine a rate of change of the water temperature in the water heater tank. If the rate of change exceeds a threshold value, the controller may adjust the water heater temperature set point downward to help reduce stacking in the water heater. In some cases, the water heater temperature set point may be returned to the original water heater temperature set point when stacking is no longer likely to be of a concern. In one illustrative embodiment, the controller may track the time that the heater of the water heater is in the “on” state, or the time that the heater is in the “off” state, during subsequent heating cycles. The controller may then compare the “on” time or the “off” time to respective recovery threshold times.

Abstract: A hot water supply apparatus including: a hot-water supply pipe for guiding hot water generated by a hot-water generator to a hot-water supplying terminal; two hot-water supply temperature sensors for detecting water temperature in the hot-water supply pipe; a temperature control unit for adjusting a temperature of the hot water supplied to the hot-water supplying terminal; a sensor abnormality determining unit for determining sensor abnormality when a difference between temperatures detected by the two hot-water supply temperature sensors is larger than a predetermined permissible error; a sensor selector for selectively setting one hot-water supply temperature sensor detecting a higher temperature as a hot-water supply temperature sensor for temperature control; and a hot-water supply temperature controller for controlling the temperature control unit so that a temperature detected by the hot-water supply temperature sensor for temperature control selected from the two hot-water supply temperature sensors i

Abstract: A fuel-fired water heater is shut down when a predicted steady state combustion chamber temperature is below a known threshold.

Abstract: The present invention relates to a firewood boiler, comprising: a boiler main body including a feeding hole through which wood fuel and air for combustion are fed, a smoke exhaust hole defined in the top thereof so as to be connected to an exhaust pipe, an air inlet defined adjacent to the smoke exhaust hole, and a heating-water store in which heating water is stored; a main opening/closing unit installed on the boiler main body to open and close the feeding hole and selectively supply and block the entry of outside air into the boiler main body when the feeding hole is closed; an auxiliary opening/closing unit for supplying outside air into the boiler main body when the entry of outside air is blocked by the main opening/closing unit; a temperature sensor for sensing the temperature of the heating water; and a control unit for controlling the inflow and blocking of air by means of the main opening/closing unit on the basis of information on the temperature sensed by the temperature sensor.

Abstract: A method for examining water heater safety includes the steps of: setting a desired temperature and sensing a cold water temperature and a flow rate of water to calculate a theoretical gas consumption, and then supplying a combustor the theoretical gas consumption to heat water; sensing a hot water temperature, and calculating a temperature ratio by the desired temperature, the cold water temperature and the hot water temperature. Examining the temperature ratio may find that the water heater is abnormal or malfunctioning. An efficiency ratio may also be calculated by the theoretical gas consumption and the actual gas consumption. Examining the efficiency ratio may find that the water heater is abnormal or malfunctioning as well.

Abstract: A fuel-fired appliance is shut down when a predicted steady state combustion chamber temperature is below a known threshold. The predicted steady state temperature is based on combustion chamber temperatures during heat up of the burner and appliance.

Abstract: A hot water storage type hot water supply device is capable of heating water inside a hot water storage tank appropriately, thereby preventing energy waste. A circulating pump is operated and a burner is incinerated, when the average of detected temperatures from water temperature detectors falls below a predetermined lower limit temperature. The burner is extinguished when an accumulated heating amount from the beginning of operation of a heat source equipment becomes equal to or more than a target heating amount necessary for elevating the total amount of water in the hot water storage tank to a preset hot water delivery temperature. The circulating pump is continuously operated after extinguishing the burner, until an accumulated circulated water amount of a circulating path becomes equal to or more than a predetermined water amount set to be equal to or more than a capacity of the hot water storage tank.

Abstract: Methods and systems for operating a water heater to limit the effects of stacking in a water heater tank are disclosed. In some cases, the water heater controller may determine a rate of change of the water temperature in the water heater tank. If the rate of change exceeds a threshold value, the controller may adjust the water heater temperature set point downward to help reduce stacking in the water heater. In some cases, the water heater temperature set point may be returned to the original water heater temperature set point when stacking is no longer likely to be of a concern. In one illustrative embodiment, the controller may track the time that the heater of the water heater is in the “on” state, or the time that the heater is in the “off” state, during subsequent heating cycles. The controller may then compare the “on” time or the “off” time to respective recovery threshold times.

