Abstract: Provided is a condensate water trap for a gas furnace that collects and discharges condensate water produced in a heat exchanger and an exhaust pipe. The condensate water trap includes: a first inlet through which the condensate water produced in the heat exchanger is introduced; a second inlet through which the condensate water produced in the exhaust pipe is introduced; a first flow path through which the condensate water coming from the first inlet passes; a second flow path through which the condensate water coming from the second inlet passes; an outlet through which the condensate water introduced through the first and second inlets is discharged; a third flow path into which the residual condensate water passed through at least one of the first and second flow paths but not discharged through the outlet is introduced; and a sensing mechanism that senses if the amount of residual condensate water introduced into the third flow path is greater than or equal to a given amount.

Abstract: The present invention provides a combined heating and hot-water boiler for heating and hot-water. The combined heating and hot-water boiler comprises: a main heat exchanger which heats heating water through heat exchange; a hot-water heat exchanger to which the heating water heated by the main heat exchanger is supplied, and which heats tap water into hot water through heat exchange with the heating water; and a control unit which controls the flow of the heating water having passed through the hot-water heat exchanger to control the formation of at least one of a first flow path for supplying, to an object to be heated, the heating water having passed through the hot-water heat exchanger, and a second flow path for supplying, to the main heat exchanger, the heating water having passed through the hot-water heat exchanger.

Abstract: A conduit fitting for an exhaust duct includes a conduit and a condensate trap. The conduit fitting defines an interior space partitioned into an upper conduit and a lower condensate reservoir. The condensate reservoir can be configured to contain a neutralizing agent for neutralizing acidic condensate prior to it exiting the reservoir.

Abstract: A heat pump water heater includes a tank, a first condenser, a second condenser, a heat pump, valving and a controller. The tank includes an interior cavity, an input port and an output port. The first condenser and second condenser each include an input port and an output port. The heat pump drives a fluid in a heated state through an output. A first setting of the valving fluidically couples the heat pump output to the input port of the first condenser, and fluidically disconnects the heat pump output from the input port of the second condenser. A second setting of the valving fluidically couples the heat pump output to the input port of the second condenser, and fluidically disconnects the heat pump output from the input port of the first condenser. The controller selectively directs the valving to the first or second setting.

Abstract: Disclosed is a vehicle-mounted gas water heater, wherein the water flow pipe comprises a water inflow section, a first heating section, a second heating section and a water outflow section, wherein the water inflow section is shortened, wherein the water inflow section is shortened, a heating section is rapidly heated directly by the combustion heating device, and the second heating section is heated by winding on the heat exchanger, so that, formation of condensed water at the water inflow section is reduced due to reduction of surface area, condensed water formed on the surface of the first heating section is rapidly evaporated, and it is difficult for condensed water to form on the surfaces of the second heating section and the outflow section.

Abstract: A system for heating water to improve safety and efficiency. The system may have normal operation measured in time. After a time of normal operation, a water temperature setpoint may be checked. If the setpoint is not at a certain level, normal operation may continue. If the setpoint is within the certain level, water temperature may be measured. If the water temperature is less than a desired level, one or more draws of water may be measured for a preset temperature drop. If the draws do not meet the temperature drop, a return to check the setpoint may be made. If the draws meet the temperature drop, the setpoint may be reduced and a time of normal operation may be measured to determine whether a burn cycle occurs within the time. If not, normal operation may continue; but if so, a return to check the setpoint may be made.

Abstract: A system to reduce standby losses in a hot water heater is presented. The system utilizes a dual safety relay valve between the combination gas controller and the burner. The dual safety relay valve bypasses gas to a rotary damper actuator valve to position a damper flapper valve located over/inside the flue pipe. Once the flapper valve has opened to ensure combustion, the gas is allowed to flow back to the dual safety relay valve. Some of the bypass gas may be diverted to boost the pilot or to supply a booster. The dual safety relay valve is then opened to allow the gas supply to the burner. Once the burner is turned off, bypass gas bleeds out of the rotary damper actuator valve to close the damper flapper valve to reduce standby losses through the flue pipe, and to allow the dual safety relay valve to close tightly.

