A gas valve assembly with integrated pressure regulator is provided. The gas valve assembly includes a pressure regulator and a gas valve module. The pressure regulator and gas valve modules each include cast housing bodies. The cast housing bodies have cast in mounting holes and assembly features that allow for the assembly of the gas valve assembly without secondary machining operations.

A controller for a gas furnace, a computer-usable medium for implementing a method and a gas furnace are disclosed herein. In one embodiment, the controller includes: (1) an interface configured to receive a heating call and (2) a processor configured to enable an inducer of the gas furnace at a low speed based on the heating call and ignite the gas furnace at a high fire operation when determining a low fire pressure switch of the gas furnace is open.

Method for operating a gas burner appliance (10), the gas burner appliance com-prising: a combustion chamber (11) in which a defined gas/air mixture is combusted after combustion has been started; a mixing device (25) to provide said gas/air mixture by mixing an air flow provided by an air duct (15) with a gas flow provided by a gas duct (16); a fan (14) to provide the air flow or the flow of the gas/air mixture; a gas safety valve unit (19) assigned to the gas duct to open or close the gas duct; a gas flow modulator (18) or a gas flow regulator (28) assigned to the gas duct to keep a mixing ratio of the defined gas/air mixture constant over the modulation range of the gas burner appliance; an absolute pressure sensor (21) positioned between the gas safety valve unit and the mixing device, wherein the gas burner appliance is operated to determine the air flow resistance of the same by executing the following steps before combustion becomes started: Measuring a first absolute pressure by the absolute pressure sensor (21) when the gas safety valve unit (19) is closed and when the fan (14) is stopped. Measuring a second absolute pressure by the absolute pressure sensor (21) when the gas safety valve unit (19) is closed and when the fan (14) is running. Determining a pressure difference between the first absolute pressure and the second absolute pressure. Determining on basis of the pressure difference the air flow resistance of the gas burner appliance.

A locally powered intermittent pilot combustion controller may include an igniter, a thermal electric and/or photoelectric device that produces an electrical signal having power when exposed to a flame, and a local power source for providing power when the thermal electric and/or photoelectric device is not exposed to a flame. In some cases, the intermittent pilot combustion controller may include a memory for storing information about an ignition sequence for igniting a pilot flame, and a controller coupled to the memory. The controller may be configured to initiate the ignition sequence of the pilot flame using information stored in the memory, determine whether the ignition was successful by monitoring the electrical signal produced by the thermal electric and/or photoelectric device, and adjust the information stored in the memory based on whether the ignition sequence completed successfully.

Exemplary embodiments are disclosed of controls including circuit assemblies configured for determining igniter, inducer relay, and igniter relay faults. In exemplary embodiments, a control for a system includes an input configured to receive a control signal, an inducer relay, an igniter relay, and a circuit assembly. The circuit assembly is configured to be coupled to the inducer relay, the igniter relay, and an igniter of the system. The circuit assembly comprises a plurality of diodes and is configured to enable detection of and distinguishing between a failure of the igniter, a failure of the inducer relay, and a failure of the igniter relay as determined by a waveform of the control signal at the input of the control for a given one of a plurality of operational states of the control.

A controller memorizes an accumulated combustion time by accumulating combustion time of a burner, and is set in a first lower-limit and a second lower-limit higher than the first lower-limit as a lower-limit lower than an initial value of an excess air ratio when reducing an excess air limit of a mixture gas of combustion air and a fuel gas, and the former is the lower-limit in case the accumulated combustion time is under a predetermined set time and the latter is the one in case the accumulated combustion time is the predetermined set time and over.

Exemplary embodiments are provided of igniter failure detection assemblies for furnaces. In an exemplary embodiment, an igniter failure detection assembly includes a hot surface igniter, an igniter relay coupled to the hot surface igniter, a resistor coupled in parallel with the hot surface igniter and defining a node between the igniter relay, the resistor and hot surface igniter, and a controller configured to detect a voltage at the node and determine whether a fault condition of the hot surface igniter exists based on the detected voltage at the node. A detected node voltage corresponding to a normal operation resistance value of the hot surface igniter is indicative of a normal operating hot surface igniter, and a detected node voltage corresponding to a resistance value of the resistor is indicative of a fault condition of the hot surface igniter. Example methods of detecting an igniter fault condition are also disclosed.

Method for operating a gas burner appliance (10). the gas burner appliance (10) comprising: a combustion chamber (11) in which a defined gas/air mixture is combusted. a mixing device (23) to provide said gas/air mixture. a gas safety valve unit (19) assigned to the gas duct (16) to open or close the gas duct (16) having a first gas safety valve (19a) and a second gas safety valve (19b) positioned downstream of the first gas safety valve (19a). a gas flow modulator (18) assigned to the gas duct (16), an electrical or electronic absolute pressure sensor (21) positioned downstream of the first gas safety valve (19a). wherein the gas burner appliance (10) goes into lockout state if a defined number of burner-start-ups of the gas burner appliance (10) failed. namely did not result into a combustion, and wherein the gas burner appliance (10) is operated by executing the following steps to provide an electrical or electronic pressure-switch functionality: Before each burner-start-up of the gas burner appliance (10) measuring a first absolute pressure by the absolute pressure sensor (21) when the first gas safety valve (19a) is closed. During each burner-start-up of the gas burner appliance (10) measuring a second absolute pressure by the absolute pressure sensor (21) when the first gas safety valve (19a) is opened, determining a pressure difference between the first and second absolute pressure, and comparing the pressure difference with a threshold. A lockout of gas burner appliance (10) is allowed or prevented on basis of the comparison of the pressure difference with the threshold.

A pseudo flame detecting portion detects a presence of a pseudo flame due to disturbance light when a sensor output of a flame sensor is equal to or greater than a pseudo flame threshold value and detects an absence of pseudo flame when the sensor output is equal to or less than another pseudo flame threshold value. The combustion controlling portion monitors the pseudo flame detection result from the pseudo flame detecting portion before an ignition attempt in the combustion equipment and, when the pseudo flame detection result continuously indicates presence of pseudo flame for a first monitoring time, cancels the ignition attempt in the combustion equipment.

A method for detecting a flame is provided. The method includes the step of providing alternating current to a flame rectification probe to produce a first voltage as an input for a sense circuit, wherein the flame rectification probe is placed in proximity to the flame. The method further includes the step of conditioning the first voltage using the sense circuit to produce a second voltage. Additionally, the method includes the steps of outputting the second voltage to a microcontroller, and determining with the microcontroller whether the flame is present based on a magnitude of the second voltage.