Install Instructions

46
T ROUBLESHOOTING C HART
Symptom LED Status Fault Description Corrective Actions
Furnace operates at reduced
performance or operates on low
stage when high stage is expected

Airflow is lower than demanded
Check filters for blockage, clean filters or remove
obstruction
Check ductwork for blockage, remove obstruction and verify
all registers are f ully open
Verify ductwork is appropriately sized for system, resize
and/or replace ductwork if necessary
Furnace f ails to operate

Grounding fault
Poor neutral connection
Verify neutral wire connection to furnace & continuity to
ground source
Furnace f ails to operate

Open roll out switch
Check for correct gas pressure
Check for correct burner alignment
Check for and correct burner restriction
Furnace f ails to operate

Data not yet on network Populate shared data set using memory card
Operation dif ferent than expected
or no operation

Invalid memory card data
Verify shared data set is correct for the specific model, re-
populate data using correct memory card if required
Furnace f ails to operate

Furnace lockout due to an excessive
number of ignition “retries” (3 total)
Failure to establish flame
Loss of f lame after establishment
Locate and correct gas interruption
Check front cover pressure switch operation and verify
proper drainage (hose, wiring, contact operation), correct if
necessary
Replace or realign igniter
Check flame sense signal, sand sensor if coated and/or
oxidized
Check flue piping for blockage, proper length, elbows, and
termination
Verif
y
p
ro
p
er induced draft blower
p
erformance
Furnace f ails to operate

Low stage pressure switch circuit is
closed at start of heating cycle
Low stage pressure switch contacts
sticking
Short in
p
ressure switch circuit wirin
g
Replace low stage pressure switch
Repair short in wiring
Induced draft blower
runs continuously with no furnace
operation

Low stage pressure switch circuit is not
closed
Pressure switch hose blocked
pinched, or connected improperly
Blocked flue and/or inlet air pipe,
blocked drain system or weak induced
draft blower
Incorrect pressure switch set point or
malfunctioning switch contacts
Loose or im
p
ro
p
erl
y
connected wirin
g
Inspect pressure switch hose, repair/replace if necessary
Inspect flue and/or inlet air piping for blockage, proper
length, elbows, and termination
Check drain system, correct as necessary
Check induced draft blower performance, correct as
necessary
Check pressure switch operation, replace as needed
Tighten or correct wiring connection
Circulator blower runs
continuously
No furnace operation

Primary limit circuit is open
Insuf f icient conditioned air over the
heat exchanger
Blocked filters, restrictive ductwork,
improper circulator blower speed, or
failed circulator blower motor
Loose or improperly connected wiring
in high limit circuit
Check filters and ductwork for blockage
Clean filters or remove obstruction
Check circulator blower speed and perf ormance
Correct speed or replace blower motor if necessary
Tighten or correct wiring connection