Any oil boiler techies on?

I got a Worcester Greenstar 12/18 kw oil boiler.

It won't fire up, if I press the big red button the fan comes on and I get a spark. Some oil comes through - it ignites and cuts out straight away.

Any ideas please?

Thanks in advance

Mark

No expert, I have a similar boiler, once (after it had been serviced) I had to reset it, If I recall correctly there is a reset button behind the front cover - slightly hidden by the front controls panel?

Yep that's the big red button

Bit cold to be without, on balanced flue boilers you have a little pipes that respond to air pressure in the exit of the exhaust, if these get sooted up or a tiny bit of debris then the boiler believes the vent is blocked, fires and cuts out immediately.

Is the exhaust all clean and clear?

inside the head you will find a "magic eye" it senses the flame, if its dirty it will not sense flame and cut the oil off. Look for a small cable going into the burner head, normally they are a loose fit, pull it out clean it and try again, if it fails to light you have a faulty sensor. Have you had it serviced recently ?

Ok not a balanced flue so I don't think it's that.

I checked the magic eye and it is very clean.

I guess it might be that then, is there any way to check it?

Was serviced last year. Is the magic eye a service item?

Cheers Mark

is your greenstar the condensing version? if so blocked or dirty condensate will cut it off as well. have you checked your oil level?

Yep condensing. Condensate pipe clear.

Oil tank nearly full

No air in system tiger loop fitted - I checked the bleed screw anyway

The photocell should have 0.5-20k ohm resistance in bright light, >500k ohm in the dark, you should be able to get one from most plumbing suppliers from stock.

Dave

ok measuring it now

if I'm reading the meter correctly: in bright light it's about 0.3k ohm in the dark its off the scale

I had similar problem it was sooted up it seems that condensing boilers need frequent servicing. Remember your guarantee is for 7 years with bosche
Cheers

bosch seven year warranty is subject to the boiler being serviced yearly. so many folk get caught out by that. doesnt have to be worcester that services it, as long as oftec number or gas safe number is put in the book

In true locost fashion, the boiler is second hand off ebay so no warranty.....

I'm not saying this is the right thing to do,BUT, put the boiler in run, shine a bright torch into the magic eye, if it stays lit, OK. Then quickly remove the torch and see if it cuts out. If it does your sensor is OK. Sometimes the flame pattern is interrupted by dirt and the sensor cant see it, but that is extreme.

Buying a new magic eye today will try this evening......

The photocell works a solenoid on the pump and these used to fail regularly on mine giving the symptoms you describe, trace the cable back from the photocell to find it. Once you find the part number it can be replaced easily.

Dmac

Thanks all.

Eventually I worked out that the oil wasn't coming through as well as it should.

I stripped the pump down and cleaned /blew out with compressed air and it all works perfectly now.

Thanks for all the suggestions

Radiators toasty warm again