F.77 - Flue non-return flap or condensate pump fault

What does F.77 mean?

There is no response from the flue non-return flap, or the condensate pump is defective, both of which are crucial for safe operation.

• No response from the flue non-return flap.
• The condensate pump is defective.

Click steps to track your progress.

1. 1

   Press the reset button on the boiler display up to three times to try and clear the fault.

2. 2

   Check if the condensate pump is running correctly and that its discharge pipe is not blocked. Clear any blockages if found.

3. 3

   Contact customer service. This fault indicates an issue with the flue non-return flap or a defective condensate pump, requiring professional diagnosis.