F1 — Maximum flue gas temperature exceeded (230ºF / 110ºC)

What does F1 mean?

The burner is in a fault mode because the flue gas temperature has exceeded its maximum limit of 230°F (110°C), indicating an overheating condition.

• Low heating system fill level
• Air in the heating system
• Malfunctioning circulation pump
• Faulty boiler water temperature sensor or cable

Click steps to track your progress.

1. 1

   Press the reset button 'R' on the boiler after the system has cooled down.

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, boiler water temperature sensor, and its cable.