Product Overview
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