Problem getting burner to keep firing

[Robert Tyrrell]

ok - I'm on holiday at the moment and I can't get to the boiler to try anything at the moment but this is bugging me so I'd like your opinions on probable causes/remedies.
Just a few hours before I left for my holiday I got called to a breakdown of a Worcester heatslave because it had started to play up with the burner firing, staying on for 9 seconds, and then going to lockout.
I've done all my diagnostics. Changed the nozzle, pump, photocell, and oil line but I still couldn't get it to work for longer than 9 seconds.
Customer said it started to play up about 2 weeks ago and has steadily got worse.
They aren't too worried about it not working at the moment but I'll be going back as soon as I return from my holiday so any advice would be gratefully received

 

[ShaunCorbs]

Heating pump not pumping?

 

[Robert Tyrrell]

Heating pump not pumping?

Ahhh - now there's a thought. Just goes to show what goes out of the window when you're trying to get packed in time to catch a flight eh?
Thanks.
That'll be my first check when I get back to it

 

[mache]

Solenoid on its last legs. ???

 

[quality]

Ive had that before

 

[Chalked]

What pressure were you getting at the pump?

 

[Robert Tyrrell]

Solenoid on its last legs. ???

Forgot to add that to the list but it was a new danfoss pump, and solenoid. The pressure I set was from the MI

 

[SimonG]

Control box.

 

[Gazzt]

What about the capacitor, it should be 3uf or 4uf, if you have a multi multimeter you can test capacitor.
Also if it was a danfoss L 21 or R21 you have to remove the bypass screw as they now come setup for 2 pipe rather than 1 pipe. Just something to check.

 

[SimonG]

Burner wouldnt fire if it was capacitor. Just buzz.