Abstract: An on-demand high volume capable fluid heating system for supplying a total heating power at a turndown ratio and a total flowrate of a fluid supply, the fluid heating system comprising a plurality of heat exchangers fluidly connected in parallel, each of the plurality of heat exchangers comprising: a fluid conductor, wherein each of the plurality of heat exchangers contributes to the total heating power and a portion of the total flowrate of the fluid supply through the fluid conductor; an inlet conductor configured to connect the fluid supply to the plurality of heat exchangers; an outlet conductor configured for receiving the fluid supply downstream of the plurality of heat exchangers; an auxiliary conductor connecting the inlet conductor at a first location and the outlet conductor, the auxiliary conductor comprising a modulating valve; and a pump disposed downstream from the first location on the inlet conductor.

Abstract: A water purifier includes a working coil, a hot water tank that faces toward the working coil and is spaced apart from the working coil by a gap to heat a liquid passing through an inner space of the hot water tank by an induction of the working coil, a bracket that is coupled to the hot water tank, the working coil being located between the hot water tank and the bracket, and a spacer that is located between the working coil and the hot water tank to thereby define the gap between the working coil and the hot water tank.

Abstract: A heating device, including at least one heating unit, which is configured to heat at least one fluid; at least one fluid supply line, which is provided for supplying the fluid to the heating unit for heating; at least one fluid discharge line, which is provided for discharging the fluid from the heating unit after the heating; and a control and/or regulating unit, which is configured to operate the heating unit in a pulsed manner, in at least one operating state, in order to set a particular temperature. The heating device includes a valve unit, which is configured to mix the fluid in the fluid discharge line with fluid from the fluid supply line, upstream from an outlet.

Abstract: The disclosure provides a heating and hot water supply apparatus which includes a heating circulation path configured to circulate a heated heating medium with a heating terminal, and a bypass path branched from the heating circulation path for causing the heating medium to flow therethrough without passing through the heating terminal. A hot water supply heat exchanger is disposed in the bypass path. A division ratio of the heating medium from the heating circulation path to the bypass path is controlled by a distribution valve. The division ratio is increased from a first value to a second value when a reservation preheat control is started during the heating operation according to a start reservation time of hot water supply operation reserved by a timer, and set to a third value greater than the second value during a simultaneous operation of the hot water supply and the heating operation.

Abstract: Provided is a refrigeration cycle apparatus configured to perform a heating operation and a simultaneous heating and hot-water supply operation. The refrigeration cycle apparatus is configured to execute an operation mode circulating refrigerant through, in order, a discharge outlet of a compressor, a first heat exchanger, an expansion device, a second heat exchanger provided to a water tank, and a suction inlet of the compressor, and causing the refrigerant flowing through the second heat exchanger to evaporate by heat generated by a heat source provided to the water tank.

Abstract: A hot water supply system that can reduce energy consumption is provided. The hot water supply system includes a liquid heater for heating a liquid, a liquid-water heat exchanger, a water-heating circuit in which the liquid is circulated between the liquid heater and the liquid-water heat exchanger, a lower outward path for leading water from a lower part of a hot water storage tank to the liquid-water heat exchanger, the upper return path for leading the water from the liquid-water heat exchanger to an upper part of the hot water storage tank, a middle outward path for leading the water from a middle part of the hot water storage tank to the liquid-water heat exchanger, a middle return path for leading the water from the liquid-water heat exchanger to a middle part of the hot water storage tank.

Abstract: A device for controlling a water heater comprises a touch interface containing five water temperature modes; a capacitive touch unit including a touch sensing circuit, wherein the capacitive touch unit is configured to the touch interface for sensing user touch; a controller connected to the capacitive touch unit, wherein the controller is configured to switch at once among five water temperature modes according to preset sequence when touch interface senses user touch and sends touch signal; wherein one of five-water temperature modes comprises a water temperature without heating function each of remaining four water temperature modes corresponds to temperature range, and temperature range of two adjacent water temperature modes has certain overlaps.

Abstract: A washer fluid heating device includes a container that contains a washer fluid, a lid portion attached to a first end of the container in a direction of a central axis to face an accommodation space for the washer fluid, a heating unit that has a proximal end portion attached to the lid portion and extends toward the accommodation space, and an outflow pipe disposed in the accommodation space to allow the washer fluid in the accommodation space to flow out. The outflow pipe includes a first outlet provided at a position between a second end opposite to the first end of the container and the heating unit, the position being separated from the second end, and a second outlet provided at a position between a side wall of the container and the heating unit, the position being separated from the side wall.

