Carrier WeatherExpert 48LC Series Service And Maintenance Instructions page 31

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 14 — IGC Board LED Alarm Codes
ACTION TAKEN BY
CONTROL
—
No gas heating.
Gas valve and igniter Off.
Indoor fan and inducer On.
Indoor fan and inducer On.
No gas heating.
No gas heating.
If heat off: no gas heating.
If heat on: gas valve Off and
inducer On.
Gas valve and igniter Off.
Indoor fan and inducer On.
No gas heating.
31
RESET METHOD
—
—
Limit switch closed, or heat
call (W) Off.
Flame sense normal. Power
reset for LED reset.
Heat call (W) Off. Power reset
for LED reset.
Heat call (W) Off. Power reset
for LED reset.
Inducer sense normal, or heat
call (W) Off.
Power reset.
Power reset.
1 hour auto reset, or power
reset.
PROBABLE CAUSE
—
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 nameplate.
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.