Worcestor GreenStar Lockout

[chobson]

Hi all,

I have a Worsector Greenstar Heatslave 18/25 external boiler that randomly goes into lockout, usually about 2/3 times a day. I have had a boiler company out numerous times and they don't seem to be able to fix the problem.
So far they have replaced, Tiger Loop, diverter valve, inline filters, nozzle, photocell, serviced boiler and adjusted electrode gap. I got so fed up with no results from the company and a continued expense I have now decided to try and sort it myself.
First thing I did was buy a new control box, this made no difference so I returned it for a refund. I then went and bought a new pump/coil/solenoid as it was almost the same price to buy the whole assembly rather than just the solenoid and coil. After replacing the pump/solenoid/coil all was good for about 2 weeks and now the exact same problem has started again.
Of course the solenoid/coil could have gone again, I will check with a multimeter when hot and cold, but what else could I check?
Any help would be greatly appreciated!

 

[Terrywookfit]

Check Motor capacitor.

 

[chobson]

Hi Terry, thanks for the reply.
Out of curiosity, what makes you think it is the capacitor?
Just to clarify, once the system goes to lockout and I restart it, the fan runs, relays click, it just fails to fire. Sometimes it will start on first reset, sometimes it might take at least 10 attemps! It is a Bentone burner also.

 

[Burnerman]

Clutching at the odd straw.....did you set the oil delivery pressure after renewing the pump?
Also, make sure the photocell is clean, and directed so that it can see the flame without obstruction.
The spark needs to occur across the electrode tips, and the fan draught then blows the spark into the oil spray......incorrect adjustment can cause the spark to arc onto the blast tube or nozzle instead.
John

 

[chobson]

Admittedly I did not set the pressure as I dont have a gauge, I trusted in the factory settings which from memory is meant to be 10bar. I guess I am having trouble understanding as to why it ran perfectly for a couple of weeks after the pump/coil/solenoid were changed and now its back to its old self!
One other thing is that when it goes into lockout and takes a number of reset retries before if fires is that when it does finally start there is quite a bit of smoke and a strong smell of oil. Exactly the same as what you get when you flood a car with carburettors.

 

[Burnerman]

Usually the pressure required is on a label underneath the top cover somewhere, but this may vary of course on the external type. I would have thought that 10 bar is a bit on the high side but I don't have the data with me.
It sounds like the oil is getting through though, so ignition is the likely culprit.
On awkward so and so's like these, I run the burner on the bench with its own power and kero supply.
Is there any way you can back the burner out of its hole and check for the correct spark, or do you not fancy that?
John

 

[Terrywookfit]

It takes just 30secs to measure the capacitance.

As most other bits have been changed it seems a logical step.
The other "Repair co" must have checked combustion, so lack of starting torque would seem like an obvious check!!

A dodgy EBI could also give problems.

 

[chobson]

Thanks all for your replies! I have before taken the burner out and held the photcell in my hand and restarted the system. I will next check and change the capacitor and EBI as you guys have suggested, not that many parts left to change now!
In response to the company and technicians that have attended this boiler over the year, I reckon the bill would be close to about £600-700 by now. I made sure I was present for the last visit and asked lots of questions. His reply was because it was a random fault not not possible to duplicate then it was too difficult to pin point the problem. Now I do agree this does make it difficult, but he did not check capacitor/coil/solenoid. When I asked him why he commented that you cant tell because the resistance changes with temp, again I agree, but seriously very little effort or thought went into any diagnosis, just a lot of expense. So again thankyou to all your helpful thoughts. I will keep you updated!

 

[boilerdoktor]

op you d have saved a pot load by getting worcester out from the start!! they do a one off fix fee.

following your DIY route with no experience or correct kit for measuring co2,oil pressure etc I imagine you ll be spending a few more quid before its actually fixed

 

[slapper]

You can also buy a complete new burner to match from Heating World of Spares for about £300.00

 

[Boilerman2]

Indeed you can BUT it would still need someone with test equipment to make it work!

 

[Terrywookfit]

Why the fook would you change a burner for a simple fault?

I repair them for a living!

Four King amateurs!