Instructions / Assembly

27
25 Troubleshooting (Sheet 4 of 4)
ComfortNet™
Thermostat Only
Symptoms of Abnormal Operation
(Legacy & ComfortNet™ Thermostat)
7-Segment LED
Codes
Characters
Will Alternate
Fault Description
Message Code
Possible Causes
Corrective Actions Notes & Cautions
x Air handler blower fails to operate. x Integrated control module LED display
provides indicated error code.
x ComfortNet™ thermostat “Call for
Service” icon illuminated.
x ComfortNet™ thermostat scrolls
“Check Air Handler” message.
b5
x Circulator blower
motor fails to start 10 consecutive times.
MTR
LCKD
ROTOR
b5
x Obstruction in circulator
blower housing.
x Seized circulator blower motor
bearings.
x Failed circulator blower motor.
x Check circulator blower for
obstructions. Remove and repair/replace wheel/motor if necessary.
x Check circulator blower motor
shaft rotation and motor. Replace motor if necessary.
x Turn power OFF prior to
repair
x Replace motor with
correct replacement part.
x Replace wheel with
correct replacement part.
x Air handler blower fails to operate. x Integrated control module LED display
provides indicated error code.
x ComfortNet™ thermostat “Call for
Service” icon illuminated.
x ComfortNet™ thermostat scrolls
“Check Air Handler” message.
b6
x Circulator blower
motor shuts down for over or under voltage condition.
x Circulator blower
motor shuts down due to over temperature condition on power module.
MOTOR
VOLTS
b6
x High AC line voltage to air
handler blower.
x Low AC line voltage to air
hander blower.
x High ambient temperatures.
x Check power to air handler
blower. Verify line voltage to blower is within the range specified on the air handler blower rating plate.
x See "Installation Instructions"
for installation requirements.
x Turn power OFF prior to
repair.
x Air handler blower fails to operate. x Integrated control module LED display
provides indicated error code.
x ComfortNet™ thermostat “Call for
Service” icon illuminated.
x ComfortNet™ thermostat scrolls
“Check Air Handler” message.
b7
x Circulator blower
motor does not have enough information to operate properly. Motor fails to start 40 consecutive times.
MOTOR
PARAMS
b7
x Error with integrated control
module.
x Motor has a locked rotor
condition.
x Check integrated control
module. Verify control is populated with correct shared data set. See data errors above for details.
x Check for locked rotor
condition (see error code above for details).
x Turn power OFF prior to
repair.
x Replace with correct
replacement part(s).
x Use memory card for
the specific model.
x Insert memory card
BEFORE turning power ON.
x Memory card may be
removed after data is loaded
x Turn power off before
removing memory card.
x Air handler blower operates at reduced
performance or operates on low stage when high stage is expected.
x Integrated control module LED display
provides indicated error code.
b9
x Airflow is lower than
demanded.
LOW ID
AIRFLOW
b9
x Blocked filters. x Restrictive ductwork. x Undersized ductwork.
x Check filters for blockage.
Clean filters or remove obstruction.
x Check ductwork for blockage.
Remove obstruction. Verify all registers are fully open.
x Verify ductwork is
appropriately sized for system. Resize/replace ductwork if necessary.
x Turn power OFF prior to
repair.