52
Table 17 – IGC Board LED Alarm Codes
LED
FLASH
CODE
DESCRIPTION
ACTION TAKEN BY
CONTROL
RESET METHOD
PROBABLE CAUSE
On
Normal Operation
—
—
—
Off
Hardware Failure
No gas heating.
—
Loss of power to the IGC. Check 5 amp
fuse on IGC, power to unit, 24V circuit
breaker, transformer, and wiring to the
IGC.
2
Flashes Limit Switch Fault
Gas valve and igniter
Off.
Indoor fan and inducer
On.
Limit switch closed,
or heat call (W) Off.
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. Check/clean return air filters.
Check burner assembly manifold pressure
to ensure proper firing rate.
3
Flashes Flame Sense Fault
Indoor fan and inducer
On.
Flame sense normal.
Power reset for LED
reset.
The IGC sensed a flame when the gas
valve should be closed. The minimum
flame sensing microamps is 0.5 ma.
Check wiring, flame sensor, and gas valve
operation.
4
Flashes
Four Consecutive Limit
Switch Fault
No gas heating.
Heat call (W) Off.
Power reset for LED
reset.
4 consecutive limit switch faults within a
single call for heat. See Limit Switch Fault.
5
Flashes Ignition Fault
No gas heating.
Heat call (W) Off.
Power reset for LED
reset.
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.
6
Flashes
Induced Draft Motor
Fault
If heat off: no gas
heating.
If heat on: gas valve
Off and inducer On.
Inducer sense
normal, or heat call
(W) Off.
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. Check to ensure Hall Effect wires are
not rubbing against cabinet sheet metal.
7
Flashes Rollout Switch Lockout
Gas valve and igniter
Off.
Indoor fan and inducer
On.
Power reset.
Rollout switch has opened. Check gas
valve operation. Check induced-draft
blower wheel is properly secured to motor
shaft.
8
Flashes Internal Control Lockout No gas heating.
Power reset.
IGC has sensed internal hardware or
software error. If fault is not cleared by
resetting 24 v power, replace the IGC.
Check gas valve connections to IGC
terminals. BRN lead must be on Pin 11.
Check that W1, W2 and Com are correctly
connected to the gas valve terminals.
9
Flashes
Temporary Software
Lockout
No gas heating.
1 hour auto reset, or
power reset.
Electrical interference is disrupting the
IGC software.
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.
48H
C
Summary of Contents for 48HC D17 Series
Page 77: ...77 APPENDIX IV WIRING DIAGRAMS C12616 Fig 77 48HC D17 D28 Power Diagram 208 230 3 60 48HC...
Page 78: ...78 APPENDIX IV WIRING DIAGRAMS C12617 Fig 78 48HC D17 D28 Power Diagram 460 3 60 48HC...
Page 79: ...79 APPENDIX IV WIRING DIAGRAMS C12618 Fig 79 48HC D17 D28 Power Diagram 575 3 60 48HC...
Page 86: ...86 APPENDIX IV WIRING DIAGRAMS C13767 Fig 86 RTU OPEN Wiring Diagram 48HC...
Page 87: ...87 APPENDIX IV WIRING DIAGRAMS C13768 Fig 87 RTU OPEN Wiring Diagram with Humidi MiZer 48HC...
