18-CD30D1-12
45
Installer’s Guide
the furnace three times to try and verify a flame. If no
flame is detected, the IFC will lockout for one hour.
The IFC will send an alert code to the communicating
comfort control (ERR 22) and User Interface (RETRY
LO) as well as flash its Red alert LED two times
repeatedly.
22. If a flame is detected, the IFC will start the heat
exchanger warm-up time delay for the indoor blower.
23. “IGNITION” will now be displayed in the “STATUS”
section of the User Interface menu.
24. After 45 seconds, the IFC signals the indoor blower
motor to run at the programmed ignition sequence
speed.
25. Every 1 minute, the IFC will signal the vent motor
to ramp up. The increase of the vent motor speed
allows the gas flow through the gas valve to also
be increased in 3% steps. This 3% increase will be
repeated every 1 minute until the capacity requested
is 100%. Pressure switch 3 closes at approximately
95% of capacity.
26. The IFC will also increase the indoor blower motor
speed in appropriate steps.
Indoor Blower motor operation thermostat fan switch
“CONTINUOUS” (24V Mode)
R and G comfort control contacts close signaling a con-
tinuous fan call. The continuous fan cfm is field selectable
and can be adjusted through the User Interface menu.
The factory setting is 50% of the cooling cfm selected
but can be set at 25%, 50%, 75%, or 100%. If the system
has a 2 stage outdoor unit, the setting is 50% of the 2nd
stage cooling cfm.
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Communicating
Comfort Control