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Carrier Air Conditioner EC Error Code
Refrigerant leak detected on Carrier air conditioners.
CarrierAll Carrier air conditioner codes
In cooling, the indoor coil should get cold soon after the compressor starts. The board starts checking the coil sensor 5 minutes in, and if the coil fails to cool down three times, the unit shows EC and shuts down. Carrier lists a leak or blockage in the refrigerant system, a bad coil sensor or a faulty indoor board.
Compatible models
Carrier 40MAQ and 40MHH high-wall ductless units in cooling mode.
Also shown as
The check only runs in cooling mode. On the 40MAQ the operation lamp shows it as seven blinks.
Difficulty
Try the basic checks, but the usual fix is a technician's job.
Not sure you are reading the code right? See how to read Carrier air conditioner codes.
How to fix Carrier EC
Look and listen
Note whether you see ice on the indoor coil or the copper lines, or hear hissing near the line set. Carrier links both to a refrigerant leak.
Shut the system off
Turn it off with the remote and leave it off rather than restarting it in cooling.
When to call a technician
Refrigerant doesn't get used up, so a low charge means a leak. Finding and repairing it is work for an EPA-certified HVAC technician; skip the DIY recharge cans.
Parts linked to EC
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 EC code?
Carrier 40MAQ and 40MHH high-wall ductless units in cooling mode.
Can I fix Carrier EC myself?
Only the basic checks. You can safely try the steps above, but EC usually points to a part or fault that needs a technician.
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
- 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
- CL / dFFilter reminder or defrost in progress
Last reviewed 2026-10-22. Codes and steps can vary by model; check your owner's manual.