© 2015 Pentair Equipment Protection
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TROUBLE SHOOTING
BASIC AIR CONDITIONING TROUBLE SHOOTING CHECK LIST
1. Check manufacturer’s nameplate located on the unit for correct power supply.
2. Turn on power to the unit. The evaporator (Enclosure or “COLD” air) fan should come on. Is there
airflow?
YES, proceed to step 3.
NO, possible problem:
•
Open motor winding
•
Stuck fan motor
•
Obstructed blades
Repair or Replace
defective part
3. Check thermostat setting and adjust thermostat to the lowest setting. This should turn the
condenser fan and the compressor on. Did condenser fan and compressor come on when the
thermostat was turned on?
YES, proceed to step 4.
NO, possible problem:
•
Tripped customer door switch
•
Defective thermostat
Replace part
4. Are all fans and the compressor running? If not the unit will not cool properly.
5. Check condenser (Ambient or “HOT” air) fan for airflow. Is there airflow?
YES, proceed to step 6.
NO, possible problem:
•
Defective thermostat
•
Open motor winding
•
Stuck fan motor
•
Obstructed blades
Repair or Replace
defective part
6. Carefully check the compressor for operation - motor should cause slight vibration, and the outer
case of the compressor should be warm. Is the compressor showing signs of this?
YES, wait 5 minutes, then proceed to step 7.
NO, possible problem:
•
Defective thermostat
•
Defective capacitor
•
Defective overload
•
Defective relay
Repair or Replace
defective part
7. Make sure the coils are clean. Then check evaporator “air in” and “air out” temperatures. If the
temperatures are the same:
•
Possible loss of refrigerant
•
Possible bad valves in the
compressor
Repair or Replace
defective part
8. To check for a bad thermostat, turn power to the unit off. Remove the front cover and place both
thermostat wires onto one terminal (replace front cover for safety). This will activate the switch
in the thermostat. Turn the power on and if all fans and the compressor come on, the thermostat
needs to be replaced.