A fuel-fired heating appliance comprises a fuel source, an air source, a chamber in which fuel and air mix, a burner downstream from the mixing chamber, an igniter proximate the burner, a heat exchanger, a blower and a flue pipe. An ambient air inlet may be defined by at least one of the outlet end of the blower and the flue pipe extending between the interior of the flue pipe and an area ambient to the flue pipe. A flow rate of combustion gas may be controlled to a level below a steady-state flow rate during appliance warm-up.

A heater includes short and tall cabinet units that are connected together, and an ignition unit. The short cabinet unit has a recess facing upwardly, and a first receiving space spatially communicated with the recess. The tall cabinet unit has a second receiving space spatially communicated with the first receiving space. The ignition unit includes an ignition seat disposed in the recess, an igniter mounted to the ignition seat, and a gas pipe group connected to the igniter and extending from the first receiving space into the second receiving space. A height of the short cabinet unit ranges from 45 centimeters to 60 centimeters; a height of the tall cabinet unit ranges from 65 centimeters to 70 centimeters.

A fuel-fired heating appliance comprises a fuel source, an air source, a chamber in which fuel and air mix, a burner downstream from the mixing chamber, an igniter proximate the burner, a heat exchanger, a blower and a flue pipe. An ambient air inlet may be defined by at least one of the outlet end of the blower and the flue pipe extending between the interior of the flue pipe and an area ambient to the flue pipe. A flow rate of combustion gas may be controlled to a level below a steady-state flow rate during appliance warm-up.

Disclosed is an air heating apparatus including a burner configured to cause a combustion reaction, a heat exchanging device configured to receive heat from combustion gas generated by the combustion reaction and heat water, a heating heat exchanger configured to receive the water heated by the heat exchanging device and exchange heat with the air for heating, a main passage, in which the heat exchanging device and the heating heat exchanger are disposed, and configured such that the water flows therethrough while circulating, and a fan configured to blow the air to the heating heat exchanger.

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 heating device includes a base member and a gas burner mounted in or on the base member. An upper housing located above the base member and a tabletop mounted above the upper housing. A hollow heat shield having a proximal end located on or near the base member, and a distal end located within the upper housing, and a support member extending between the base member and the upper housing or tabletop. The distal end of the heat shield extends beyond a proximal end of the upper housing, defining a region of vertical overlap between the heat shield and the upper housing.

A high turndown furnace for an air handling system. In one example, the furnace includes a plurality of tubes divisible by four with a first modulating valve supplying gas to ¼ of the tubes and a second modulating valve supplying gas to ¾ of the tubes. In one aspect, the furnace is capable of providing a 16:1 turndown. In one aspect, the furnace is capable of providing seamless turndown operation throughout the entire firing range.

A radiant heating assembly including a burner for heating a heat exchanger and a reflector generally disposed about the heat exchanger. The reflector comprising a base defining a first air chamber. The reflector may also comprise one or more wings removably coupled to the base. The wings may be configured to define a second air chamber. The radiant heating assembly may also comprise an air circulation pump configured to draw air through the air chamber of the base and/or wing and provide the air to the burner to improve the efficiency of the combustion process.

A linear fireplace system, assemblies, modular units, and related methods that can be installed in a modular fashion at a selected installation location so as to avoid drawbacks experienced in the prior art. The system can include modular linear units, corner units, and/or end units interconnectable to form a modular linear fireplace assembly. The system can include an alignment track system with a track member that receives alignment rails on the bottom of the modular units to axially align the interconnected units. The system can include a combustion air flow passage within the fireplace that maintains a relatively low exterior temperature of the assembly and that allows combustible and non-combustible building materials to be installed against or immediately adjacent to the top and base portions of the modular units of the assembly.

The disclosed technology includes systems and methods for detecting an at least partially obstructed air filter in a furnace. The disclosed technology can include a system and method that can receive temperature data from a flame sensor configured to detect a temperature of a flame in a burner, determine that an air filter associated with the burner is at least partially obstructed by determining that the temperature data indicates the flame temperature is greater than or equal to a threshold temperature, and output an alarm signal indicating that the air filter is at least partially obstructed.