A water heater includes a plurality of stages of burners, a water supply pipe, a hot water outlet pipe, a heat exchanger, a passing water quantity control unit, a temperature detection unit, and an operation control unit. The operation control unit, upon confirmation that a predetermined start condition of a passing water restriction is satisfied at a start of a hot water supply, performs the output hot water temperature control by calculating a target flow rate that causes no switching or a minimum count of switching of the combustion stages of the burners and configuring the passing water quantity control unit to have the target flow rate. The operation control unit, upon confirmation that a predetermined release condition of the passing water restriction is satisfied, executes the passing water control in which the passing water quantity is returned to the predetermined water quantity by gradually releasing the passing water restriction.

A burner system includes a plurality of burners, each having a nozzle positioned to emit a stream of fuel into a combustion volume, and a perforated flame holder, including a plurality of apertures extending between first and second faces thereof, and positioned to receive a stream of fuel from the respective nozzle. In operation, the flame holders are configured to hold a flame substantially within the plurality of apertures.

The invention relates to a heating device, in particular for mobile use, comprising a combustion chamber for reacting fuel with combustion air in order to release heat, a heat exchanger for transferring at least part of the released heat to a heating medium to be heated, a fuel conveying device for supplying fuel to the combustion chamber, a combustion air fan for supplying combustion air to the combustion chamber, a heating medium fan for supplying the heating medium to the heat exchanger, a common drive for the combustion air fan and the heating medium fan, at least one sensor for monitoring the mass flow of the heating medium, and a controller, which controls the fuel conveying device and the common drive. The controller is designed to change the ratio of the amount of the heating medium and the amount of the fuel supplied to the combustion chamber according to the mass flow of the heating medium.

A method of operating a heat releasing reactor producing product gas. The method includes steps of (a) monitoring a current load of the reactor, (b) finding such a numerical value for a current computational maximum momentary load for which at least one product gas factor computed using currently monitored process data with a numerical model of the reactor fulfills an acceptance condition, and selecting the numerical value as the current computational maximum momentary load, (c) indicating the current computational maximum momentary load to the operator and/or, if the current load is (c1) less than the current computational maximum momentary load, (c1i) indicating the operator that the load may be increased, and/or (c1ii) automatically increasing the load, and/or (c2) greater than the current computational maximum momentary load, (c2i) indicating the operator that the load exceeds the current computational maximum boiler momentary load, and/or (c2ii) automatically reducing the boiler load.

A combination boiler provides heated water to a boiler loop and heated domestic hot water (DHW) to a DHW loop. A primary heat exchanger is connected to the boiler loop. A burner provides heat to the primary heat exchanger and an input fan supplies a fuel and air mixture to the burner. A secondary heat exchanger transfers heat energy from the boiler loop to a domestic water loop. A controller determines a boiler loop flow rate. The controller measures an input temperature of the boiler loop, an output temperature of the boiler loop, and a DHW output temperature of the domestic water loop. The controller determines a DHW input temperature and estimates a DHW flow rate. The input fan speed is initiated or operated according to a required heat output of the burner corresponding to the DHW flow rate.

A gas appliance comprises a combustion device, an ignitor, a gas valve, a blower, a detecting device, and a control device. A control method thereof comprises: the control device is operated in a detection mode in which the control device controls the ignitor to ignite and controls the gas valve as well as the blower to provide a fixed gas flow and a fixed air flow to the combustion device. After igniting the flames, the control device determines burning states detected by the detecting device; if matching a first state, the control device controls the gas valve and the blower in correspondence to a first control data of the first natural gas; if matching the second state, the control device controls the gas valve and the blower in correspondence to a second control data of the second natural gas. In this way, the gas appliance is suitable for burning natural gas generating various heating values.

A safety system for use with a thermoelectric generator is described. The safety system includes a safety switch operatively connected to the thermoelectric generator output. The safety switch has a first state in which the thermoelectric generator can provide a first voltage to a load, and a second state in which the thermoelectric generator cannot output the first voltage to the load and in which the thermoelectric generator can output a second voltage to the load. The second voltage is a non-zero voltage having a magnitude less than the first voltage.

The present invention relates to a method for detecting a blockage in an exhaust flue of a gas boiler, comprising: (A) a step for conducting an ignition process according to a user set temperature requested from the outside and performing temperature control to reach the user set temperature; (B) a step for determining whether the current fan RPM of a driven blower exceeds a reference fan RPM; (C) a step for calculating a difference between temperature values of supplied heating water and collected heating water that are detected by temperature sensors when heating water is supplied and determining whether the calculated value is less than a preset reference temperature value when it is determined that the current fan RPM exceeds the reference fan RPM; (D) a step for determining whether the elapsed time elapses a preset setting time based on the determination time point of the step (C) when it is determined that the calculated value is less than the reference temperature value; and (E) a step for displaying, on the outside, a notification that the blockage in the exhaust flue has been identified when it is determined that the elapsed time has elapsed the setting time based on the determination time point of the step (C).

A water heater system including a boiler having a heat exchanger and an indirect water heater having a heat exchanger, and a controller configured to activate a pump such that the water flows between the boiler heat exchanger and the indirect water heater heat exchanger, and to control a heat source to provide heat to the boiler at a firing rate. The water heater system measuring temperatures of the water at the boiler water inlet and at the boiler water outlet, calculating an amount of heat transfer from the boiler heat exchanger to the indirect water heater exchanger based on the measured temperatures, and adjusting the firing rate based on the calculated amount of heat transfer to determine a heat transfer capacity of the indirect water heater exchanger.