F.65 — Electronic temperature fault

What does F.65 mean?

The boiler's electronic components have detected an abnormal temperature, possibly due to overheating from external factors or an internal component failure.

• Main electronics board is overheating due to external influences (e.g., poor ventilation, external heat source).
• Main electronics board itself is defective.

Click steps to track your progress.

1. 1

   Ensure that the area around the boiler is clear and well-ventilated, without obstructions blocking air vents.

2. 2

   Press the fault clearance key on the boiler to reset it.

3. 3

   If the fault persists, contact Vaillant Service Solutions for further investigation.