HRM Wallstar Oil Boiler - Advice please

[Simonvr46]

A capacitor is basic knowledge and always one of the first things to consider/check when experiencing your issue.

I work in mechanical engineering and have a basic understanding of electrics, hence reason off checking/replacing capacitor also that it’s a cheap (consumable) part to replace.
Our heating engineer has never mentioned or tested the capacitor.

Boiler still working, haven’t had to take cover off since fitted capacitor. So I’m ruling the air bubble out as the cause of lockouts.

 

[SJB060685]

I work in mechanical engineering and have a basic understanding of electrics, hence reason off checking/replacing capacitor also that it’s a cheap (consumable) part to replace.
Our heating engineer has never mentioned or tested the capacitor.

Boiler still working, haven’t had to take cover off since fitted capacitor. So I’m ruling the air bubble out as the cause of lockouts.

As you were told by technical it's common to find an air bubble in these hoses, as long as its static and not impeding oil flow then you never have to worry. Yes one could fit a tigerloop or any other deaerator if they felt compelled but I was under the impression this would void any warranty supplied with the HRM boilers anyway.
With regards to the capacitor if you have a background in mechanical engineering then theres really no need for my to give you a run down on how it works and like you said they're a few quid, so easily justifiable.
What worries me about your current engineer (or ex) is this is day one stuff. Usually when a capacitor is on it's way out you can tell on initial burner start up. Although individual electron flow is minuscule in speed the affects of electricity are almost instant and if you had a faulty capacitor when theres a demand for heat the motor would lag for a split second before ramping up, whereas a healthy capacitor it would spin with no latency. Know this and when you're servicing a boiler you should be picking up on it.
For future reference I was always told to replace a capacitor 70% and below original microfarad rating, ie, if it's a 5uF capacitor then replace if its 3.5 and lower.

 

[Simonvr46]

Thank you for your reply.
You guys have been really helpful in confirming my diagnosis of our boiler.

just a case of waiting and hoping it continues starting up when a demand for heating is required.
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Boiler came on at 7am until 8am for the other half getting ready for work. I’ve just gone to put heating back on and boiler has locked out..... 1st time in a week it’s done it. Started up on 1st press of reset button.

 

[SJB060685]

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.

 

[Simonvr46]

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.

 

[SJB060685]

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.

 

[Simonvr46]

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.

 

[SJB060685]

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.