Abstract: A heat exchanger having a cylindrical body comprising an upper section, a lower section, a side water jacket surrounding the upper and lower sections, a top water jacket disposed atop the upper section and a gas exhaust disposed below the lower section. A water cavity is disposed substantially in the lower section while a gas cavity having a burner is disposed substantially centrally within the gas cavity. A plurality of water tubes disposed in a ring formation, connect the water cavity through the gas cavity to the top water jacket and a plurality of gas tubes also disposed in ring formations, connect the gas cavity through the water cavity to the gas exhaust. At least one of the gas tubes ring has a diameter that is greater than that of the water tubes ring.

Abstract: A water heater appliance and method for operating a water heater appliance are provided. The method includes measuring a temperature of water within the water heater appliance, operating a heating element of the water heater appliance if the temperature of water within the water heater appliance is less than a threshold temperature and deactivating the heating element of the water heater appliance when the temperature of water within the water heater appliance exceeds the threshold temperature.

Abstract: A conversion factor learning unit successively updates a temperature conversion factor by learning a performance ratio of an output heat quantity with respect to an input scale number corresponding to a requested heat quantity generation to a hot water supply apparatus. The temperature conversion factor learned by the conversion factor learning unit is reflected in arithmetic operation of an FF scale number by a feedforward control unit and arithmetic operation of the FB scale number by the feedback control unit. An integral control in the feedback control unit is preferably turned off.

Abstract: A heating mat for a condensate trap can include resistive traces which heat the mat. The mat can be adhered to the condensate trap, for example using pressure sensitive adhesive. A control thermostat monitors an ambient temperature and/or a temperature within the condensate trap. If a temperature is at or above a setpoint, the controller thermostat disables power to the resistive traces. If a temperature is below at or below a setpoint, the controller thermostat enables power to the resistive traces to heat the condensate trap and the condensate within the condensate trap. In an embodiment, the heating mat can operate at a voltage supplied by the furnace or from a power source external to the furnace.

Abstract: A gas boiler and a method of adjusting output of the gas boiler by adjusting mixture ratio of air and gas for combustion in proportion to an output value of the boiler, and continuously changing the mixture regardless of the boiler output. The gas boiler includes a ventilator, a gas valve, a burner, a combustion chamber, a heat exchanger, and an exhaust gas hood. The inlet of the ventilator includes an output adjusting device having an air inlet; an air adjustment valve; a gas outlet; a gas adjustment valve that adjusts the gas passing through the gas outlet; and a valve driving unit that drives the air adjustment valve and the gas adjustment valve. Output of the burner is continuously adjusted by adjusting distance between the air adjustment valve and the gas adjustment valve, and distance between the air inlet and the gas outlet.

Abstract: A hot water supply system provided on a water pipeline, which includes a water inflow side and a water outlet side. The hot water supply system includes a plurality of water heaters; each includes a conduit, a heating device, a calculating unit, and a control unit. The conduit includes an inlet section, an outlet section, and a heating section in sequence, wherein the inlet section and the outlet section are connected with the water inflow side and the water outflow side respectively; the heating device heats the heating section; the calculating unit estimates a heating workload needed. If the heating workload of any water heater exceeds a predetermined upper limit workload thereof, the control unit of one water heater controls the other idle heating device to heat water, which ensures that water temperature of water provided to the water outflow side would reach a demanded water temperature.

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 (31) 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 stored hot water over at least a determination time for prohibiting the use of stored hot water, 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: 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: A method of controlling a water heater is provided. The method comprises evaluating the fitness of solutions associated with a plurality of individuals in a population for a current operating environment of the water heater. Each of the plurality of individuals comprises a dominant genotype and a recessive genotype. Each genotype represents a solution for controlling the water heater. A fitness function is applied to the dominant genotype of each individual. The fitness function is based on at least one of water flow demand data and energy price data. The method further comprises storing previously encountered genotypes in the recessive genotypes of the individuals. The method further comprises selecting a solution for controlling operation of the water heater based on the fitness evaluation.

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 on demand tankless water heater system that is capable of quickly delivering water within a desired temperature range. The tankless water heater provides a hybrid heating method that contains a primary heating system and a secondary heating system disposed in a buffer tank that cooperate to facilitate control of output water temperature during water usage. A pressure differential switch detects low flow demand and allows the secondary heating system to provide immediate heating to the water. This secondary heating system provides a faster temperature response and fine tuning of output water temperature.

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: A water heater appliance and a method for operating the same are provided. The method includes receiving a first temperature measurement from a temperature sensor of the water heater appliance, receiving a second temperature measurement from the temperature sensor of the water heater appliance, and establishing if water is flowing through a conduit of the water heater appliance based at least in part on the first and second temperature measurements.

