- Compressor oil charge too low or too high
- Fan blade bent, causing vibration
- Fan motor bearings loose or worn
- Tube rattling
- Condensing unit parts loose
- Low refrigerant charge
- High head-pressure
- Condenser clogged or restricted
- Non-condensable gases in system
- Liquid Line Drier restricted
- Receiver shut-off valve clogged or closed too far
- Solenoid valve leaking (in off cycle)
Wiring defective
Wiring incorrect
Fuse blown
- Control contacts open
- Overload protector tripped
- Overload protector defective
- Disconnect switch open
- Compressor motor defective
Low voltage
Wiring incorrect
Start Relay contacts stuck
Start Relay contacts welded
Start Relay defective
Incorrect Relay
Start capacitor weak
- Start capacitor defective
- Wrong start capacitor
- Defective run capacitor
- Wrong run capacitor
- Compressor motor defective
- Low voltage
- Voltage Imbalance (3-Ø)
- Defective run capacitor
- Wrong run capacitor
- Overload protector defective
- Low refrigerant charge
- Refrigerant over charge
- High head-pressure
- Bearings or pistons too tight
- Condenser clogged or restricted
- Low voltage
- Relay contacts welded
- Start winding is held in circuit too long
- Start capacitor defective
- Defective run capacitor
- Overload protector defective
- Low voltage
- Wiring incorrect
- Relay contacts open
- Defective relay
- Incorrect relay
- Start capacitor weak
- Start capacitor defective
- Incorrect start capacitor
- Defective run capacitor
- Incorrect run capacitor
- Compressor motor defective
- High head-pressure
- Bearings or pistons too tight
- Low voltage
- Relay contacts badly pitted
- Start capacitor weak
- Capillary tube, strainer or drier restricted
- Drier restricted
- Discharge line restricted
- Non-condensable gases in system
- Control contacts stuck
- Compressor inefficient
- Condenser clogged or restricted
- Refrigerant undercharged
- TEV clogged or defective
- Evaporator coil clogged by ice or dirt
- Leak in system
- Non-condensate gases in system
- Outdoor ambient too hot
- Fixture doors open too long
- Insulation defective, waterlogged or inefficient
- Unit too small for its application
- Refrigerant overcharged or undercharged
- TEV opens too wide
- Superheat adjusted too low
- Evaporator coil too small
- TEV thermostat bulb loose
- Low voltage
- Start Relay contacts sticking
- Start Relay contacts welded
- Start winding is held in circuit too long
- Start capacitor defective
- Wrong start capacitor
- Compressor short cycling
- High voltage
- Low voltage
- Wiring incorrect
- Incorrect Relay
- Start capacitor defective
- Incorrect start capacitor
- Incorrect run capacitor
- Compressor short cycling
- Compressor motor defective
- Compressor grounded
- Condenser clogged or restricted
- Condenser fan motor defective
- Refrigerant overcharged
- Discharge service valve partially closed
- Discharge line restricted
- Air and non-condensate gases in system
- Water supply shut off
- Location too hot