A gas burner includes a burner body that defines a plurality of naturally aspirated flame ports and a plurality of forced induction flame ports. A first gas orifice is mounted to an injet body such that the first gas orifice is oriented for directing a flow of gaseous fuel towards the plurality of naturally aspirated flame ports. A second gas orifice and the injet body form an eductor mixer within a mixing chamber of the injet body. A mixed outlet nozzle is mounted to the injet body at the mixing chamber such that the mixed outlet nozzle is oriented for directing a mixed flow of air and gaseous fuel from the mixing chamber towards the plurality of forced induction flame ports.

A gas burner includes a burner body that defines a plurality of forced induction flame ports. An air outlet orifice is mounted to an injet body at an outlet of an air passage such that the air outlet orifice is oriented for directing a flow of air towards the plurality of forced induction flame ports. A gas outlet orifice is mounted to the injet body at an outlet of a gas passage such that the gas outlet orifice is oriented for directing a flow of gaseous fuel towards the plurality of forced induction flame ports. A pneumatically actuated gas valve is positioned within the injet body. The pneumatically actuated gas valve is configured to adjust from a closed configuration to an open configuration in response to the flow of air through the air passage.

A gas burner includes a burner body that defines a plurality of forced induction flame ports. An air outlet orifice is mounted to an injet body at an outlet of an air passage such that the air outlet orifice is oriented for directing a flow of air towards the plurality of forced induction flame ports. A gas outlet orifice is mounted to the injet body at an outlet of a gas passage such that the gas outlet orifice is oriented for directing a flow of gaseous fuel towards the plurality of forced induction flame ports. A pneumatically actuated gas valve is positioned within the injet body. The pneumatically actuated gas valve is configured to adjust from a closed configuration to an open configuration in response to the flow of air through the air passage.

One aspect of this disclosure provides a heat exchanger that comprises a first panel half coupled to a corresponding second panel half that form a passageway having at least a first chamber adjacent an inlet end of the passageway and a second chamber and overlapping interference patterns formed in each of the first and second panel halves that extend along at least a portion of the length of the passageway and located between at least the first and second chambers.

One aspect of this disclosure provides a heat exchanger that comprises a first panel half coupled to a corresponding second panel half that form a passageway having at least a first chamber adjacent an inlet end of the passageway and a second chamber and overlapping interference patterns formed in each of the first and second panel halves that extend along at least a portion of the length of the passageway and located between at least the first and second chambers.

A premixing apparatus has: a fan; an air tube; and a gas tube inside the air tube; provided that a direction toward an air flow upstream side inside the air tube is defined as an X+ direction, an air adjusting valve facing an air inlet port positioned at an end, in the X+ direction, of the air tube; a gas adjusting valve facing a gas outlet port positioned at one end of the gas tube; and a common actuator driving the air adjusting valve and the gas adjusting valve. At an end, in the X direction, of the gas tube, is disposed a valve seat having formed therein the gas outlet port, and a gas adjusting valve inside the gas tube. A valve stem penetrates through an end wall, in the X+ direction, of the gas tube. The gas adjusting valve is driven by the actuator through the valve stem.

A premixing apparatus has: a fan; an air tube; and a gas tube inside the air tube; provided that a direction toward an air flow upstream side inside the air tube is defined as an X+ direction, an air adjusting valve facing an air inlet port positioned at an end, in the X+ direction, of the air tube; a gas adjusting valve facing a gas outlet port positioned at one end of the gas tube; and a common actuator driving the air adjusting valve and the gas adjusting valve. At an end, in the X direction, of the gas tube, is disposed a valve seat having formed therein the gas outlet port, and a gas adjusting valve inside the gas tube. A valve stem penetrates through an end wall, in the X+ direction, of the gas tube. The gas adjusting valve is driven by the actuator through the valve stem.

A premixing device includes a first and a second venturi in which air flows by rotation of a centrifugal fan, first and second communication openings disposed in the venturis, respectively, for allowing fuel gas supplied from a gas supply passage to flow out, a flap valve capable of opening and closing the second venturi on a side downstream of the second communication opening, and an equalizing valve disposed in the gas supply passage on a side upstream of the first and the second communication openings. The gas supply passage, which connects between an outlet of the equalizing valve and the first and the second communication openings, diverges from the outlet of the equalizing valve to independently form a first gas passage and a first straight path, and a second gas passage and a second straight path for the venturis, respectively.

A heating device includes a combustion chamber, a housing in fluid communication with the combustion chamber, a burner disposed in the housing, a blower assembly connected to the housing for directing air into the interior of the housing, a valve assembly connected to the housing for controlling a flow of fuel into the burner, an optical color sensor for sensing a color profile of a surface of the burner, and a control unit configured to control the valve assembly in dependence upon the color profile of the surface of the burner.

A heating device includes a combustion chamber, a housing in fluid communication with the combustion chamber, a burner disposed in the housing, a blower assembly connected to the housing for directing air into the interior of the housing, a valve assembly connected to the housing for controlling a flow of fuel into the burner, an optical color sensor for sensing a color profile of a surface of the burner, and a control unit configured to control the valve assembly in dependence upon the color profile of the surface of the burner.