Abstract: The invention provides a method for producing a supply of a heated fluid, which method comprises passing the fluid through a heat exchanger unit where it is heated by a heat source; characterised in that the heat source derives heat from the exothermic reaction of two or more chemical reactants. The chemical reactants are preferably an acid and a base.

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: 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 method for controlling a boiler includes firing a boiler, and monitoring a temperature deviation between a boiler temperature and a heating temperature profile over time. If the temperature deviation exceeds an allowable deviation, the boiler is shut off.

Abstract: A method for detecting and compensating for sediment build-up in a tank style water heater is disclosed. An illustrative but non-limiting example may include monitoring a temperature of water within a water storage tank of a water heater over time, resulting in a monitored temperature profile. The method may then include determining if the monitored temperature profile includes one or more features that indicate sediment build up in the water storage tank, and if so, provide an output that indicates sediment build up is present.

Abstract: The present invention relates to a combustion control device incorporated in an apparatus such as water heater and provides the combustion control device having an improved configuration with a main controller and a sub controller, capable of employing a microcomputer with lower capability as the sub controller, and ensuring higher safety than ever before. Signals indicating a combustion state of a combustion apparatus are inputted into the main controller 35 and the sub controller 36 in parallel. Upon fulfillment of a predetermined condition of stopping, the main and sub controllers 35 and 36 each output a stop signal to cut off a current to be supplied to a device driving circuit 42. The conditions of stopping in outputting of the stop signal by the main and sub controllers are such that the sub controller 36 is less apt to execute the cutoff than the main controller 35.

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: A water heater with a hot water compartment, the volume of which is decreased when hot water is discharged. The remaining hot water is prevented from mixing with replacement cold water. The volume of the compartment is increased again when cold water has been heated and is pushed into the hot water compartment. The water heater is divided into a receiving compartment for water at ambient temperature and a compartment from which heated water is discharged for normal usage. The previously heated water is thereby prevented from mixing with replacement cold water. All compartments can be heated or the compartments can be heated individually. The water heater keeps the hot water temperature high between usage activities, and is suited for an intermittent energy source, e.g. solar power.

Abstract: A malfunction detection device for a hot water supplier has a tank temperature detection thermistor for detecting a hot water temperature of a hot water storage tank and is configured such that when the detected hot water temperature of the hot water storage tank is a reference temperature or higher, a relay provided at a tank printed circuit board stops power supply from a tank unit to a heat pump unit. A heat pump shutdown command is a standby power saving command for saving a standby power of the heat pump unit.

Abstract: The invention provides an apparatus for heating a liquid, which apparatus comprises: a mixing chamber; dispensing means for dispensing metered amounts of first and second chemical reactants into the mixing chamber to form a reaction mixture so that the chemical reactants undergo an exothermic chemical reaction to generate heat and one or more reaction products; an electronic control device linked to the dispensing means for controlling the dispensing of the metered amounts of first and second chemical reactants; one or more pumps for moving the chemical reactants and reaction mixture around the apparatus; a heat exchanger having an inlet and an outlet for the reaction mixture and an inlet and an outlet for the said liquid, so that when said liquid passes through the heat exchanger it is heated by heat transfer from the reaction mixture; one or more monitoring stations for monitoring one or more physical or chemical parameters of the reaction mixture; the monitoring stations being arranged to communicate wi

Abstract: A combined compact hot and ozonated cold water unit which comprises a framework that accommodates a hot water heater device, a ozone generator device and a combined temporary storage tank having both a hot water compartment and a separate cold water compartment. The hot water heater device is connected with the hot water compartment of the combined temporary storage tank for heating the water contained therein. The ozone generator device is connected with only the water compartment of the combined temporary storage tank for supplying ozone to the water contained therein.

Abstract: A gas burner including a burner body having a lower housing, an inlet conduit and a combustion surface element attached to the lower housing. A diffuser/reflector positioned within the body encourages even distribution and mixing of a combustible gas/air mixture. The diffuser/reflector is preferably of a sheet metal construction and includes a plurality of stamped openings with each of these openings having an overhanging guide plate. The combustion surface element includes a plurality of integrally formed rigidizing ribs and is made from a high temperature steel alloy wire cloth. The inlet conduit is secured directly or indirectly to an access door/bulkhead that is used to close off an access opening formed in a water heater wall through which the burner is installed. In one construction, an air scoop shrouds the inlet conduit and at least partially defines a flow path of primary air, substantially isolated from the combustion chamber.

