F4 / F0 / EC 51 - Error Code Diagnostic

Modified on Wed, 25 Sep at 11:50 AM

If the error codes F4 or EC 51 appear on your indoor unit, this indicates an outdoor EEPROM parameter error or a communication error between the outdoor main chip and the compressor drive chip.


Replacing the outdoor PCB board is required to fix the problem


To order a replacement part or to get further assistance in diagnosing your unit, please contact one of our support representatives by submitting a ticket using the link below.


Submit a Ticket


*Please note these procedures must be performed by a certified HVAC contractor.

Was this article helpful?

That’s Great!

Thank you for your feedback

Sorry! We couldn't be helpful

Thank you for your feedback

Let us know how can we improve this article!

Select at least one of the reasons
CAPTCHA verification is required.

Feedback sent

We appreciate your effort and will try to fix the article