EC Error Code

Here is some information to solve the issue.

EC error code, notifies you that your unit has a restriction in the pressure or that it is simply low on R410A refrigerant. In this case, you will have to contact a certified HVAC technician to verify the pressure first, and if the pressure is accurate according to the gray sticker on the side of your condenser, then your system must be low on refrigerant.

If you extended your line set, please make sure that the factory refrigerant charge is sufficient to cover this distance, if not you will have to add some refrigerant.