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Oh ffs. Right instantly I'm thinking of a couple things but it could be a number of components being the problem child. To help you further over the forum could you tell us what the burner is doing, trying to do at point of lockout? A video showing point the burner fails and fails to reestablish would be very helpful.
 
Oh ffs. Right instantly I'm thinking of a couple things but it could be a number of components being the problem child. To help you further over the forum could you tell us what the burner is doing, trying to do at point of lockout? A video showing point the burner fails and fails to reestablish would be very helpful.
What are the things your thinking it could be?
I’ll try get a video next time.
 
I'm thinking MAYBE a sticking pump or bad bearings, although that's just speculation. It could be a number of other things though. A video so I can see and most importantly hear would help massively, although this being intermittent it could be a while before you can catch it on video. You could get lucky in 5 minutes, it might take a lot longer. When these burners lose flame they automatically go through a re ignition cycle before lockout occurs, ideally to get a good idea I could do with a video showing all of it.
 
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quick update, boiler failed to start this morning when other half was getting ready for work but restarted on 1st press of button. Boiler came on at 4:30pm without issue.
 
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Ok. Providing the new capacitor is healthy then I assume this is not the culprit. I'm assuming it's not fuel related as if it were it would usually be more frequent. It could be as I said a few posts above or it could be another electrical fault. It's not helping either of us by being intermittent and starting first push on reset button.
 
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Ok. Providing the new capacitor is healthy then I assume this is not the culprit. I'm assuming it's not fuel related as if it were it would usually be more frequent. It could be as I said a few posts above or it could be another electrical fault. It's not helping either of us by being intermittent and starting first push on reset button.
It’s very frustrating. Not many more electrical components to change.

If it was an electrical fault, could it be electrical fault with the motor? If so can this be tested in any way?

With regards to the pump you mentioned in earlier post can that be checked?
 
The motor is a simple device as you know, a rotor with permanent magnets, primary and auxiliary windings and two sets of bearings. Yes the resistance of motor primary and auxiliary windings can be checked but without knowing what burner it is and finding the correct info either online or phoning technical I couldn't tell you what the readings should be. If these readings were off you could experience similar to a faulty capacitor where the motor could stall.
To check if you have a tight spot on the pump someone would have to isolate fuel and remove pump and components, then by hand spin the shaft to see if there were any tight spots, that would also be the time to spin motor shaft to see if bearings were good and check pump coupling isn't sheared.
However this requires competence and confidence.
The best I can say now is bring on the boiler at programmer (HW or CH) and then go to burner and isolate the rocket switch, then give the burner lots of work to do by switching switch on and off. Turn on and see if ignites, if it does then off and on again until it hopefully fails, by doing this you're effectively bullying it into making a mistake, if it does make note of what happened and most importantly didn't happen.
NOTE these rocker switches are notorious for failing themselves so don't try this too much or too often, the last thing you need is to replace a switch before checking everything else can continue.
 
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I assume you’ve set the burner up. What flue gasses are you getting?
If you’re getting too much air it can cause intermittent ignition problems.
 
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Hi it’s a sterling burner
Failed to start this afternoon. I’m hoping you can view video I took.
As for flue gases it’s running ok according to heating engineer. I have the sheet from when I was serviced, I’ll have look for it.


 
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I hear pre purge and solenoid click, fuel flows and sounds like ignition, then it sounds and looks like fuel stops flowing and burner stops a second before lockout. What parts did you say were changed?
At the moment I would be checking what the pressure does moments before flame stops, you could have a dodgy coupling slipping or the pump drive keys is on it's way out. The capacitor and motor seem fine and to answer one of your previous questions I would check to see if the old capacitor is screwed into motor frame, it looks like theres a collar there but I cant remember off the top of my head.
 
I'd be checking electrode position, once had to fit a burner upside down due to this, don't ask me what difference it should make, but it ran like a train after.
Also at excess air as DaveyHep was alluding to a couple of posts back.

I don't want to argue Si because I know you're competent but have a look and listen to the video. I'd be checking what I said first as its clearly igniting, yes electrodes and air affect these as we all know but the video is telling me more than that.
 
I hear pre purge and solenoid click, fuel flows and sounds like ignition, then it sounds and looks like fuel stops flowing and burner stops a second before lockout. What parts did you say were changed?
At the moment I would be checking what the pressure does moments before flame stops, you could have a dodgy coupling slipping or the pump drive keys is on it's way out. The capacitor and motor seem fine and to answer one of your previous questions I would check to see if the old capacitor is screwed into motor frame, it looks like theres a collar there but I cant remember off the top of my head.
Components changed so far are capacitor, clear hose, fire valve/nrv, photocell, solenoid and ebi transformer. Also DKO control box replaced in 2012 but was doing this prior to this. Boiler was serviced in September.
 
So this has been a problem since 2012?
Yeah pretty much, I’ve been with other half 5 years and we had mainly used immersion heater for hot water and kept pressing reset to get boiler started for heating or used log burner in living room.
 
From what I've seen and heard from video is its igniting, then theres a loss of flame during safety time and it's going to lockout. It could be as Simon above suggested about air it could also be what I said. Have you taken black cover off the front to expose air damper adjuster and made a note of what setting it's on.
 
I'd be checking electrode position, once had to fit a burner upside down due to this, don't ask me what difference it should make, but it ran like a train after.
Also at excess air as DaveyHep was alluding to a couple of posts back.
Boiler sometimes will work ok for 7 days before it suddenly locks out.
[automerge]1580666352[/automerge]
From what I've seen and heard from video is its igniting, then theres a loss of flame during safety time and it's going to lockout. It could be as Simon above suggested about air it could also be what I said. Have you taken black cover off the front to expose air damper adjuster and made a note of what setting it's on.
I’ve taken photo and attached it.
B8C7DF94-7D5A-4BC6-AE5D-4DD95A5ACD55.jpeg
 
I don't want to argue Si because I know you're competent but have a look and listen to the video. I'd be checking what I said first as its clearly igniting, yes electrodes and air affect these as we all know but the video is telling me more than that.

Difficult to tell with TV going full tilt and granddaughter trying to drown the telly out with her tablet. Not a fan of listening to videos for diagnosis.

I did hear fan, good spark but the ignition sounded a bit muffled.

Also good to see that we are not having to wait now to get answers.


Plus the golden rule, just because it's new out the box, doesn't mean the new part is good. Seen a few new parts being faulty.
 
It looks like it's in the right area but without test equipment i couldn't say for sure. So help us further, how often have you been using the immersion and log burner? 8 years is a long time where if you were using the boiler more often the problem will have presented itself by now.
 
It looks like it's in the right area but without test equipment i couldn't say for sure. So help us further, how often have you been using the immersion and log burner? 8 years is a long time where if you were using the boiler more often the problem will have presented itself by now.
the problem with the boiler has always presented it self, it’s just that we’ve made do with it and worked around it.
We thought it had been sorted when we had those parts replaced, it’s mainly winter that we have the issues as using boiler more for heating.

can’t get boiler to start up this evening......
 

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