Carrier 48GC04 Service And Maintenance Instructions page 35

LED
FLASH DESCRIPTION
CODE
On Normal Operation
Off Hardware Failure
2 Flashes Limit Switch Fault
3 Flashes Flame Sense Fault
Four Consecutive Limit
4 Flashes
Switch Fault
5 Flashes Ignition Fault
6 Flashes Induced Draft Motor Fault
7 Flashes Rollout Switch Lockout
8 Flashes Internal Control Lockout
9 Flashes Temporary Software Lockout No gas heating.
LEGEND
IGC — Integrated Gas Unit Control
LED — Light-Emitting Diode
NOTES:
1. There is a 3-second pause between alarm code displays.
2. If more than one alarm code exists, all applicable alarm codes will
be displayed in numerical sequence.
3. Alarm codes on the IGC will be lost if power to the unit is
interrupted.
Table 13 — IGC Board LED Alarm Codes
ACTION TAKEN BY
CONTROL
— —
No gas heating. —
Gas valve and igniter Off. Limit switch closed, or heat
Indoor fan and inducer On. call (W) Off.
Flame sense normal.
Indoor fan and inducer On.
Power reset for LED reset.
Heat call (W) Off. Power
No gas heating.
reset for LED reset.
Heat call (W) Off. Power
No gas heating.
reset for LED reset.
If heat off: no gas heating.
Inducer sense normal, or
If heat on: gas valve Off and
heat call (W) Off.
inducer On.
Gas valve and igniter Off.
Power reset.
Indoor fan and inducer On.
No gas heating. Power reset.
1 hour auto reset, or power
reset.
35
RESET METHOD
—
Loss of power to the IGC. Check 5 amp fuse
on IGC, power to unit, 24V circuit breaker,
transformer, and wiring to the IGC.
High temperature limit switch is open. Check
the operation of the indoor (evaporator) fan
motor.
Ensure that the supply-air temperature rise is
within the range on the unit name-plate.
Check wiring and limit switch operation.
The IGC sensed a flame when the gas valve
should be closed. Check wiring, flame
sensor, and gas valve operation.
4 consecutive limit switch faults within a
single call for heat. See Limit Switch Fault.
Unit unsuccessfully attempted ignition for 15
minutes. Check igniter and flame sensor
electrode spacing, gaps, etc. Check flame
sense and igniter wiring. Check gas valve
operation and gas supply. Check gas valve
connections to IGC terminals. BRN lead
must be on Pin 11.
Inducer sense On when heat call Off, or
inducer sense Off when heat call On.
Check wiring, voltage, and operation of IGC
motor. Check speed sensor wiring to IGC.
Rollout switch has opened. Check gas valve
operation. Check induced-draft blower wheel
is properly secured to motor shaft.
IGC has sensed internal hardware or
software error. If fault is not cleared by
resetting 24 v power, replace the IGC.
Electrical interference is disrupting the IGC
software.
PROBABLE CAUSE