An indicator generating method for generating an indicator which is suitable for maintenance prediction of a water heating system is proposed. A power state indication device generates a high power consumption signal if a heating device of the water heating system is activated. The time duration of the activation is such an indicator, if no water flow is present. Furthermore, the time interval between subsequent activations is such an indicator. A predictive maintenance method processes these condition-based indicators and determines a remaining useful lifetime according to a predictive maintenance model. The predictive maintenance device outputs a maintenance signal indicating required maintenance, if the remaining useful lifetime drops below a predetermined threshold. The methods may be performed by water heating systems or beverage makers.

The flameless heater system includes an energy source comprising a diesel engine configured to create volumes of air, a hydraulic system to control engine loading for heat generation and for air moving, and a control system, operatively coupled with the energy source and the hydraulic system to control at least one of a speed of the diesel engine, a loading of the diesel engine, or a fan speed.

A control system is provided for controlling heating and/or cooling with a conditioning load such as fan coils and chilled beams. Based on user input and ambient conditions, the control system determines a desired temperature for the liquid entering the load and combines fresh supply liquid (e.g., from a chiller or boiler) with a portion of the liquid that has passed through the load, to achieve the target load input temperature for the liquid. A recirculation pump may be used to return a portion of the liquid exiting the load for mixing with the fresh supply liquid and a control valve may be used to adjust the ratio of fresh supply liquid and recirculated liquid to achieve the targeted temperature. The control systems can be compatible with a variety of liquid supply systems such as two- and four-pipe systems.

A method of controlling water heater pilot flame ignition includes receiving, by a controller of a water heater, a user input and controlling a pilot gas valve to start a gas flow to a pilot burner in response to the user input. The method further includes, in response to the user input, controlling, by the controller, an igniter to generate an ignition spark for lighting a pilot flame. The method also includes controlling, by the controller, the pilot gas valve to maintain the gas flow to the pilot burner if the pilot flame is lit.

An electrical power distribution control system configured to issue a demand response signal to cut power to a plurality of electrical power consuming loads within an electrical power distribution network to reduce a peak power demand within an electrical power grid during a peak power demand. Unlike conventional demand response systems, the controller in each consumer residence includes both a distributed control based on the ability to track individual 24 hour usage patterns and selectively delay the demand response signal on individual resistive heating loads based on usage patterns for the purpose of reducing a likelihood of consumers experiencing effects of the reduced peak power demand.

A fluid heating system including a burner unit is operated based on feedback control loops. The fluid heating system comprises a burner unit configured to heat a fluid, a sensor configured to sense a characteristic of the appliance, and a controller coupled to the burner unit and the sensor. The controller includes an electronic processor and a memory. The controller is configured to receive a first signal corresponding to the characteristic from the sensor, determine, based on the first signal, a first feedback loop control, control combustion of the burner unit based on the first feedback loop control, determine, based on the first feedback loop control, a second feedback loop control, and control combustion of the burner unit based on the second feedback loop control.

A fluid heating system including a burner unit is operated based on feedback control loops. The fluid heating system comprises a burner unit configured to heat a fluid, a sensor configured to sense a characteristic of the appliance, and a controller coupled to the burner unit and the sensor. The controller includes an electronic processor and a memory. The controller is configured to receive a first signal corresponding to the characteristic from the sensor, determine, based on the first signal, a first feedback loop control, control combustion of the burner unit based on the first feedback loop control, determine, based on the first feedback loop control, a second feedback loop control, and control combustion of the burner unit based on the second feedback loop control.

A heat pump assembly (100) arranged to be connected to a thermal energy circuit (300) comprising a hot conduit (302) configured to allow thermal fluid of a first temperature to flow therethrough, and a cold conduit (304) configured to allow thermal fluid of a second temperature to flow therethrough, the second temperature is lower than the first temperature, and a cooling machine assembly (200) arranged to be connected to a thermal energy circuit (300) comprising a hot conduit (302) configured to allow thermal fluid of a first temperature to flow therethrough, and a cold conduit (304) configured to allow thermal fluid of a second temperature to flow therethrough.

A combination boiler provides heated water to a boiler loop and domestic hot water (DHW) to a domestic water loop. The combination boiler includes a primary heat exchanger (PHE) connected to the boiler loop and a burner to provide heat to the primary heat exchanger. A secondary heat exchanger (SHE) transfers heat energy from the boiler loop to the domestic water loop. A controller monitors a PHE inlet temperature and a DHW output temperature, obtains a pre-heat initialization temperature threshold and a pre-heat cancellation temperature threshold, and detects a low temperature condition. A pre-heat operation is initiated responsive to the low temperature condition by circulating heated water from the PHE to the SHE. The burner is selectively fired at least in part according to an outlet temperature of the PHE.

A method for controlling a gas furnace that performs a heating operation by receiving a first heating signal; calculating a certain heating capacity smaller than a maximum heating capacity of the gas furnace, according to the first heating signal; and operating a heating of the gas furnace with the calculated certain heating capacity. The calculating of the certain heating capacity includes calculating the certain heating capacity according to a difference between an intake air temperature sucked into the gas furnace and a reference temperature.