Instructions / Assembly

SERVICING
82
Diagnost ic/Status LED Codes
Co m fo rtNet
Thermost a t Only
Symptoms of Abnormal Operation
(Legacy & ComfortNet™ Thermostat)
Green Ye ll ow Red Red Y1
Fault
De s cr i p ti on
Mes sage Code
Pos si ble Causes
Corrective Actions Notes & Cauti ons
Air conditioner/heat pump may appear
to be operating normally.
Integrated control module
diagnostic/status LED’s display the
indicated code.
OFF 9
Fl ashes
OFF ON if call
present;
OFF if no
call
Low Pilot
Voltage
LOW
SECOND
VOLT
09 Control detects secondary
voltage less t han 18 VAC.
Transformer overloaded.
Low line vol tage.
Check fuse.
Correct low secondary
voltage condition.
Check transformer;
replace if needed.
Turn power OFF prior
to repair.
Fault will clear if
secondary voltage rises
above 21VAC.
Replace with correct
replacement part(s).
Co mpressor is off.
Integrated control module
diagnostic/status LED’s display the
indicated code.
OFF ON ON ON if call
present;
OFF if no
call
Comp Protector
Open
Not displayed
Not
displayed
No current through run or
start windings.
Compressor run wi nding
is open.
Compressor not properly
wired to control.
Faulty compressor wiring.
Failed compressor run
capacitor.
Faulty run capacitor
wiri n g.
Check compressor;
repair/replace as
needed.
Check wiring;
repair/replace as
needed.
Check run capacitor;
replace as needed.
Turn power OFF prior
to repair.
Fault will clear after 1
no r mal cycle.
Fault may be cleared by
cycling 24VAC to
control.
Replace with correct
replacement part(s).