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TROUBLESHOOTING CHART
Complaint
System
Operating
Pressures
POSSIBLE CAUSE
DOTS IN ANALYSIS
GUIDE INDICATE
"POSSIBLE CAUSE"
SYMPTOM
System will not start
Compressor will not start - fan runs
Comp. and Cond. Fan will not start
Evaporator fan will not start
Condenser fan will not start
Compressor runs - goes off on overload
Compressor cycles on overload
System runs continuously - little cooling/htg
Too cool and then too warm
Not cool enough on warm days
Certain areas too cool, others too warm
Compressor is noisy
System runs - blows cold air in heating
Unit will not terminate defrost
Unit will not defrost
Low suction pressure
Low head pressure
High suction pressure
High head pressure
Test Method
Remedy
See Service Procedure Ref.
Pow er Failure
•
Test Voltage S-1
Blown Fuse
•••
Inspect Fuse Size & Type S-1
Unbalanced Power, 3PH
•••
Test Voltage S-1
Loose Connection
•••
Inspect Connection - Tighten S-2, S-3
Shorted or Broken Wires
••••••
Test Circuits With Ohmmeter S-2, S-3
Open Fan Overload
••
Test Continuity of Overload S-17A
Faulty Thermostat
••• •
Test Continuity of Thermostat & Wiring S-3
Faulty Transformer
••
Check Control Circuit w ith Voltmeter S-4
Shorted or Open Capacitor
•••••
Test Capacitor S-15
Internal Compressor Overload Open
•
♦
Test Continuity of Overload S-17A
Shorted or Grounded Compressor
••
Test Motor Windings S-17B
Compressor Stuck
•••
♦
Use Test Cord S-17D
Faulty Compressor Contactor
•••
Test Continuity of Coil & Contacts S-7, S-8
Faulty Fan Relay
•
Test Continuity of Coil And Contacts S-7
Open Control Circuit
•
Test Control Circuit with Voltmeter S-4
Low Voltage
•••
Test Voltage S-1
Faulty Evap. Fan Motor
••
♦
Repair or Replace S-16
Shorted or Grounded Fan Motor
••
Test Motor Windings S-16
Improper Cooling Anticipator
••
Check Resistance of Anticipator S-3B
Shortage of Refrigerant
••
♦
••
Test For Leaks, Add Refrigerant S-101,103
Restricted Liquid Line
•• •• •
Remove Restriction, Replace Restricted Part S-112
Open Element or Limit on Elec. Heater
♦♦
Test Heater Element and Controls S-26,S-27
Dirty Air Filter
••• •
♦
Inspect Filter-Clean or Replace
Dirty Indoor Coil
••• •
♦
Inspect Coil - Clean
Not enough air across Indoor Coil
••• •
♦
Check Blower Speed, Duct Static Press, Filter S-200
Too much air across Indoor Coil
♦
•
Reduce Blower Speed S-200
Overcharge of Refrigerant
•• •
♦
••
Recover Part of Charge S-113
Dirty Outdoor Coil
•• •
♦
•
Inspect Coil - Clean
Noncondensibles
••
♦
•
Recover Charge, Evacuate, Recharge S-114
Recirculation of Condensing Air
•• •
Remove Obstruction to Air Flow
Infiltration of Outdoor Air
•••
Check Windows, Doors, Vent Fans, Etc.
Improperly Located Thermostat
••
Relocate Thermostat
Air Flow Unbalanced
••
Readjust Air Volume Dampers
System Undersized
••
Refigure Cooling Load
Broken Internal Parts
•
♦
Replace Compressor S-115
Broken Valves
•• ••
Test Compressor Efficiency S-104
Inefficient Compressor
•
♦
••
Test Compressor Efficiency S-104
Wrong Type Expansion Valve
••• • ••
♦
Replace Valve S-110
Expansion Device Restricted
••• • •• •
Remove Restriction or Replace Expansion Device S-110
Oversized Expansion Valve
••
Replace Valve
Undersized Expansion Valve
••• • •
Replace Valve
Expansion Valve Bulb Loose
••
Tighten Bulb Bracket S-105
Inoperative Expansion Valve
•• •
Check Valve Operation S-110
Loose Hold-down Bolts
•
Tighten Bolts
Faulty Reversing Valve
•
♦♦♦ ♦♦♦
Replace Valve or Solenoid S-21, 122
Faulty Defrost Control
•
♦♦♦♦♦ ♦
Test Control S-24
Faulty Defrost Thermostat
♦♦♦♦♦♦♦
Test Defrost Thermostat S-25
Flowrator Not Seating Properly
•••
Check Flowrator & Seat or Replace Flowrator S-111
• Cooling or Heating Cycle (Heat Pump)
♦
COOLING/HP ANALYSIS CHART
No Cooling
Unsatisfactory
Cooling/Heating
Heating Cycle Only (Heat Pump)