40
TROUBLESHOOTING CHART
Symptom
LED Status
Fault Description
Corrective Actions
Furnace fails to operate
Grounding fault
Poor neutral connection
Verify neutral wire connection to furnace &
continuity to ground source
Furnace fails to operate
Open roll out switch
Check for correct gas pressure
Check for correct burner alignment
Check for and correct burner restriction
Furnace fails to operate
Data not yet on network
Populate shared data set using memory card
Operation different 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 fails to operate
Furnace lockout due to an
excessive number of ignition
“retries” (3 total)
Failure to establish flame
Loss of flame 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
Verify proper induced draft blower performance
Furnace fails to operate
Pressure switch
circuit is closed at start of
heating cycle
Pressure switch
contacts sticking
Short in pressure switch circuit
wiring
Replace pressure switch
Repair short in wiring
Induced draft blower
runs continuously with no
furnace operation
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 improperly connected
wiring
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
Insufficient 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 performance
Correct speed or replace blower motor if
necessary
Tighten or correct wiring connection
