Fault F1 (Detailed 135) — Burner fault: flue gas temperature exceeded limit

What does F1 mean?

The burner is in fault mode because the maximum flue gas temperature limit of 230°F (110°C) has been exceeded. This is a critical safety shutdown indicating potential overheating or restricted exhaust.

• Maximum flue gas temperature exceeded 230°F (110°C) limit

Click steps to track your progress.

1. 1

   Check the heating system fill level and add water if it is low.

2. 2

   Bleed air from the heating system to remove any trapped air.

3. 3

   Check the circulation pump to ensure it is operating correctly.

4. 4

   Check the boiler water temperature sensor and its cable for proper function and connection.

5. 5

   Allow the vent system to cool down completely before pressing the reset button R on your boiler.