Rayburn 480k lock out problems

[Mike2007]

I have a Rayburn 480k(oil fired, ecoflam burners). It keeps locking out on the burners as well as the boiler overheat stat. I've changed the boiler control stat, the cooker control stat and serviced it.
The burner has the new digital control boxes on.
Why would it lock out on burner control boxes and the boiler stat. Thinking maybe pump over run stat isn't running?

 

[oilhead]

The two problems are not connected. Overheat is down to lack of circulation. Could be the pump overrun is not working. A simple electrical test would prove that. If it is operating even on the cooker side, then pump overrun is favourite. Also check the circulation pump.
Are you getting burner lockout on both burners? If so, you must have a fuel supply problem. Check all filters, and also oil pump pressure.

 

[Mike2007]

Thanks, I will try these out.

 

[Robert Hindle]

I had an intermittent lockout on my 480kb rayburn. The fault gradually got worse over 3-months. I changed the boiler stats check pump pressure air flow, nozzles ect I checked the flame sensor photo cell remotely from the assembly by using a flame and it appeared to switch ok, At this point I was getting desperate for a solutions I changed over the photo cell sensor from the cooker one and there was the problem. The photo cell must have been right on the edge of switching sometimes working some times not. Iv'e had my Rayburn since 1997 and serviced it myself for all these years with very few faults. If your Rayburn is 20 years old like mine I'd invest in a photocell sensor for the boiler,( about £20) the cooker side will probably be ok as it's not used as much.