Code 27 — Fan Coil Invalid AC/HP Size

What does 27 mean?

This fault indicates that the Fan Coil unit's control system has detected an incorrect or incompatible Air Conditioner (AC) or Heat Pump (HP) size. This can prevent the system from operating efficiently or at all.

• Fan coil unit mismatched with the outdoor AC or heat pump unit
• Incorrect size setting programmed on the control board
• Faulty control board or sensor
• Installation error

Click steps to track your progress.

1. 1

   Turn off power to the fan coil unit and the outdoor unit at their respective circuit breakers for 30 seconds.

2. 2

   Restore power and allow the system to reinitialize.

3. 3

   Check your thermostat settings to ensure they are appropriate for your system.

4. 4

   If the issue continues, contact a qualified HVAC technician to verify system compatibility and programming.