A method for evaluating a quasi-stationary pressure difference detectable by a sensor at a gas boiler. The gas boiler has a mixing device (4), a fan (5), a main flow regulator (3), .a control valve (2) and a safety valve (1). The sensor detects a differential pressure between a pressure (p2) at a measuring point upstream of the main flow regulator (3) and downstream of the control valve (2) and a reference pressure (p0, p1) at a reference measuring point. The sensor transmits a signal to an electronic evaluation system. The electronic evaluation system compares the differential pressure during a pre-purge phase, wherein the safety valve (1) is closed, with the differential pressure after the pre-purge phase and detects an error by the comparison.

A gas appliance comprises a combustion device, an ignitor, a gas valve, a blower, a detecting device, and a control device. A control method thereof comprises: the control device is operated in a detection mode in which the control device controls the ignitor to ignite and controls the gas valve as well as the blower to provide a fixed gas flow and a fixed air flow to the combustion device. After igniting the flames, the control device determines burning states detected by the detecting device; if matching a first state, the control device controls the gas valve and the blower in correspondence to a first control data of the first natural gas; if matching the second state, the control device controls the gas valve and the blower in correspondence to a second control data of the second natural gas. In this way, the gas appliance is suitable for burning natural gas generating various heating values.

A method of operating a cooktop appliance in a precision mode includes determining a starting temperature and a set of parameters of a closed-loop algorithm for operation of a heating element corresponding to the starting temperature. The method also includes inputting a user-determined set temperature and a current temperature measurement into the closed-loop control algorithm and determining an output of the closed-loop control algorithm using the set of parameters corresponding to the starting temperature. Operation of the heating element is adjusted according to the output of the closed-loop control algorithm.

A method of operating a cooktop appliance includes receiving a first user-determined set temperature, determining a first set of parameters for a closed-loop control based on the first user-defined set temperature and operating a heating element of the cooktop appliance according to a first output of closed-loop control using the first set of parameters. The method also includes receiving a second user-determined set temperature after the first user-defined set temperature. The second user-defined set temperature differs from the first user-defined set temperature. The method further includes determining a second set of parameters of the closed-loop control based on the second user-determined set temperature, and operating the heating element according to a second output of the closed-loop control using the second set of parameters based on the second user-determined set temperature.

A fuel valve for regulating a flow of fuel to a combustion appliance includes a control module configured to determine fuel consumption based on a measure related to fuel flow through the fuel valve. The measure related to fuel flow through the valve may be determined using a known relationship between firing rate and the flow rate of fuel through the valve. Measurement accuracy may be enhanced by correcting for the excess air ration (also referred to as lamda).

A gas grill is disclosed having a gas control valve with a push to sear feature. The gas control valve has a housing with a valve core rotatably disposed within the housing. A sear valve is disposed within the valve core. A user rotates the valve core within the housing to selectively align a gas inlet port with an inlet passage and to align a sear gas port and a sear gas flow passage. The sear valve has a sear valve element which is selectively movable relative to the valve core to selectively pass a sear gas through a sear gas port and a sear flow passage to the forward end of the valve housing, and then to the grill. A bias member, preferably a coil spring, is mounted between the sear valve element and the valve core for urging the sear valve element to a closed position.

A volatiles consuming eductor system for coated scrap metal furnaces with separate delacquering and melt chambers. Motive gas is forced through an inlet into a mixing chamber in a direction opposite a suction port, creating a Venturi that draws gases from the delaquering chamber through the mixing chamber. The motive gas and the drawn gases mix and are forced through a discharge port, ignited, and injected into the melt chamber to help heat the melt chamber. A computer monitors process conditions and controls a regulator that adjusts the motive gas flow in response to those conditions.

A cooking appliance and method may generate one or more audible and/or visual indications to a user of various gas burner states during the operation of a gas burner, including, for example, states that are associated with different types of ignition operations, such as initial ignition operations, programmed re-ignition operations and/or flame loss re-ignition operations and/or states that are associated with ignition operations, normal operating conditions, and/or failure conditions.

The invention relates to a gas valve unit, comprising a valve body surrounding an inner chamber in a sealing manner; an inlet part; at least one gas outlet in connection with the inner chamber to conduct gas via an outlet channel; a stationary disc member dividing the inner chamber; a rotating control disc member which is superimposed on a corresponding rear wall of the stationary disc member from an inner wall and mounted on a lower part which extends into the inner chamber of a control rod extending out from the body; also an elongated cavity formed in the inner wall of the control disc member and aligned to direct the gas flow to the through hole in an operational position.

A premixing apparatus in which a downstream end of a gas supply passage is connected to a gas suction section disposed in an air supply passage on an upstream side of a fan, is provided with: a butterfly valve driven by a stepping motor, for changing over, between high and low, a ventilation resistance in that section of the air supply passage which is on an upstream side of the gas suction section; a changeover valve for changing over, between high and low, a ventilation resistance in that section of the gas supply passage which is on an upstream side of a flow control valve; and an interlocking mechanism which opens or closes the changeover valve in interlocking with the rotation of the butterfly valve and which maintains the changeover valve in a closed state until the butterfly valve has rotated from the closed posture toward the opening side by a predetermined angle. Flame failure and poor combustion are prevented at the time of changing over the butterfly valve and the changeover valve from closed posture to opened posture.

When the butterfly valve is rotated from the closed posture into the opened posture, a driving frequency of the stepping motor is made higher, until the butterfly valve has rotated from the closed posture toward the opening side by a predetermined set angle, than the driving frequency during the subsequent operation of the butterfly valve.