Abstract: Disclosed is a hot-water system including a water tank with a water inlet and a water outlet for storing air-conditioning water; a pump motor, connected to the water outlet of the water tank through a connection pipe at one end thereof, circulating the air-conditioning water in the water tank by a pumping operation; an instantaneous water heater, connected to the other end of the pump motor by a connection pipe, instantaneously heating the air-conditioning water being circulated by the pumping operation of the pump motor; and an air-conditioning member, connected to both of the instantaneous water heater and the water tank to form an air-conditioning fluid path of a closed loop and guide the flow of the air-conditioning water; wherein the surface temperature of the air-conditioning member is increased by the heat of the air-conditioning water heated by the instantaneous water heater.

Abstract: A boiler unit (100) housed in an enclosure, the boiler unit (100) configured to receive a solid state combined heat and power generating device (130). The boiler unit (100) comprises a heating device (110) to produce heat; and a control unit (120) to independently control each of the heating device (110) and the solid state combined heat and power generating device (130). The boiler unit (100) is operable without the solid state combined heat and power generating device (130) being present.

Abstract: A water heater includes a combustor, a gas valve, a blower, a detector, and an operating device. The detector senses a speed of a motor of the blower.

Abstract: A thermostat is described for controlling air temperature in a building. The time associated with causing the controlled air temperature to reach a target temperature is estimated and displayed to a user. Input from a user indicating the target temperature can be received and the estimating and displaying can be carried out in real time. The thermostat can be wall-mounted or the user input can be received and estimated time can be displayed using a remote device, for example that communicates wirelessly with other components of the HVAC system.

Abstract: Hot water pipes, in areas with hard water, tend to fill with scale until they no longer pass enough water. De-scaling water pipes with acid is dangerous, expensive and damages the pipes. Ion exchange and reverse osmosis water softeners eliminate scale buildup in pipes, but are expensive. Embodiments of this invention provide a means of keeping an amount of the scale precipitate, created when water is heated, inside a housing by passing the hot water through a removal medium where the scale sticks to the surface. The removal medium can be placed inside the water heater or in a separate housing connected to the water heater; both configurations remove the precipitate from hot water; both save hot water pipes from scale accumulation.

Abstract: A hot water heater and method for controlling same. The hot water heater can be programmed to only heat water when the consumer anticipates that they will need it. The consumer can control the temperature of the water, the time at which the hot water will be needed, and can specify the speed vs. efficiency tradeoff regarding how the water is heated by selecting an operating mode, for example, thereby resulting in a more energy efficient and cost effective hot water heater.

Abstract: A water heating control and storage system, including an insulated tank for containing water to be heated. The storage system has a heat exchanger connected to the tank for using energy stored during off peak times as in water heated above normal storage temperature. An operation control device receives a demand response signal and enables water to be heated in a heat storing mode to heat water for usage. A method for controlling a water heating storage system includes providing an insulated tank for containing water to be heated; providing a heat exchanger coupled to the tank; and selectively operating in a heat storing mode in which water in the tank is heated to a higher than normal temperature and a heat exchange mode during which heat is extracted from the water stored in the tank by a heat exchanger for supplying stored energy to another energy consuming load in response to a demand response signal.

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 (31) 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 stored hot water over at least a determination time for prohibiting the use of stored hot water, 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: A fluid heater and a method for evaluating and displaying hot fluid supply time are disclosed. The system includes a fluid container, a controlling unit, a computational element, and a display means. The fluid container includes a cold fluid inlet means, a hot fluid outlet means, a first heating element, a second heating element, a first temperature sensor and a second temperature sensor. The controlling unit is adapted to selectively activate and deactivate one of the first heating element and the second heating element based on the inputs received from the said sensors. The computational element is adapted to compute the hot fluid supply time at a pre-determined set temperature based on at least one input received from said sensors, capacity of said fluid container, and flow rate of fluid to and from said fluid container. The display means is adapted to display the computed supply time.

Abstract: A gas-fired heating device having a burner, a pilot to provide a pilot flame, a thermopile thermally coupled to the pilot flame and configured to generate a power in response to the pilot flame, an electrically controlled gas valve to control the flow of gas to at least one of the pilot and the burner, and a controller electrically coupled to the thermopile and the gas valve. The controller receives and is powered by the power from the thermopile. The controller initiates closing of the gas valve after a monitored component of the power, such as a voltage, traverses a threshold.