Oil Boiler burner problem

[SJW48]

Hi

I have a Worcester oil heatslave 26/32 with a sterling 40 burner. The burner keeps locking out. The oil pump is intermittently pumping oil to the nozzel. I have replaced the pump, photcell, nozzel and tried a new control box and still the problem exists. When the burner fails to ingite there is a electical burning smell coming from somewhere on the burner assy, but I can't pinpoint where. If I switch the power on and off a few time before it locks out I can get it to light up. It looks like a fuel problem but Ive drawn a blank, any suggestions would be appreciated. Thanks for looking.

 

[crockett]

The electrical burning smell could be due to the transformer being over worked, and another reason for the non firing / lockout may be due to the solenoid coil failing, as this seems to be one of the few things you haven't changed

 

[Burnerman]

Certainly I agree with the comments above - but I'd also like to rule out the motor performance, i.e whether its starting every time, and reaching its required RPM.
John

 

[spraggo]

If you continually switch the boiler of and on before the lockout you will cause the ignition transformer to overheat and burn out as they should only work intermittently with at least a gap of 1 minute intervals, I suspect that this is making it smell. Have you checked that oil is flowing freely from the tank to the oil pump? as the indications are that the burner is starved of oil.

 

[SJW48]

I have check the oil supply and thats fine

 

[wiss]

At exactly what point is the burner going to lock out? is it on start up, on fire up, once running etc.........

 

[SJW48]

Most of the time it won't fire up because fuel is not being pumped to the nozzel, then it locks out.

 

[spraggo]

I have check the oil supply and thats fine

If as you say the oil feed is OK it would appear that you have water in the oil line, or the air inlet shutter is opened to much and causing the flame to blow off of the nozzle

 

[wiss]

Ok, You said you replaced the oil pump so you will have a new solinoid too, have you checked you are getting 240v to the solinoid coil?? do you hear a 'click' when solinoid energized

 

[spraggo]

when you changed the oil pump did you check that the dog (the bit that joins the oil pump shaft to the motor shaft) was OK and not worn to cause it to slip on the oil shaft.

 

[wiss]

has fuel pressure been checked??? this may offer some answers.

 

[SJW48]

Hi, Thankyou for all your suggestions, I have found the problem, it was broken insulation on one of the Ht leads. Replaced them and its working fine now.

 

[Boilerman2]

A Service Engineer would have Serviced your boiler set up combustion with instruments and replaced the ignition leads for about £80!!

How mauch have you paid? (Oil Pump, Control Box, Photocell Etc)

 

[SJW48]

I am not stupid! I couldn't get hold of a local engineer quickly and its been bloody freezing here the last couple of nights. I took the control box back for a refund and the other bits came to £81.94 and I know they will be ok for a while. Heating only off for one night, happy days. I came on this forum for some contructive advise, which I received, not to be told the obvious with a load of smiley faces,thankyou.