The error code "3 x blue blinks" is namely caused by PCU overheating, but is also triggered by any unexpected microcontroller halt. To solve this error, follow the instructions below.
1. Reboot the PCU by switching the fuses off-on.
If this helps and the 3 x blue blinks disappear, there's no need to do more. If the problem recurs 2-3 times in a short timeframe, it is advised to replace the PCU.
2. Renew the radio connection between the sensor unit and the PCU
See instructions "Manual Adjustment mode 2 (Manual setup of the wireless connection)" or follow the same steps in the Installation manual.
If this helps and the 3 x blue blinks disappear, there's no need to do more.
If the problems persists, it is advised to replace the PCU