F35 Fault — Air/flue gas duct restriction or blockage

What does F35 mean?

A fault has been detected in the air/flue gas duct, indicating a restriction or blockage that prevents proper air supply for combustion or discharge of flue gas.

• Restriction or blockage in the air/flue pipe caused by obstructions or damage
• Air/flue pipe not installed in accordance with recognised rules
• Flue run restrictions
• Flue seals issue
• Airways of heat exchanger unclean

Click steps to track your progress.

1. 1

   Check the entire air/flue pipe for any obstructions, damage, or improper design.

2. 2

   Ensure the air/flue pipe is installed according to recognized rules.

3. 3

   Clear any detected faults in the product and restart it.

4. 4

   Check the flue run for restrictions and inspect flue seals.

5. 5

   Check the airways of the heat exchanger and clean the burner if necessary (requires specialist tools).