It is indeed a BFP21L3 pump. I have ordered a new pump coil and that should hopefully do the trick. I have learnt a bit more about the workings my boiler and hopefully saved a few quid in the process ;)
Thanks for your help and advice.
Is there any way to test the solenoid or pump or motor or photocell rather than just changing parts? I have a fuel pressure gauge, but will need a suitable fitting to enable it to go between the pump and the burner.
I have a 30ish year old Myson Velaire Oil fired boiler locking out. It runs for 5-30 minutes - sometimes even less if I reset it shortly after it locks out, runs for longer end of the scale if I leave it for 30+ minutes. I can hear the fan running for 10-20 second after I hear it stop burning...