Provided is a gas furnace including a primary heat exchanger and a secondary heat exchanger through which a combustion gas produced by the combustion of a fuel gas flows. The gas furnace includes: a coupling box serving as an intermediary to connect the primary heat exchanger and the secondary heat exchanger; a collect box connected to the secondary heat exchanger, for letting in the combustion gas passed through the secondary heat exchanger; an inducer connected to the collect box, for inducing a flow of the combustion gas; and a bypass pipe connected to one side of the coupling box and including a bypass pipe for guiding the combustion gas passed through the primary heat exchanger to a hot water supply tank for supplying hot water to an indoor space.

The disclosed technology includes a system and method of preventing short cycling in a water heater. The system can include a burner, a temperature sensor, and a controller. The controller can be configured to perform several steps to determine whether to turn on a burner and whether to increment a temperature offset value based on the amount of time that has elapsed since the last time the burner was on.

A water heater system includes a gas burner configured to selectively produce flue gases, and a heat exchanger for heating water in the water heater system. The water heater system is operable in a heating mode, and a standby mode. An exhaust assembly is in communication with the heat exchanger, and includes a condensate collector configured to receive the flue gases and condensate. A first temperature sensor is positioned to sense a temperature of the condensate within the condensate collector. The first temperature sensor is configured to detect a rate of temperature change of the condensate. A controller is configured to determine a leakage when the rate of temperature change adjusts from a first state to a second state when the water heater system is in the standby mode after the water heater system was in the heating mode.

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.

A gas manifold allows each distribution chamber to be fed with fuel gas at an appropriate flow rate irrespective of an increase in the number of distribution chambers included in the gas manifold. A gas manifold distributes fuel gas flowing in through an inlet to a plurality of distribution chambers through a main channel. The main channel includes a flow guide that guides the fuel gas toward a maximum distribution chamber and reduces the fuel gas flowing into other distribution chambers. This allows fuel gas at a sufficient flow rate to be fed more easily to the maximum distribution chamber than to the other distribution chambers for a larger number of distribution chambers included in the gas manifold, allowing the plurality of distribution chambers to be fed with fuel gas at appropriate flow rates.

The present invention relates to a boiler which determines a clogging degree of an exhaust flue through which combustion gas is discharged and adjusts gas supply amount to maintain its combustibility, and a combustion control method thereof, the method of the present invention including a) setting a target heat value for achieving a target temperature, b) applying a first database on the basis of the target heat value, c) measuring a rotational speed of an air blower and a pneumatic pressure of air introduced by rotation of the air blow, d) applying a second database on the basis of a rotational speed difference, a pneumatic pressure difference, and the target heat value to calculate an estimated flue clogging value according to the target heat value, and a) applying a third database according to the estimated flue clogging value to calculate an opening amount of a gas valve and control gas supply amount.

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 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 heating ventilation and air conditioning (HVAC) control system. The HVAC control system includes a sensor that detects a refrigerant released from an HVAC system and emits a signal indicative of the detection. The HVAC control system also includes a switch that blocks a flow of electricity to an enclosed space and a controller that receives the signal from the sensor and activates the switch to block the flow of electricity in response to detection of the refrigerant.