A motor controller for a burner system includes an inverter that supplies current to a motor that rotates a draft inducer fan. A processor is coupled to the inverter and receives a signal from a system controller, and in response instructs the inverter to supply a first current, during a first period, to the motor to rotate the fan to produce a first mass flow through the burner system, the first mass flow having a first mass flow rate greater than a threshold to actuate a vacuum switch. The processor then instructs the inverter to supply a second current, during a second period starting at an expiration of the first period, to the motor to rotate the fan to produce a second mass flow through the burner system, the second mass flow having a target mass flow rate for normal operation of the burner.

A furnace system includes a heat exchanger and a burner assembly including a burner enclosure fluidly coupled to the heat exchanger. The burner assembly is configured to receive a fluid, ignite the fluid to produce combustion byproducts, and direct the combustion byproducts to the heat exchanger. The furnace system also includes a pressure sensor configured to detect a pressure within the burner enclosure. The furnace system is configured to operate based on the pressure detected by the pressure sensor.

A gas burner assembly for a cooktop appliance includes a normally aspirated primary burner and a concentrically-positioned forced air boost burner. A dual-outlet solenoid valve receives fuel from a fuel source and selectively directs the fuel to a first solenoid outlet in fluid communication with the primary burner and a second solenoid outlet in fluid communication with the boost burner. The solenoid valve is positionable in a first position where the first solenoid outlet is substantially open and the second solenoid outlet is substantially closed and a second position where the first solenoid outlet is partially open and the second solenoid outlet is substantially open.

A gas burner assembly for a cooktop appliance includes a normally aspirated primary burner and a concentrically-positioned forced air boost burner. A dual-outlet solenoid valve receives fuel from a fuel source and selectively directs the fuel to a first solenoid outlet in fluid communication with the primary burner and a second solenoid outlet in fluid communication with the boost burner. The solenoid valve is positionable in a first position where the first solenoid outlet is substantially open and the second solenoid outlet is substantially closed and a second position where the first solenoid outlet is partially open and the second solenoid outlet is substantially open.

A furnace system includes a heat exchanger and a burner assembly including a burner enclosure fluidly coupled to the heat exchanger. The burner assembly is configured to receive a fluid, ignite the fluid to produce combustion byproducts, and direct the combustion byproducts to the heat exchanger. The furnace system also includes a pressure sensor configured to detect a pressure within the burner enclosure. The furnace system is configured to operate based on the pressure detected by the pressure sensor.

A premixing apparatus that mixes a fuel gas with air and supplies an air-fuel mixture in a burner through a fan includes a control device that is configured to carry out a third control that: calculates and memorizes a lower limit of a rotational speed of a fan, at which an increase of an opening degree of a variable throttle valve becomes necessary, as a first threshold; and when the rotational speed of the fan increases to the first threshold or faster next time, immediately changes the opening degree of the variable throttle valve to an increased opening degree, which is larger than a predetermined standard opening degree and is obtained by multiplying a deviation of the rotational speed of the fan from the first threshold by a predetermined coefficient.