Advanced Troubleshooting
THIS SECTION IS INTENDED FOR QUALIFIED REFRIGERATION SERVICE TECHNICIANS ONLY.
THE TECHNICIAN SHOULD REPEAT ALL OF THE PREVIOUS TROUBLESHOOTING STEPS
BEFORE TAKING ACTION ON THESE MORE TECHNICAL SOLUTIONS.
Evaporator Coil is Freezing
Possible Cause
Charge too low
TXV malfunctioning
High Pressure Switch Keeps Tripping Even After Checking for
Obstructions and Dirty Filters/Coils
Possible Cause
Condenser fan not operating
Defective switch
Unit Cycles On and Off More than 8 times/hr.
Possible Cause
Thermostat malfunctioning
Low suction pressure
High Pitched or Loud Rubbing Noise, Clanking or Vibration
Possible Cause
Fans loose or malfunctioning
Excessive compressor vibration
TXV malfunctioning
Replacing the Blowers
When replacing the fan or motor, replace the fan and motor as a unit. Do
not remove the motor from the impeller wheel.
IMPORTANT
Solution
Check sight glass
Check for leaks
Add refrigerant
Repair or replace
Solution
Repair or replace
Replace
Solution
Check the thermostat guide for
thermostat information
Check low pressure switch
Check pressure and adjust superheat
Solution
Repair or replace
Replace
Repair or replace
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