Instructions / Assembly

SERVICING
78
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Symptoms of Abnormal Operation
(Legacy & ComfortNet™ Thermostat)
Diagnostic/Status LED Codes
Faul t
Description
Comf or t N e t ™
Thermostat Only
Possible Causes
Corrective Actions Notes & Cautions
Green Yel lo w Red Red Y1 Me ss age Code
• Very long run time. • Four consecutive compressor protector
trips with average run time between trips greater than 3 hours.
• Compressor operating at high speed
and outdoor fan operating at low speed
• Integrated control module
diagnostic/status LED’s display the indicated code.
OFF 1 Flash OFF ON if call
present;
OFF if no
call
• Low Side Fault. LOW S IDE
FAULT
01 • Low refrigerant charge.
• Restriction in liquid line. • Indoor blower motor
failure.
• Indoor thermostat set
extremely low.
• Verify refrigerant
charge; adjust as needed.
• Check for restricted
liquid line; repair/replace as needed.
• Check indoor blower
motor; repair/replace as needed.
• Check indoor
thermostat setting.
• Turn power OFF prior
to repair.
• Fault will clear after 30
consecutive normal cycles.
• Faul t may be cleared by
cycling 24VAC to control.
• Replace with correct
replacement part(s).
• Compressor a nd outdoor fan are off. • Thermostat demand is present. • Integrated control module
diagnostic/status LED’s display the indicated code.
ON 1 Flash OFF ON if call
present;
OFF if no
call
• Low Pressure
CO Trip.
LPS OPEN 01
• Low refrigerant charge. • Restriction in liquid line. • Indoor blower motor
failure.
• Indoor thermostat set
extremely low.
• Verify refrigerant
charge; adjust as needed.
• Check for restricted
liquid line; repair/replace as needed.
• Check indoor blower
motor; repair/replace as needed.
• Check low pressure
switch; repair/replace as needed.
• Check indoor
thermostat setting.
• Turn power OFF prior
to repair.
• Replace with correct
replacement part(s).
• Compressor a nd outdoor fan are off. • Low pressure switch trip 3 times within
same thermostat demand.
• Thermostat demand is present. • Integrated control module
diagnostic/status LED’s display the indicated code.
• ComfortNet™ thermostat “Call for
Service” icon illuminated.
• ComfortNet™ thermostat scrolls
“Check Air Conditioner” or “Check Heat Pump” message.
ON 1 Flash ON ON if call
present;
OFF if no
call
• LPCO Lockout
(3 Trips).
LPS
LOCKOUT
01
• Low refrigerant charge. • Restriction in liquid line. • Indoor blower motor
failure.
• Indoor thermostat set
extremely low.
• Verify refrigerant
charge; adjust as needed.
• Check for restricted
liquid line; repair/replace as needed.
• Check indoor blower
motor; repair/replace as needed.
• Check low pressure
switch; repair/replace as needed.
• Check indoor
thermostat setting.
• Turn power OFF prior
to repair.
• Must clear fault by
cycling 24VAC to control.
• Replace with correct
replacement part(s).