HRM Wallstar Oil Boiler - Advice please

[Simonvr46]

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?

 

[SJB060685]

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.

 

[DaveyHep]

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.

 

[Simonvr46]

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.

 

[SJB060685]

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.

 

[SimonG]

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.

 

[SJB060685]

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.

 

[Simonvr46]

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.

 

[SJB060685]

So this has been a problem since 2012?

 

[Simonvr46]

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.