potterton prima 40 at my witts end

[osteriaantica]

Hi I have the above boiler which will not ignite . I have changed the air pressure switch , ebc and had the remedial flue kit , and only when i disconnect the white tube off the air pressure switch and suck on it does it light and remain lit . The air pressure switch is only connected by the red tube and the boiler is running fine . Will this damage anything ? .
Any help guys
Thanks
Otis

 

[powell30]

venturi......try cleaning it out.....or check flue for blockages

 

[corgiman]

Check the restrictor to

 

[osteriaantica]

Thanks for the prompt replies . is the venturi the spinning fan inlet . as far as the restrictor is concerned it is very tight but i can see through it and i've claened it through best i can , is its diameter crucial ? .
Sorry guys one more thing ,i'm running the boiler at the moment with the white tube disconnected fron the air pressure switch , is this dangerous ?
Thanks
Otis

 

[osteriaantica]

Hello again
Well i've changed the restrictor now and still nothing any other suggestions most welcome . Once again thanks guys
Otis

 

[weargas]

The venturi are the parts inside the flue that the red and white tubes connect to. Any restriction in the venturi will result in not enough air pressure to move the air pressure switch.
Is there a garlic bread in this for the one who gives you the right diagnosis?

 

[osteriaantica]

Hi Weargas
Yes the venturi is clear i've had the top of the fan off and all is clear.
Someone else is coming out today with some new ideas and yes at least a garlic bread for the first person to diagnose the problem .
Dont think there's many more bits to change is there ?
Getting colder
Otis

 

[Diyisfun]

Surprised Ive not seen the word & the word is C***i

 

[osteriaantica]

1st engineer changed all parts bar the flue
2nd engineer corgi reg came and said your flue is damaged so 60 quid to him. remedial kit was sought and replaced , when i informed him it still didnt work he said " i'll ring you later , did he f@ck .
So 350 pounds later awaiting 3rd engineer .
Let you know what happens
Shivering
Otis

 

[weargas]

Has anyone looked at the fan blades to make sure they aren't crudded up? If they are the fan would spin at the right speed but not produce enough air pressure. Be careful not to disturb any clips on the fan blades they're there to balance it (a bit like a car wheel). If the fan goes out of balance it'll wear the bearings quicker and shorten it's life.
I've also changed my order from a garlic bread to home made tagliatelle with pancetta and a creamy pesto sauce.

 

[osteriaantica]

There's a 3 course meal on offer now .
3rd engineer here now and guess what nothing .
Boiler runs with white hose disconnected he says must be a faulty pressure switch i've had 2 .Fan and venturi are fine .
Any new ideas , dont tell me a new boiler .
getting colder
Otis

 

[weargas]

Has anyone cleaned down through the heat exchanger fins to make sure there's an adequate passage for the fumes to pass? If the fan can't suck through it fast enough it would affect the differential air pressure. That would also tie in with the "works without one pipe connected theory"
It's a pig of a job and on-one will be keen to do it (unless you get a fitter who loves solving problems) because stripping the fan and flue hood off is sometimes so awkward and the flue hood seal can get damaged.
Instead of a 3 course can I have it the Italian way? 5 or 6 smaller plates spaced out over a number of hours.

 

[osteriaantica]

Hi Weargas
Many thanks for the prompt reply . 3rd engineer still on site , on the phone to potterton . This new theory sounds messy and had i known before i would have gone the new boiler route but i'm in for 350+ already . I'm gonna sugest this to him i'l be right back .
Choose your 6 courses . at osteria.co.uk . At least its warm there
Frozen
Otis

 

[osteriaantica]

Engineer assures me its not the fins on the heat exchanger he seems to think it could be faulty air pressure switch AGAIN .
Totally f@cked off now
Otis

 

[TheMrX]

Check my post here. //www.diynot.com/forums/viewtopic.php?t=156608

Different problem but also a potterton.

Their own engineers guarantee a fix for £299 and everything is then covered for a year. Shame you didnt know before laying out the £350 originally. I was lucky, my engineer tipped me off.