F3 — Flame signal already present at burner start

What does F3 mean?

The burner is in a fault mode because a flame signal was detected before the burner officially started, which is a safety concern.

• Faulty ionization electrode or its connecting cable
• Electrical interference

Click steps to track your progress.

1. 1

   Press the reset button 'R' on the boiler.

2. 2

   Ensure the area around the boiler is free from strong electrical interference.

3. 3

   Contact a qualified heating technician to check the ionization electrode and its connecting cable.