47
Diagnostics
DIAGNOSTICS
COOLING MODE
TROUBLESHOOTING TIPS
SYSTEM
PROBLEM
INDICATORS
DISCHARGE
PRESSURE
SUCTION
PRESSURE
SUPERHEAT
Normal: 5°–15°F
[-15° – -9°C]
SUBCOOLING
Normal: See
Charging Chart
COMPRESSOR
AMPS
Overcharge
High
High
Low
High
High
Undercharge
Low
Low
High
Low
Low
Liquid Restriction
(Drier)
Low
Low
High
High
Low
Low Indoor Airflow
Low
Low
Low
Low
Low
Dirty Outdoor Coil
High
High
Low
Low
High
Low Outdoor
Ambient Temperature
Low
Low
High
High
Low
Inefficient
Compressor
Low
High
High
High
Low
Indoor TXV Feeler
Bulb Charge Lost
Low
Low
High
High
Low
Poorly Insulated
Indoor Sensing Bulb
High
High
Low
Low
High
HEATING MODE
TROUBLESHOOTING TIPS
SYSTEM
PROBLEM
INDICATORS
DISCHARGE
PRESSURE
SUCTION
PRESSURE
SUPERHEAT
Normal: 5°–15°F
[-15° – -9°C]
SUBCOOLING
Normal: See
Charging Chart
COMPRESSOR
AMPS
Overcharge
High
High
OK
High
High
Undercharge
Low
Low
OK or High
Low
Low
Liquid Restriction
(Drier)
Low
Low
High
High
Low
Low Outdoor Airflow
Low
Low
Low
Low
Low
Dirty Indoor Coil
High
High
Low
Low
High
Low Indoor Ambient
Temperature
Low
Low
OK
High
Low
Inefficient
Compressor
Low
High
High
High
Low
Outdoor TXV Feeler
Bulb Charge Lost
Low
Low
High
High
Low
Poorly Insulated
Outdoor Sensing
Bulb
High
High
Low
Low
High