Oil burner locks out after running for a few minutes

[oilman]

Oilman! Is there no way the coil can be tested in situ.

I do it all the time. Wait till flame stops, whip connector off coil and measure coil resistance. But you've only got a few seconds.

I certainly wouldn't run it on extension lead without control box. Insurance company won't want to know.

 

[Terrywookfit]

Test the resistance of the coil when in an operative and inoperative state.
It will probably be o/c when inoperative.

 

[DickM]

Wow, quite a flurry of activity over the past few hours!...

I'll definitely try testing the resistance of the coil tonight, but I've stuck my neck out and order a replacement anyway. If it turns out to be the pump, at least I'll have a spare coil if it fails later in life.

Just an aside - I can't quite see how the coil is retained on top of the valve. It looks like there's a small brass plate on top, but on the Sterling burner, it sits below the air intake, so I can't see the top of the coil. Does anyone know if the coil can be removed without first taking the intake moulding off the side of the burner?

Cheers, DickM

 

[MANDATE]

Terry! Don't quite follow your response. Hope you don't mean to test for resistance while the coil is operating, which would be in an operative state or a state of operation.

 

[oilman]

Just an aside - I can't quite see how the coil is retained on top of the valve. It looks like there's a small brass plate on top, but on the Sterling burner, it sits below the air intake, so I can't see the top of the coil. Does anyone know if the coil can be removed without first taking the intake moulding off the side of the burner?

Life's hard sometimes, you have to take two whole screws out to remove the air intake cover.

 

[Terrywookfit]

Terry! Don't quite follow your response. Hope you don't mean to test for resistance while the coil is operating, which would be in an operative state or a state of operation.

I assumed that any one who knows enough to check resistances, would also know not to try it with a voltage applied.

Which would be difficult in any case!

 

[DickM]

OK, so here's the end of the story... I hope.

I tested the resistance of the coil just after the burner had shut down, and (just as predicted) it was open circuit.

Had to wait a while for a replacement coil ('overnight' delivery by FedEx took three days!) but it was only a five minute job to fit it, and everything is working fine and dandy now!

Many thanks to all who took the time to contribute to this thread. I hope I'll be able to contribute something in return to the DIYnot forums sometime in the future.

Thanks,
DickM

 

[stumpydick]

gremlin 16 got it right about 15 posts earlier,

 

[andysterling]

I know it's an old thread, but just wanted to sign up to say thanks to the advice/outcome in this thread, my boiler is now working again!!
Being without heating over Christmas was no fun and i resorted to fixing it myself because it was really hard to get someone to come out!

 

[Nathan Stowe]

Good morning,

This was a really Interesting read.... I am having the exact same problems with my sterling oil boiler runs between 4-7 minutes. I have changed the burner nozzle, control box, photo cell. And also cleaned out the oil pump filter. These have all made no difference.
I have now found this website, and wondering if I should change out the solinoid, itt appears to bbee old as the new one has a different model number.

 

[BoilerBob]

There’s a thing called the three suspects coil, photo cell and capacitor.they can cause a heap of grief, I’d try the coil if it not that then you need to go into fault finding a bit more. Bob

 

[Nathan Stowe]

Hi Bob,
As you are probably aware a novice to this, but when you say coil, you mean the one that sits on the oil pump? And what part is the capacitor?
Thanks again for the reply

 

[Terrywookfit]

Hi Bob,
As you are probably aware a novice to this, but when you say coil, you mean the one that sits on the oil pump? And what part is the capacitor?
Thanks again for the reply

Yes on the oil pump.
BFP solenoid coil.

 

[BoilerBob]

The capacitor is fixed to the motor. Bob

 

[Nathan Stowe]

Brilliant thanks, out of interest could the motor capacitor also cause the boiler to cut out, just thinking should I fetch one at the same time???