A method of operating a cooktop appliance includes inputting a temperature measurement and a set temperature into a closed-loop control algorithm. When the output of the closed-loop control algorithm is less than a power level threshold, a first control valve to a gas burner of the cooktop appliance is closed.

A fuel nozzle assembly includes one or more tapered fuel nozzles. Each tapered fuel nozzle includes an acute trailing edge or tip at a top portion of the fuel nozzle. One or more fuel orifices are arranged proximate the acute trailing edge or tip. A tapered fuel nozzle having a toroidal airfoil structure includes a fuel channel to distribute a fuel to the fuel orifice(s). The fuel nozzle assembly may be provided as part of a burner system, including a perforated flame holder, and associated method, in which the fuel nozzle assembly is oriented to direct fuel form the fuel orifices toward the perforated flame holder.

A control valve may include a fluid inlet, a plurality of fluid outlets, and a plurality of magnets. One of the plurality of magnets controls fluid flow for each of one of the plurality of fluid outlets. One of the plurality of magnets controls fluid flow for the remaining of the plurality of magnets. When the magnet controlling fluid flow for the remaining of the plurality of magnets is energized, fluid flow is permitted to the remaining of the plurality of magnets. When the remaining of the plurality of magnets are energized, fluid flow is permitted to the respective plurality of fluid outlets.

A control device for gas appliances comprises at least one control module (20) having a supporting structure that can be associated to a gas tap (10) and defines a housing, contained within which is at least one first part of a circuit arrangement. The control module (20) comprises a command element operable by a user for activating at least one timing function and/or a function of ignition of a gas burner. The first part of the circuit arrangement comprises control elements, electrical-interconnection elements, and detection elements (45) configured for detecting actuation of the command element and supplying corresponding signals to the control elements. The circuit arrangement comprises further control and/or command elements (PSD, IS, F, LE, BC, ISC) and/or an auxiliary module (PSD).

An auxiliary hardware box is described that can be installed at or near the HVAC system. The auxiliary box includes a large number of wiring terminals, for example 16 or more, for connecting to a relatively large number of HVAC control wires. The auxiliary box can include a “train map” type graphic display that is visible to the installer and provides a graphical indication as to which relays or switches are currently open and which are currently closed. A small sleek visually pleasing thermostat is also described that can be connected either directly to an HVAC system or to the auxiliary box, and can automatically detect an purpose the connected wires according to which it is connected to.

A first reset switch is attached to a combustion controlling device. A second reset switch is installed at a remote place distant from the combustion controlling device. A first reset input from the first reset switch is received without any restriction to release the lockout. A reset input from the second reset switch is received with any restriction to release the lockout. Specifically, when the lockout releases are performed for a predetermined number of times or more upon receiving the reset input before a predetermined time elapses after the lockout has been released upon receiving the initial reset input, the release of the lockout upon receiving the reset input is prohibited until the predetermined time elapses.

A first reset switch is attached to a combustion controlling device. A second reset switch is installed at a remote place distant from the combustion controlling device. A first reset input from the first reset switch is received without any restriction to release the lockout. A reset input from the second reset switch is received with any restriction to release the lockout. Specifically, when the lockout releases are performed for a predetermined number of times or more upon receiving the reset input before a predetermined time elapses after the lockout has been released upon receiving the initial reset input, the release of the lockout upon receiving the reset input is prohibited until the predetermined time elapses.

Systems and methods for controlling mode transfers of a turbine combustor are provided. According to one embodiment, a system may include a controller to control a combustor, and a processor communicatively coupled to the controller. The processor may be configured to receive current operating conditions, target operating limits, and combustor transfer functions. The combustor transfer functions may be evaluated to estimate operating limits associated with one or more combustion modes under the current operating conditions. The estimated operating limits associated with the one or more combustor modes may be compared to the target operating limits, and, based on the comparison, at least one of the combustion modes may be selected. The combustor may then be selectively transferred to the selected combustion mode.

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.

A gas turbine engine includes a compressor section, a combustor fluidly connected to the compressor section via a primary flowpath, a turbine section fluidly connected to the combustor via the primary flowpath, and a plurality of fuel injectors disposed within the combustor. The plurality of fuel injectors including at least one start fuel injector. Also included is a controller having a memory and processor. The memory stores instructions configured to cause the at least one start fuel injector to pulse fuel through the start injector nozzle, thereby preventing stagnant fuel in the start injector nozzle from exceed a coking temperature threshold.