F2 — Fixed high limit switch open (activated)

What does F2 mean?

The burner is in a fault mode because the fixed high limit switch has opened (activated), indicating an overheating safety shutdown.

• Low heating system fill level
• Air in the heating system
• Malfunctioning circulation pump
• Faulty fixed high limit switch or its connecting cables

Click steps to track your progress.

1. 1

   Press the reset button 'R' on the boiler.

2. 2

   Check the heating system's fill level and ensure it is within the recommended range.

3. 3

   Bleed air from the heating system and radiators.

4. 4

   Contact a qualified heating technician to check the circulation pump, and inspect the fixed high limit switch and its connecting cables.