Sabre/Vokera 24-28 HE combi. Only gets to ignition when inner case opened.

[casaco]

This boiler is driving me nuts, I have spent hours trying to sort it, cost me a fortune on the phone to vokera tech who to be honest seem to be quite hostile at times, (anyone else feel that way?)
The problem is everything works fine, pump runs, fan runs, APS works but no spark, open the combustion front, hey presto spark ignition, close combustion front no spark, fan and pump still running.
I have removed the fan and cleaned venturis, changed the APS, still the same, no blockage in the flue, fan running full strength. The tenant is behind with the rent so the landlord isn't interested, would like to get the heating back on for Christmas, she has a couple of young kids and hasn't had any heating or hot water for 6 months.
Has anyone any idea, am I missing the obvious?

 

[tipintim]

Air presure switch

 

[casaco]

No, fitted anew one, same result.

 

[Mbear]

Dirty fan Venturi. Aps tut tut tut

Always clean the Venturi first

 

[Mbear]

Sorry I misread ur post. My next port of call would be remove the flue restrictor. That should sort it mate

 

[tamz]

^^ if it is fitted

 

[Mbear]

Have the fan impeller blades been washed/cleaned aswell?

 

[casaco]

Took both venturis out, emery clothed them, spotless, now you can see why I am frustrated, the fan is really powerful and you can hear the APS click in, but no ignition til you open front of combustion box, Vokera tell me that it is definitely air flow problem, I have stripped it down 3 times and checked everything, but still can't get to ignition stage til front cover opened.

 

[casaco]

Not a mark on them, still look brand new, don't think she has used the boiler much since it was installed, that's what I can't understand, it looks as though it was installed yesterday, but it wasn't of course.

 

[Mbear]

There's only a few things left mate....

Remove flue restrictor, clean fan blades, worst case scenario is replace fan or flue

 

[casaco]

Yes thats a good idea, but is that allowed, not to manufacturers instructions, I tried to get the flue elbow off but there isn't enough leeway without knocing the plaster off round the flue.

 

[tamz]

Might have been the wrong restrictor fitted since new. It wouldn't bother me to knock a bit plaster off to get the bend off.

 

[Mbear]

Yes thats a good idea, but is that allowed, not to manufacturers instructions, I tried to get the flue elbow off but there isn't enough leeway without knocing the plaster off round the flue.

I'm 99% confident it will fix it. As said above the installer may have fitted the wrong size originally. It won't don't it any harm anyway

 

[GQuigley67]

customer will want boiler fixed and wont care about the seal around it, just explain this to customer it will have to be taken out and resealed if you want your boiler fixed, bit of decorators caulk to seal it again and then customer can paint over.

 

[marleyco]

Had same problem with vokera, I sorted it by cleaning the heat exchanger with brushes. ALso air in was clear.

 

[casaco]

Thanks to everyone who replied, I will go back this week and remove the flue restrictor and check heat exchanger is clear, the boiler has been running for a couple of years without any problem, but just won't fire up now. Got to be something simple. This is the first boiler I haven't been able to fix.

 

[marleyco]

Hi casaco, when I had the problem on vokera. British gas had been out twice to it, they must have checked all the things others have suggested which left me with one possible solution, which as I mentioned was to clean it. Hope it goes ok for you

 

[casaco]

Thanks marleyco, not a lot of options left are there, will have another go this week.

 

[ultimategas]

Did this issue get sorted as I've had the same today done all the above no restrictor either ???

 

[Dotty]

Moved to private forum. Then I wrapped my arms round my knees and leaned forward........



........ Cos that's how I roll...........

 

[bigads28]

To see if your fan is fast enough / producing enough pressure through the venturi, attach a gauge to the fan an see what pressure is produced.

Also don't rely on your ear for the click, but check with a multimeter to confirm power.

If the fan blades are dirty I don't like washing them, use one of the air dusters outside lol!

 

[kris]

Nice one adam , ive had that b4 thinking you coiuld here the aps making loud n clear so lookin for fault elsewhere but when i checked voltage it was no where near enough goin back to board,

 

[mfgs]

99% of the time, its the venturi that needs cleaning on these.

 

[arran197]

I had a Ferroli doing the same. I had to fit new venturis in the end, cleaning them didn't solve it. I put a new fan on too because I broke the neutral connection off, but the old one really needed cleaning, so check that too. The blades were caked in dust.