Help - oil fired boiler playing up

[jonba]

Hello all,
Can anyone help with some ideas to sort a camray5 oil fired boiler out?Cant get the thing to run, so far have checked oil pressure, air shutter,photo cell, new pump, new oil filter, new jet and checked pipes for blockages - all o.k. Boiler just goes through the motions but doesn't fire. Have even swapped the whole boiler for the same unit and connected this up, this fired up straight away! Because of this I thought the control box on the boiler may have had it, so swapped these to see if that would work...nothing! So any help would be greatly received.

 

[oilman]

solenoid and its coil?

pump coupling?

 

[jonba]

New solenoid and new pump.Have cracked return pipe and oil is present.To work out why the donor unit worked I swapped out the electrical bits and bobs one by one to eliminate the faulty part.Still not firing up.

 

[MANDATE]

I'm no expert! but I'd concentrate on (a) the spark at electrode and (b) the oil delivered from the nozzle.
What I did when replacing parts was (a) test the spark at electrode with transformer on the garage bench, and replace nozzle and ensure no blockage.
Fit nozzle assembley to burner.
Leave Control box unwired and wire up the 'transformer', 'motor/pump' and the 'solinoid' each to separate sockets in a 'switched extension lead.
You can then try each in turn for operation, then motor/pump followed by solinoid and in my case I could see the oil spray from nozzle.
When I was happy everything worked, it was (a) transformer on then (b) motor/pump on then (c) solinoid on and boiler flashes up then (d) transformer off.
I ran boiler for a few minutes then repeated the operation a couple of times.
I was then happy any problem encountered had to be control box/photo cell related. Everything wired back to control box and boiler re lighted.

 

[oilman]

Difficult as it's a Riello burner.

The motor should be giving 50V on the white wire when running, this powers the control box.

 

[jonba]

Many thanks for the help so far.Will have a go monday and keep you posted on what happens....

 

[jonba]

All sorted now. Intermittent fault with the brand new pump.
, solenoid valve sticking.Thanks for all the advice what a head banger!!!