Installations Instructions

60
TROUBLESHOOTING CODES
Message Code
Fu rn ace f ails to operate.
Integrated control module LED
display provides
b5
error code.
ComfortNet thermostat “Call for
Service icon illuminated.
ComfortNet thermostat scrolls
Check Furnace” message.
b5
Circulator blower
motor fails to
start 10
consecutive
times.
MTR LCKD
ROT OR
b5
Obstruction in circulator blower
housing.
Seized circulator blower motor
bearings.
Failed circulator blower motor.
Check circulator blower f or
obstructions. Remove and
repair/replace wheel/motor if necessary.
Check circulator blower motor shaf t
rotation and motor. Replace motor if
necessary.
Turn power OFF prior to repair
Replace motor with correct
replacement part.
Replace wheel with correct
replacement part.
Fu rn ace f ails to operate.
Integrated control module LED
display provides
b6
error code.
ComfortNet thermostat “Call for
Service icon illuminated.
ComfortNet thermostat scrolls
Check Furnace” message.
b6
Circulator blower
motor shuts
down f or over or
under voltage
condition.
Circulator blower
motor shuts
down due to
over temperature
condition on
power module.
MOTOR
VOLTS
b6
High AC line voltage to f urnace.
Low AC line voltage to f urnace.
High ambient temperatures.
Check power to furnace. Verify line
voltage to furnace is within the range
specified on the furnace rating plate.
See "Product Description" and
"Location Requirements &
Considerations" for furnace
installation requirements.
Turn power OFF prior to repair.
Fu rn ace f ails to operate.
Integrated control module LED
display provides
b7
error code.
ComfortNet thermostat “Call for
Service icon illuminated.
ComfortNet thermostat scrolls
Check Furnace” message.
b7
Circulator blower
motor does not
have enough
information to
operate properly.
Motor fails to
start 40
consecutive
times.
MOTOR
PARAMS
b7
Error with integrated control
module.
Motor has a locked rotor condition.
Check integrated control module.
Verify control is populated with
correct shared data set. See data
errors above for details.
Check for locked rotor condition
(see error code above for details).
Turn power OFF prior to repair.
Replace with correct replacement
part(s).
Use memory card for the specific
model.
Furnace operates at reduced
performance.
Integrated control module LED
display provides
b9
error code.
b9
Airflow is lower
than demanded.
LOW ID
AIRFLOW
b9
Blocked filters.
Restrictive ductwork.
Undersized ductwork.
Check f ilters for blockage. Clean filters
or remove obstruction .
Check ductwork for blockage. Remove
obstruction. Verif y all registers are fully
open.
Verify ductwork is appropriately sized
for system. Resize/replace ductwork if
necessary.
Turn power OFF prior to repair.
Diagnostic
& Status
LED Codes
Fault
Description
Symptoms of Abnormal Operation
(Non-communicating
& ComfortNet T hermostat)
ComfortNet
Thermostat Only
Possible Causes Corrective Actions Notes & Cautions