Instructions / Assembly

25
25 Troubleshooting (Sheet 2 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 no signal.
x ComfortNet™ thermostat “Call for
Service” icon illuminated
x ComfortNet™ thermostat scrolls
“Check Air Handler” message
No Display
x No 208/230 volt power
to air handler blower or no 24 volt power to integrated control module
x Blown fuse or circuit
breaker
x Integrated control
module has an internal fault.
INTERNAL
FAULT
EE
x Manual disconnect switch OFF
or 24 volt wire improperly connected or loose
x Blown fuse or circuit breaker x Integrated control module has
an internal fault
x Assure 208/230 volt and 24
volt power to air handler blower and integrated control module.
x Check integrated control
module fuse (3A). Replace if necessary.
x Check for possible shorts in
208/230 volt and 24 volt circuits. Repair as necessary.
x Replace bad integrated
control module.
x Turn power OFF prior to
repair.
x Replace integrated
control module fuse with 3A automotive fuse.
x Replace integrated
control module with correct replacement part
x Read precautions in
“Electrostatic Discharge” section of manual.
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.
d0
x Data not yet on
network.
NO NET
DATA
d0
x Air handler blower does not
contain any shared data.
x Populate shared data set
using memory card.
x Turn power OFF prior to
repair
x Use memory card for
the specific model.
x Insert memory card
BEFORE turning power ON. Memory card may be removed after data is loaded.
x Error code will be
cleared once data is loaded.
x Turn power off before
removing memory card
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.
d1
x Invalid data on
network.
INVALID
DATA
d1
x Air handler blower does not
contain an appropriate shared data set.
x Populate correct shared data
set using memory card.
x Turn power OFF prior to
repair
x Use memory card for
the specific model.
x Insert memory card
BEFORE turning power ON. Memory card may be removed after data is loaded.
x Error code will be
cleared once data is loaded.
x Operation different than expected or no
operation.
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.
d4
x Invalid memory card
data.
INVALID
MC DATA
d4
x Shared data set on memory
card has been rejected by integrated control module
x Verify shared data set is
correct for the specific model. Re-populate data using correct memory card if required.
x Turn power OFF prior to
repair
x Use memory card for
the specific model.
x Insert memory card
BEFORE turning power ON. Memory card may be removed after data is loaded.
x Error code will be
cleared once data is loaded.
x Turn power off before
removing memory card