28
Troubleshooting Chart
Symptom
LED Status
Fault Description
Corrective Actions
Normal Operation
I dL
Stand-by Mode. Normal Operation
None
Furnace Fails to Operate
EEE
Internal Control fault
Replace control board
Locate and correct gas interruption
Replace or realign igniter
Check flame sense signal, clean sensor if coated or
oxidized
Check flue piping for blockage, proper length, elbows,
and termination
Verify proper induced draft blower performance
Draft Inducer pressure switch circuit is closed at
start of heating cycle
Draft Inducer pressure switch contacts sticking
Short in pressure switch circuit wiring
Draft Inducer pressure switch circuit is not closed
Pressure switch hose blocked pinched, or
connected improperly
Inspect flue and/or inlet air for blockage, proper length,
elbows, and termination
Check induced draft blower performance, correct as
necessary
Incorrect pressure switch set point or
malfunctioning switch contacts
Check pressure switch operation, replace as needed
Loose or improperly connected wiring
Tighten or correct wiring connection
Primary limit circuit is open
Check filters and ductwork for blockage Clean filters or
remove obstruction
Insufficient conditioned air over the heat
exchanger
Check circulator blower speed and performance
Blocked filters, restrictive ductwork, improper
circulator blower speed, or failed circulator
blower motor
Correct speed or replace blower motor if necessary
Loose or improperly connected wiring in high
limit circuit
Tighten or correct wiring connection
Flame sensed with no call for heat
Correct short at flame sensor or in flame sensor wiring
Short to ground in flame sense circuit
Lingering burner flame Slow closing gas valve
Open fuse
Replace fuse
Short in low voltage wiring
Locate and correct short in low voltage wiring
Flame sense micro amp signal is minimal
Flame sensor is coated/oxidized
Flame sensor incorrectly positioned in burner
fame
Check inlet air for blockage
Compare current gas pressure to rating plate and
adjust as needed
Problem with igniter circuit
Check and correct wiring from integrated control module
to igniter
Improperly connected or shorted igniter
Poor unit ground
Igniter relay fault on integrated control module
Check igniter output from control, replace if necessary
Furnace Operates but
shows weak flame signal
fault
EE6
Clean flame sensor if coated or oxidized Inspect for
proper flame sensor alignment
Lazy burner flame due to improper gas pressure
or combustion air
Induced draft blower runs
continuously with no furnace
operation
EE2
Inspect pressure switch hose, repair/replace if
necessary
Blocked flue and/or inlet air or weak induced draft
blower
Furnace fails to operate
EE0
Furnace lockout due to an excessive number of
ignition “retries” (3 total)
Failure to establish flame
Loss of flame after establishment
Furnace fails to operate
EE1
Replace Draft Inducer pressure switch. Repair short in
wiring
Circulator blower runs
continuously
No furnace operation
EE3
Induced draft blower and
circulator blower runs
continuously
No furnace operation
EE4
Check for lingering or lazy flame Verify proper operation
of gas valve
No furnace operation
EE5
Furnace fails to operate
EE7
Diagnose and replace shorted igniter as needed Verify
and correct unit ground wiring if needed
