F.68 - Unstable flame signal

What does F.68 mean?

The boiler's flame signal is unstable, which can be caused by various issues related to gas supply, air mixture, or flue gas system.

• Air present in the gas supply.
• Gas flow pressure is too low.
• Incorrect air-to-gas ratio.
• Condensate duct is blocked or there is flue gas recirculation.
• Incorrect gas restrictor or interruption in the ionisation current (cable, electrode).

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

   Ensure the gas supply is free of air (e.g., by operating other gas appliances for a short period) and that gas flow pressure is sufficient.

3. 3

   Check the condensate duct for any blockages and clear if necessary.

4. 4

   Contact customer service. This fault has multiple potential causes related to combustion and gas supply that require expert diagnosis.