Not cooling: Codes, Causes & Fixes
A refrigerator, freezer or air conditioner that isn't cooling often has an airflow problem rather than a refrigerant problem: blocked vents inside the fridge, dust-covered condenser coils, a failed evaporator fan, a defrost fault that has iced up the coil, or dirty air filters on an AC. Give the appliance up to 24 hours after any setting change or restart before judging it. Compressor and refrigerant faults are for certified technicians only.
41Codes
3.1Average severity
24%High or critical
49%DIY-friendly
Severity distribution
Most viewed
U4
Daikin · Air Conditioner / Heat Pump
The indoor unit has lost its data link with the outdoor unit, so the system can't cool or heat.
Moderate
E6
Mitsubishi Electric · Air Conditioner / Heat Pump
The indoor unit isn't getting valid signals back from the outdoor unit over the S3 wire.
Moderate
Er dH
LG · Refrigerator / Freezer
The automatic defrost didn't finish, so frost is building up on the evaporator coil behind…
Moderate
Er IF
LG · Refrigerator / Freezer
The small fan that pushes freezer air into the door ice compartment isn't spinning, so ice…
Low
22E
Samsung · Refrigerator / Freezer
The fan that moves cold air through the fresh-food section isn't turning, most often because…
Moderate
A1
Daikin · Air Conditioner / Heat Pump
The indoor unit's circuit board couldn't load or apply its settings, so the head refuses to run.
Moderate
All codes (37)
P1
MRCOOL · Air Conditioner / Heat Pump
The outdoor unit saw supply voltage too high or too low and stopped the compressor to protect…
Moderate
P4
Midea · Air Conditioner / Heat Pump
P4 (PC 04 on newer displays): the outdoor board couldn't drive the inverter compressor…
High
P8
Mitsubishi Electric · Air Conditioner / Heat Pump
The indoor coil isn't getting colder (or warmer) than the room after the compressor starts, so…
Moderate
SY EF
Frigidaire · Refrigerator / Freezer
The main board switched on the freezer's evaporator fan but saw no sign that it's spinning.
Moderate
U0
Daikin · Air Conditioner / Heat Pump
The outdoor unit has judged the system to be low on refrigerant and stopped the compressor…
High
U4
Daikin · Air Conditioner / Heat Pump
The indoor unit has lost its data link with the outdoor unit, so the system can't cool or heat.
Moderate
U6
Mitsubishi Electric · Air Conditioner / Heat Pump
The outdoor inverter saw too much compressor current and shut down to protect the power module.
High