ecoflam oil burner intermittent fault

[KeviB]

Hi
I have recently been working on an ecoflam burner which heats the cooker part of an Alpha range cooker.
The cooker fires up and gets to temperature and goes through the cycle of firing up to maintain the heat but on occasions when it tries to fire up it locks out.
The filter is clean and the boiler burner is working perfectly which uses the same oil pipe so no restrictions.
New nozzle fitted and the emissions are good for both co2 and co.
Pump pressure is steady 120 psi
The fault occurs when the cooker itself has heated up.
Checked the photo cell this is working and tested the coil which was also working but had cooled down by the time I tested it.
I have changed the coil and cooker warmed up and burner restarted about 11 times before I left.
After about 3 days it started back again and in addition has had blow back on 2 occasions which has opened the doors about an inch
My plan is to go and change the oil pump with solenoid and re check the electrodes and cables Just wandering if someone else has had a similar problem and looking for ideas as to what it could be
.thanks Kev

 

[dcawkwell]

Coil. A frequent problem when hot. Also possible oil pump stem sticking
but go for the coil first.

 

[KeviB]

Changing coil did not resolve the problem have today changed the pump with new solenoid and checked the electrodes again and the cables etc for any damage and all good. Spark looked good and strong
Working well when I left but from the past 2 visits takes a week or so before it starts again?
Thanks for the response and advice