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.

Disclosed are a method for controlling a heating water heater, a heating water heater, and a computer-readable storage medium. The method includes: controlling the heating outlet to be closed and the heat supply outlet to be opened after receiving a bath water signal; obtaining a water temperature of a bath outlet; obtaining a duration that the water temperature at the bath outlet is within a preset water temperature range; controlling an opening degree of the heat supply outlet to decrease and an opening degree of the heating outlet to increase when the duration is greater than or equal to a first preset duration, and a heat load of the heating water heater is less than a rated load; and controlling the heat load of the heating water heater to increase, and maintaining the water temperature at the bath outlet within the preset water temperature range.

A water heater can include a heat source and a heat exchanger that transfers heat to the water. A header attached to the heat exchanger provides an inlet and an outlet for water to flow into and out of the heat exchanger. The header can also include an anode assembly that releasably attaches to the header. The anode assembly can be located at a bottom of the header so that an anode in the anode assembly remains in contact with the water when water is flowing through the heat exchanger.

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.

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.

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.

A flame sensor for a furnace of a heating, ventilation, and air conditioning (HVAC) system includes a sensor body and an electrically conductive member of the sensor body. The electrically conductive member is configured to be disposed within a flame region of a burner of the furnace and configured to receive electrical current from a controller of the furnace. The flame sensor also includes an anti-oxidation coating disposed on an outer surface of the electrically conductive member and configured to transmit the electrical current from the electrically conductive member. The anti-oxidation coating is configured to contact a flame produced by the burner and expose the electrical current to the flame.

A method of controlling a gas furnace system includes determining a first pressure in a conduit coupled to a draft inducer from signals output by a pressure transducer positioned to sense a pressure within the conduit with a motor of the draft inducer in a stopped condition. A first status of the pressure transducer is determined based at least in part on the first pressure. The motor of the draft inducer is controlled to increase a speed of the motor from the stopped condition in response to a call for heat when the first status does not indicate that the pressure transducer is unreliable, and the motor is maintained in a stopped condition when the first status indicates that the pressure transducer is unreliable.

The present invention provides a method of operating a gas heater for water including the steps of: restricting a water flow to the gas heater; determining a first rate of a first gas heating for the restricted water flow; adjusting the gas heating to the restricted water flow; repeating the previous steps until a heated water has a temperature above a temperature threshold; removing the restriction to the water flow to increase the water flow; and determining a second rate of a second gas heating for the increased water flow. The present invention also provides a gas water heater which utilises such a method.