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Carrier Air Conditioner CL / dF Error Code
Filter reminder or defrost in progress on Carrier air conditioners.
CarrierAll Carrier air conditioner codes
Neither is a fault. CL is the reminder to clean the filters (nF asks you to replace them). dF shows while a heat pump defrosts its outdoor coil: the indoor and outdoor fans stop for up to 15 minutes while the compressor keeps going.
Compatible models
Status messages on Carrier 40MHH high-wall ductless units; dF appears on the heat pump (40MHHQ) models.
Also shown as
During heating you may also see cF, which means the indoor fan is running slow so it doesn't blow cold air while the coil warms up.
Difficulty
Most people can clear this one at home with simple checks.
Not sure you are reading the code right? See how to read Carrier air conditioner codes.
How to fix Carrier CL / dF
Clean the filters for CL
Turn the unit off, open the front panel and pull out the filters. Wash them with mild soap and water, let them dry completely and refit them.
Wait out dF
Leave the unit alone during defrost; it ends on its own within about 15 minutes. Carrier treats a light frost on the outdoor coil in winter as normal, while a thick coat of ice means something is wrong.
When to call a technician
Get a technician out if the outdoor unit stays coated in ice after defrost cycles, or dF repeats so often the room won't warm up. Don't chip ice off the coil.
Parts linked to CL / dF
These are the parts most often behind this code. Tap one to see what it does and the signs it is failing.
Order parts by your full model number so they fit.
Frequently asked questions
Which Carrier models show the CL / dF code?
Status messages on Carrier 40MHH high-wall ductless units; dF appears on the heat pump (40MHHQ) models.
Can I fix Carrier CL / dF myself?
Usually, yes. Most CL / dF problems clear with simple checks you can do at home. Start with the first step above: clean the filters for cl.
Other Carrier air conditioner codes
- Solid / 1 / 2Status light showing normal operation
- 16Lost communication with the Infinity control
- 25Model plug missing or wrong
- 31 / 84High-pressure switch tripped or locked out
- 32 / 83Low-pressure or discharge temperature trip
- 45Outdoor control board fault
- 46Brown-out: supply voltage too low
- 47No 230-volt power reaching the outdoor unit
- 53 / 55 / 56Outdoor air or coil sensor fault
- 71 / 72 / 81 / 82Compressor thermal cutout or lockout
- 73 / 74Contactor stuck closed or not closing
- E1Ductless indoor and outdoor units not talking
- ECRefrigerant leak detected
- E3 / F5Ductless fan speed out of range
- E4 / E5 / F1 / F2 / F3Ductless temperature sensor open or shorted
- F0 / P1Ductless overcurrent or voltage protection
- P3Too cold outside to heat
- P5Multi-zone mode conflict
Last reviewed 2026-10-22. Codes and steps can vary by model; check your owner's manual.