Carrier Error Codes, Internal Control Fault, and LED Status Code Troubleshooting Guide

LED Troubleshooting Ð Error Code

SYMPTOM	CAUSE	REMEDY
Hardware failure.	Loss of power to control module	Check 5 amp fuse on IGC, power to unit, 24-v circuit
(LED OFF)	(IGC).	breaker, and transformer. Units without a 24-v circuit
		breaker have an internal overload in the 24-v trans-
		former. If the overload trips, allow 10 minutes for au-
		tomatic reset.
Limit switch fault.	High temperature limit switch is	Check the operation of the indoor (evaporator) fan
(LED 2 ¯ashes)	open.	motor. Ensure that the supply-air temperature rise is
		in accordance with the range on the unit nameplate.
Flame sense fault.	The IGC sensed ¯ame that	Reset unit. If problem persists, replace control board.
(LED 3 ¯ashes)	should not be present.
4 consecutive limit switch	Inadequate air¯ow to unit.	Check operation of indoor (evaporator) fan motor and
faults.		that supply-air temperature rise agrees with range on
(LED 4 ¯ashes)		unit nameplate information.
Ignition lockout.	Unit unsuccessfully attempted	Check ignitor and ¯ame sensor electrode spacing,
(LED 5 ¯ashes)	ignition for 15 minutes.	gaps, etc. Ensure that ¯ame sense and ignition wires
		are properly terminated. Verify that unit is obtaining
		proper amount of gas.
Induced-draft motor fault.	IGC does not sense that induced-	Check for proper voltage. If motor is operating, check
(LED 6 ¯ashes)	draft motor is operating.	the speed sensor plug/IGC Terminal J2 connection.
		Proper connection: PIN 1 Ð White, PI N 2 Ð Red,
		PIN 3 Ð Black.
Rollout switch fault.	Rollout switch has opened.	Rollout switch will automatically reset, but IGC will
(LED 7 ¯ashes)		continue to lockout unit. Check gas valve operation.
		Ensure that induced-draft blower wheel is properly
		secured to motor shaft. Reset unit at unit disconnect.
Internal control fault.	Microprocessor has sensed an	If error code is not cleared by resetting unit power,
(LED 8 ¯ashes)	error in the software or hardware.	replace the IGC.

If the IGC must be replaced, be sure to ground yourself to dis- sipate any electrical charge that may be present before han- dling new control board. The IGC is sensitive to static electricity and may be damaged if the necessary precautions are not taken.

IMPORTANT: Refer to Heating troubleshooting chart for addi- tional troubleshooting analysis.

LEGEND

IGC Ð Integrated Gas Unit Controller

LED Ð Light-Emitting Diode

SERVICE TRAINING

Packaged Service Training programs are an excellent way to increase your knowledge of the equip- ment discussed in this manual, including:

·	Unit Familiarization	·	Maintenance
·	Installation Overview	·	Operating Sequence

A large selection of product, theory, and skills programs are available, using popular video-based for- mats and materials. All include video and/or slides, plus companion book.

Classroom Service Training which includes ``hands-on'' experience with the products in our labs can mean increased con®dence that really pays dividends in faster troubleshooting and fewer callbacks. Course descriptions and schedules are in our catalog.

CALL FOR FREE CATALOG 1-800-962-9212

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Copyright 1998 Carrier Corporation

Manufacturer reserves the right to discontinue, or change at any time, speci®cations or designs without notice and without incurring obligations.

Book	1	4	PC 111	Catalog No. 534-721	Printed in U.S.A.	Form 48SS,SX-12SI	Pg 50	9-98	Replaces: 48SS,SX-11SI
Tab	1a	6a