Abstract: A control system for a water heater generally includes a water heater controller configured to receive upper and lower sensor temperatures associated with water in the respective upper and lower portions of the tank. The water heater controller is configured to determine a value indicative of a portion of water in the tank at a desired set-point temperature as a function of the upper sensor temperature, the lower sensor temperature, and the desired set-point temperature. The water heater controller is configured to wirelessly transmit at least one signal indicative of said value indicative of the portion of water in the tank at the desired set-point temperature. A user interface includes a plurality of selectively illuminated segmented portions. The user interface is configured to receive said value from the water heater controller and to selectively illuminate a number of segmented portions representative of said value.

Abstract: A mounting bracket for mounting a temperature sensor, a gas valve, a power delivery unit, a controller and/or any other suitable object or device to a water heater tank. An illustrative but non-limiting example may be found in a mounting bracket that includes a polymeric body that has a sensor portion configured to receive a temperature sensor. The sensor portion may have a distal end that extends into and supports the temperature sensor within the water heater tank. The polymeric body may also includes a threaded portion that is configured to threadably engage a threaded spud in a water heater tank such that the distal end of the sensor portion extends into the water tank of the water heater.

Abstract: A control system is provided for a modulated heating system including at least one modulating water heater and a controller. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater. Condensation of flue gas products is prevented by monitoring flue exhaust temperature for each heater and controlling the modulation of each heater to maintain a minimum heater output sufficiently high to prevent condensation of flue gas products from that heater. Rapid reaction to changes in system heat demand is provided by sensing changes in flow rate in a primary loop of the system and anticipating resulting changes in temperature thus allowing for change in heater output prior to the time the change in flow rate has fully impacted system temperature.

Abstract: A method of controlling a modulating water heater supplying water to a system includes sensing a parameter which changes corresponding to a change in system flow rate, the sensed parameter being a parameter other than system temperature, and then modulating output of the heater in response to a change in the sensed parameter. Early detection of system flow rate changes permits early modulation of water heater output before the changes in flow rate have had time to significantly impact the system temperature.

Abstract: A control for a water heater is provided that comprises a pressure switch for sensing a predetermined level of airflow sufficient for maintaining proper burner operation, and a temperature sensing means for sensing the temperature of the water in the tank. The control further comprises a processor for controlling the operation of the burner to maintain the water temperature above a predetermined value. When the processor receives a signal from the pressure switch or temperature switch indicating a malfunction, the processor shuts down the burner and subsequently attempts to restart the burner. The processor will lock-out further burner operation after a predetermined number of consecutive shut downs occurs, and will communicate any malfunction information to a remote display device.

Abstract: A water heater including a water inlet line having an inlet opening that introduces cold water to a tank, a water outlet line having an outlet opening that withdraws heated water from the tank, and a heating element. The water heater further includes a control circuit. The heating element can be an electrical resistance heating element, a gas heating element, or a combination thereof. In one construction, the gas heating element includes a first combustive section and a second combustive section separately controlled from the first combustive section.

Abstract: A temperature controlling device includes a setting controller, a gas valve, a burner, an inlet temperature sensor, a water meter, and an operational controller. User sets a desired temperature via the setting controller. The inlet temperature sensor senses an inlet temperature of water at an inlet of a pipe, and then operational controller calculates a difference between the inlet temperature and the desired temperature to get a total heat for heating water in a predetermined heating time and transfer the total heat into a total gas consumption, and controls the gas valve to supply gas to the burner with an amount of the total gas consumption in a predetermined heating time. After that, water should be heated to the desired temperature, and the operational controller controls the gas valve to decrease the gas supply for maintaining water temperature.

Abstract: A boiler system has a boiler and a combustion amount control unit. The boiler includes a boiler body, a discharge unit, a discharge passage, a feedwater preheater and a feedwater temperature measuring unit. The feedwater preheater includes a heat exchanger. The feedwater temperature measuring unit measures a feedwater temperature that is the temperature of the feedwater flowing in the heat exchanger. The combustion amount control unit controls combustion amount in the boiler, and has a feedwater temperature threshold as a threshold relating to the feedwater temperature. The combustion amount control unit minimizes the combustion amount in the boiler in a case where the feedwater temperature measured by the feedwater temperature measuring unit is the feedwater temperature threshold or lower.

Abstract: A water heater is provided with monitor/diagnostic display apparatus that selectively provides a user with visual or other type of indicia of the overall efficiency of the water heater. The apparatus includes a monitoring unit that may be mounted on the water heater, and a display unit that may be mounted either on the water heater or remotely therefrom.