Error Code: F1 - Communication Fault

The error code ' F1' means the indoor unit PCB and outdoor unit PCB cannot communicate with each other. 

To fix the problem you can do the following: 

  • Check all connections are clean and tight. Corrosion on connections can cause this error, use light abrasive paper to clean each one. 
  • Check the connections are connected to the correct place, wiring diagrams are printed inside the indoor unit and in the outdoor unit PCB case. 
  • Check for any breaks in the black communication wire, if chock blocks or rotary isolators are used then check the connections are properly connected and the isolator is turned on 

After checking everything - all the connections are clean, tight and correct - then that means there is a problem with the PCB. You'll need to replace both the indoor and outdoor PCB. You can do this by contacting us via email at or call us at 0370 3344 556. 


  • 44 Users Found This Useful
Was this answer helpful?

Related Articles

Error Code: F2/F3 - Internal Temperature Sensor Fault

Both error codes signify that there's a problem with the internal sensor. The difference between...

Error Code: F4 - Internal Fan Fault

The error code 'F4' is indicating either a fault with the indoor fan motor or indoor PCB. To...

Error Code: F6/F7/F9 - External Temperature Sensor Fault

All 3 error codes means there is something wrong with the sensors - the difference between the...

Error Code: FC - Compressor Drive Fault

This error is signifying a fault between the compressor and external PCB.  To fix the error code...

Error Code: F5 - IPM Module Fault ( Intelligent Power Module )

The IPM module is the inverter module which controls the speed of the compressor and the outdoor...