No communication with PCB — Communication fault between display and PCB

What does No communication mean?

The display is unable to communicate with the main Printed Circuit Board (PCB) in the electronics box. This means the boiler cannot receive or send control signals or display information correctly.

• Communication fault between the display and the main PCB.
• Loose or disconnected ribbon cable between the display and PCB.
• Defective display unit or main PCB.

Click steps to track your progress.

1. 1

   Press the fault clearance key on the boiler to attempt a reset of the system.

2. 2

   Check that the display unit is securely seated and connected to the main boiler body.

3. 3

   If the communication fault persists, contact Vaillant Service Solutions for diagnosis and repair of the electronic components.