Installation Guide

56
TROUBLESHOOTING CODES
Message Code
• • • • •
Induced draft blower and circulator blower runs continuously. No furnace operation. Integrated control module LED display provides
E4
error code.
ComfortNet thermostat “ Call for Service” icon illuminated. ComfortNet thermostat scrolls “Check Furnace” message.
E4
•Flame sensed
when it should not be present.
IMPROPER
FLAME
E4 •
• •
Short to ground in flame sense circuit. Lingering burner flame. Slow closing gas valve.
• • •
Correct short at flame sensor or in flame sensor wiring. Check for lingering flame. Verify proper operation of gas valve. Replace if necessary.
• Turn power OFF prior to repair.
• • • •
Furnace fails to operate Integrated control module LED display provides EC error code. ComfortNet thermostat “ Call for Service” icon illuminated. ComfortNet thermostat scrolls “Check Furnace” message.
EC
• Inducer motor
overcurrent fault.
INDUCER
FAULT OR
INDUCER
LOCKOUT
EC • Lingering Inducer motor
overcurrent detected.
• •
Reset system power and verify inducer is running properly. Replace inducer or integrated control module, if necessary.
• •
No furnace operation. Integrated control module LED display provides
Ed
error code.
Ed
•Manual reset
rollout switch is open.
ROLLOUT
OPEN
Ed •
• • •
Orifice plate out of position. Blocked heat exchanger. Burners out of alignment. Defective heat exchanger.
• • • •
Line up orifice plate. Remove Blockage from heat exchanger. Line up burners. Check for flame disturbance on roll out when blower comes on.
• Turn power OFF prior to repair.
• •
No furnace operation. Integrated control module LED display provides Ef error code.
EF
• Open auxiliary
input.
AUXILIARY
OPEN
EF •
• •
Open circuit between aux in or aux out. Missing jumper. Open float switch.
• •
Install jumper. Inspect float switch.
• Turn power OFF prior to repair.
• • •
No furnace operation. Integrated control module LED display provides
E5
error code.
ComfortNet thermostat displays “Battery Power”.
E5
• Open Fuse. Not Displayed Not
Displayed
• Short in low voltage wiring • Locate and correct short in
low voltage wiring.
• •
Turn power OFF prior to repair. Replace fuse with 3- amp automotive type
• •
Normal furnace operation. Integrated control module LED display provides
E6
error code.
E6
•Flame sense
micro amp signal is low.
WEAK
FLAME
E6 •
• •
Flame sensor is coated/oxidized. Flame sensor incorrectly positioned in burner flame. Lazy burner flame due to improper gas pressure or combustion air.
• • •
Clean flame sensor if coated/oxidized. Inspect for proper sensor alignment. Check inlet air piping for blockage, proper length, elbows, and termination. Compare current gas pressure to rating plate. Adjust as needed.
• • • •
Turn power OFF prior to repair. Clean flame sensor with steel wool. See "Vent/Flue Pipe" section for piping details. See rating plate for proper gas pressure.
• •
Furnace fails to operate on high stage; furnace operates normally on low stage. Integrated control module LED display provides
E8
error code.
E8
• • •
High stage pressure switch circuit is closed at start of heating cycle. Induced draft blower is operating. Furnace is operating on low stage only
PS2
CLOSED
E8 •
•
High stage pressure switch contacts sticking. Shorts in pressure switch circuit wiring.
• •
Replace high stage pressure switch. Repair short in wiring
• •
Turn power OFF prior to repair. Replace pressure switch with correct replacement part.
Diagnostic
& Status
LED Codes
Fault
Description
Symptoms of Abnormal Operation
(Non-communicating
& ComfortNet™ Thermostat)
ComfortNet
Thermostat Only
Possible Causes Corrective Actions Notes & Cautions