F.78 — No communication to main board (display connection error)

What does F.78 mean?

There is a communication error between the display and the main board of the boiler. This prevents proper operation and display of information.

• Connection error display main board.
• Loose or damaged cable between display and main board.

Click steps to track your progress.

1. 1

   Power off the boiler at the mains, wait 30 seconds, then power it back on.

2. 2

   Ensure the display panel is securely seated (if accessible) and all connections seem firm.

3. 3

   If the error persists, contact a qualified service technician to inspect the internal wiring and board connections.