Lennox LD24-75A, Gas-Fired Duct Furnace, Aluminized Steel Heat Exchanger, 115 VAC

Lennox LD24-75-300 Gas-Fired Duct Furnaces

Tubular Aluminized or Stainless Steel Heat Exchanger:

• Tubular heat exchanger is constructed of aluminized or stainless steel for superior resistance to corrosion and oxidation
• Round surfaces create minimum air resistance and allow air to surround all surfaces for excellent heat transfer
• Curving design allows complete exposure of heating surfaces to supply air stream
• Compact design reduces space requirements in unit cabinet
• Laboratory life-cycle tested
• Condensate drain is furnished on the burner box

Inshot Burner Assembly:

• Aluminized steel inshot burner provides efficient trouble free operation
• Burner venturi mixes air and gas in correct proportion for proper combustion
• Burner assembly is removable from the unit as a single component for ease of service
• Each burner may be removed individually

Single-Stage Gas Control Valve:

• 24 volt redundant combination gas control valve combines a manual main shutoff valve, pressure regulation and automatic electric valve (dual) into one compact combination control

Direct Spark Ignition:

• Electronic direct spark ignition control provides positive and safe main burner ignition
• Occurs only when required
• Separate electronic flame sensor control assures safe and reliable operation
• Should loss of flame occur, flame sensor control will initiate 3 attempts at re-ignition before locking out unit operation

Pressure Switch:

• Pressure switch proves blower operation before allowing gas valve to open
• Combustion air inducer operates only during heating cycle

Limit Control(s):

• Factory installed and accurately located
• Limit control has fixed temperature setting
• Protects heating system from abnormal operating conditions

Combustion Air Inducer:

• Combustion air inducer prepurges heat exchanger and safely vents combustion products
• Motor has ball bearings and is thermally protected
• Pressure switch prevents unit operation in case of blockage of combustion air inlet or flue outlet
• May be rotated 90° to left or right of vertical to facilitate installation (-75-100-125-150 models only)

Venting:

• Units may be vented horizontally or vertically
• Vertical Venting - Units are approved for installation with single wall and type B-1 double wall vent pipe
• Horizontal Venting - Units are approved for installation with single wall or with Lennox-approved stainless steel vent kits

Controls:

• 115/24V transformer
• Blower timer
• Limit control
• Combination Direct Spark Ignition/Fan Timer Control
• Control board contains all necessary controls and relays to operate unit
• Fan timer control - fan on 45 seconds (fixed), fan off 150 seconds (fixed)
• Terminal strip for thermostat connections
• Diagnostic LED for troubleshooting
• Available continuous fan operation

Cabinet:

• Constructed of pre-painted steel
• Insulation keeps outer cabinet surface temperatures low
• Wiring junction box is conveniently located on outside of cabinet for easy access
• Box contains all electrical and safety controls
• 3/8” x 16 rivetnuts are located on the top of cabinet for suspending unit