Not cooling: Codes, Causes & Fixes

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

11 Fujitsu · Air Conditioner / Heat Pump Error 11: the serial data link on terminal 3 between the Fujitsu indoor and outdoor units has… Moderate 126 Trane · Air Conditioner / Heat Pump 126 on a Trane ComfortLink II thermostat: it lost its data link to the furnace, air handler… Moderate 21E Samsung · Refrigerator / Freezer The freezer's evaporator fan isn't reporting any rotation, usually because ice has trapped… Moderate 22E Samsung · Refrigerator / Freezer The fan that moves cold air through the fresh-food section isn't turning, most often because… Moderate 23E Samsung · Refrigerator / Freezer The fan that cools the condenser and compressor behind the bottom rear panel has stopped… High 434 Lennox · Air Conditioner / Heat Pump The Lennox outdoor control can't talk to the inverter drive that runs the variable-speed… Moderate 51 Fujitsu · Air Conditioner / Heat Pump Error 51: the indoor fan ran far slower than commanded for about a minute, so the Fujitsu unit… Moderate 5E Samsung · Refrigerator / Freezer The sensor on the fresh-food evaporator reads open or shorted, so the board can't tell when… Low 84E Samsung · Refrigerator / Freezer The inverter tried to spin the compressor, but it didn't turn or ran outside its limits, so… High 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 A3 Daikin · Air Conditioner / Heat Pump A3 means condensate is backing up in the indoor unit's drain pan and the float switch has… Moderate CH05 LG · Air Conditioner / Heat Pump CH05: the LG indoor unit hears nothing back from the outdoor unit, so the compressor… Moderate CH10 LG · Air Conditioner / Heat Pump CH10: the indoor unit's fan motor isn't turning or isn't reporting its speed, so the unit shuts… Moderate CH21 LG · Air Conditioner / Heat Pump CH21: the outdoor inverter's power module saw a dangerous current peak and cut power… High CH38 LG · Air Conditioner / Heat Pump LG's protection stopped the system because the refrigerant level or pressure looks too low. High E1 Gree · Air Conditioner / Heat Pump E1: refrigerant pressure on the high side got too high and the Gree unit stopped the compressor… Moderate E101 Samsung · Air Conditioner / Heat Pump The indoor unit waited too long for the outdoor unit to answer on the F1/F2 link and shut… Moderate E201 Samsung · Air Conditioner / Heat Pump E201: after power-up the outdoor unit couldn't find and register its indoor unit(s), so it… Moderate E5 Gree · Air Conditioner / Heat Pump E5: the Gree unit drew more current than allowed – often because supply voltage sagged… 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 E6 Gree · Air Conditioner / Heat Pump E6 means the Gree indoor and outdoor units have lost their data link, so cooling and heating… Moderate E7 Daikin · Air Conditioner / Heat Pump The outdoor fan failed to spin up, or its speed signal went wrong, so the outdoor unit shut… Moderate EC Midea · Air Conditioner / Heat Pump EC: in cooling, the indoor coil didn't get colder after the compressor started – the unit… High EL01 MRCOOL · Air Conditioner / Heat Pump The MRCOOL indoor and outdoor units have stopped exchanging data, so the compressor won't run. Moderate Er 22 LG · Refrigerator / Freezer LG's board found a fault in the compressor relay circuit, so the compressor isn't starting… High Er dH LG · Refrigerator / Freezer The automatic defrost didn't finish, so frost is building up on the evaporator coil behind… Moderate Er FF LG · Refrigerator / Freezer LG's freezer fan motor isn't operating normally; frost around the blade is the usual reason it… Moderate Er IF LG · Refrigerator / Freezer The small fan that pushes freezer air into the door ice compartment isn't spinning, so ice… Low Er rF LG · Refrigerator / Freezer The fan that circulates air inside LG's fresh-food section isn't running normally, often… Moderate H1 Frigidaire · Refrigerator / Freezer A compartment has been too warm for too long; it's an alarm about temperature, not a specific… Moderate