F.28 the fault code on a valliant boiler. ? Can anyone tell me what this st?

This means that the automatic ignition was not successful within 10 seconds (when restarting to provide hot water for taps or heating). The unit switches to a Lock Out state. To return to normal operation you need to press the reset button, this has a flame symbol on it on my boiler and is located to the left of the "i" (information) button.

Peter
February 2009