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10.0 DIAGNOSTICS AND TROUBLESHOOTING
10.7 Service Analyzer Chart (cont.)
Diagnostics
FLOODING
SYMPTOM
POSSIBLE CAUSE
CHECK OR REMEDIES
Superheat and
suction pressure
fluctuate (EXV is
hunting)
Oversized EXV
Install correct EXV
Unequal refrigerant flow through evaporator circuit Ensure suction line thermistor is in correct location in a
clean section of copper pipe
Moisture freezing and partially blocking EXV
Recover refrigerant, change filter-drier, evacuate system
and recharge
TXV does not
regulate at all
External equalizer line not connected or line
plugged
Connect equalizer line in proper location, or remove any
blockage
Sensing bulb lost its operating charge
Replace TXV
Valve body damaged during soldering or by im
-
proper installation
Replace the TXV
10.8 Troubleshooting Tips
COOLING MODE
TROUBLESHOOTING TIPS
SYSTEM
PROBLEM
INDICATORS
DISCHARGE
PRESSURE
SUCTION
PRESSURE
SUPERHEAT
Normal: 5o-15oF
[2.8o-8.3oC]
SUBCOOLING
Normal: See
Charging Chart
COMPRESSOR
AMPS
Overcharge
High
High
Low
High
High
Undercharge
Low
Low
High
Low
Low
Liquid Restriction
(Filter 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 Sensing
Bulb Charge Lost or
Bad Thermistor
Low
Low
High
High
Low
Poorly Insulated
Indoor TXV Sensing
Bulb or Thermistor.
Bad Thermistor.
High
High
Low
Low
High
Summary of Contents for A17 Series
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