TROUBLESHOOTING CHART
COOLING/HP ANALYSIS CHART
Com plaint
POSSIBLE CAUSE | SYMPTOM | |
DOTS IN ANALYSIS | ||
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GUIDE INDICATE |
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"POSSIBLE CAUSE" |
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Pow er Failure
Blow n Fuse
Unbalanced Pow er, 3PH
Loose Connection
Shorted or Broken Wires
Open Fan Overload
Faulty Thermostat
Faulty Transformer
Shorted or Open Capacitor
Internal Compressor Overload Open
Shorted or Grounded Compressor
Compressor Stuck
Faulty Compressor Contactor
Faulty Fan Relay
Open Control Circuit
Low V oltage
Faulty Evap. Fan Motor
Shorted or Grounded Fan Motor
Improper Cooling A nticipator
Shortage of Refrigerant
Restricted Liquid Line
Open Element or Limit on Elec. Heater
Dirty A ir Filter
Dirty Indoor Coil
Not enough air across Indoor Coil
Too much air across Indoor Coil
Overcharge of Refrigerant
Dirty Outdoor Coil
Noncondensibles
Recirculation of Condensing Air
Infiltration of Outdoor Air
Improperly Located Thermostat
Air Flow Unbalanced
System Undersized
Broken Internal Parts
Broken Valves
Inefficient Compressor
Wrong Type Expansion V alve
Expansion Device Restricted
Oversized Expansion Valve
Undersized Expansion V alve
Expansion Valve Bulb Loose
Inoperative Expansion V alve
Loose
Faulty Reversing Valve
Faulty Defrost Control
Faulty Defrost Thermostat
Flow rator Not Seating Properly
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| No Cooling |
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| Cooling/He ating |
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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 |
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| ♦ | |
Cooling or Heating Cycle (He at Pum p) |
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System
Operating
Pre ss ure s
Test Method
Remedy
will not defrost | suction pressure | head pressure | suction pressure | head pressure |
Unit | Low | Low | High | High |
Test V oltage
Inspect Fuse Size & Type
Test V oltage
Inspect Connection - Tighten
Test Circuits With Ohmmeter
Test Continuity of Overload
Test Continuity of Thermostat & Wiring
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| Check Control Circuit w ith V oltmeter |
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| Test Capacitor |
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| Test Continuity of Overload |
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| Test Motor Windings |
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| Use Test Cord |
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| Test Continuity of Coil & Contacts |
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| Test Continuity of Coil A nd Contacts |
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| Test Control Circuit w ith Voltmeter |
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| Test V oltage |
| ♦ | Repair or Replace | |
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| • | Test Motor Windings |
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| Check Resistance of A nticipator |
• | Test For Leaks, Add Refrigerant | ||
• | • | Remove Restriction, Replace Restricted Part | |
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| Test Heater Element and Controls |
| ♦ | Inspect | |
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| ♦ | Inspect Coil - Clean |
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| ♦ | Check Blow er Speed, Duct Static Press, Filter |
| ♦ | • | Reduce Blow er Speed |
•• Recover Part of Charge
♦• Inspect Coil - Clean
•Recover Charge, Evacuate, Recharge
•Remove Obstruction to Air Flow
Check Window s, Doors, V ent Fans, Etc. Relocate Thermostat
Readjust Air Volume Dampers Refigure Cooling Load
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| • | Replace Compressor | ||
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| Test Compressor Efficiency | ||||
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| • | Test Compressor Efficiency | ||
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| ♦ | Replace V alve |
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| • | Remove Restriction or Replace Expansion Device |
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| • | Replace V alve |
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| • | Replace V alve | |||
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| Tighten Bulb Bracket | |||
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| Check Valve Operation | |
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| Tighten Bolts |
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| ♦ ♦ | Replace V alve or Solenoid | ||
♦♦ ♦ ♦ Test Control
♦ ♦ ♦ | ♦ | ♦ |
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| Test Defrost Thermostat |
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| Check Flow rator & Seat or Replace Flow rator |
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He ating Cycle Only (He at Pum p)
See Service Procedure Ref.
33