S9240F1004 Modulating Hot Surface
Ignition Integrated Furnace Control
The S9240F1004 Integrated Furnace Control (IFC) is
designed specifically to work with a Lennox G71MPP variable
firing rate, high efficiency furnace. It provides gas ignition,
safety shutoff, and variable speed fan control with multi-firing
rate gas heating and up to 2-stage electric cooling
The S9240F1004 provides the following features:
• Monitors a single stage or 2-stage conventional low
voltage thermostat for requests for heat, cool, or fan.
• Monitors an input provided for connection to a
thermostat with a dehumidification output or Harmony
III Zone Control.
• Provides three stage furnace input rate control when
operating with a conventional single stage thermostat.
• Provides 2-stage or modulating furnace input rate
control based on field selected option when operating
with a conventional 2-stage thermostat.
• Manages ignition of a main burner flame up to 400,000
BTU per hour using a 95 V hot surface igniter.
• Monitors the appliance pressure, limit, and rollout
switches and generate control actions as
• Controls the 24 Vac Honeywell amplified gas/air gas
• Controls a 3-phase 120 Vac inducer motor (Fasco
• Controls the Regal Beloit 3.0 ECM circulator motor and
• Controls single stage or 2-stage cooling equipment.
• Controls a 120 Vac humidifier output and a 120 Vac
• Operates with 120 Vac single phase, 60 Hz power
• Uses a 7-segment LED display to communicate error
• Provides field selectable DIP switches to select field
• Provides on-board jumpers that can be clipped to
• Provides Field Test Mode and Diagnostic Recall Mode
• Stores the 10 most recent error codes, which are
Automatic Ignition Systems
Model 92B1 or other with identical voltage/frequency
curve) and blower assembly based on heat demand
and other parameters.
blower based on defined appliance CFM profiles
and/or a discharge air sensor signal.
The outdoor unit is controlled directly by the 24 Vac
conventional thermostat inputs. The IFC manages the
circulator speed based on cool demand and other
code and status information. A single on board button
is provided to generate the desired information
specific control operating parameters such as type of
thermostat, delay timings, and fan operating
permanently enable 2-stage cooling, heat pump
compatibility, dehumidification sequences, and define
appliance characteristics for field replacement
to assist the installation/service technician.
accessible by the service technician in Diagnostic