Search my own database of fault, diagnostic and status codes to aid in fault identification.
Applies to 200 series
Applies to 100-W
On the 100-W, this could be dip switch S2 is set to "on" when it should be off.
This is relevant to the 300 series
Most likely a PCB in this case
Flame detected before ignition start, check ionisation.
Usually after burner ignition, flame not detected, likely condensate, electrodes or ionisation, possibly gas valve.
Signals are not being transcribed properly by the unit, if there are a lot of electronics nearby, temporarily disable them, otherwise it's a new PCB
On the 200 series, this could also be that a flame has been detected after burner shut down.
