Screen of the sauna controller is blank

In most cases, this happens when the cables of the sauna controller are not connected correctly. Only a certified electrician may connect the cables. Check the following to detect the reason of the fault:

• Are all cables connected to the main module in compliance with the diagram presented in the installation manual of UKU sauna control system? Manual: HUUM UKU Manual US
• Has a cable detached from the controller?