anyone here corgi registered? - boiler advice req.
anyone here corgi registered? - boiler advice req.
Author
Discussion

shirt

Original Poster:

25,078 posts

225 months

Thursday 6th January 2011
quotequote all
i have an issue with my boiler getting up to temp on the DHW then cutting out. the fault lights suggest the air presure switch is faulty but i removed it and brought it to work yesterday where our control engineer tested it and said it was fine.

i refitted it last night and also checked the air pressure from the fan venturi using the manometer he gave me. this was -1 to -2 mbar [gauge doesnt go down to decimals] and the switch operates on the vacuum side only [i.e. not the differential pressure]. switch is set at 1.38mbar.

anyway, with me sucking on the tube i got the boiler to fire first time. then i checked the air pressure - all good - and refitted everything. still fine, heating on, ran bath, all was well. then about an hour later i get the same issue.

water heat up, kicks off, wait a minute or so, then repeat. CH seems to do its own thing, coming on intermittently.

now, i realise i am not qualified to work on the gas side of things but i can remove and fit new parts. however, noone of the DIY forums i've asked on will give me any advice on an open forum as to what to check and look for in diagnosing the fault.

i intend to go through the air tubing from the fan etc. and look for blockages and check the connections to the switch. other than that i'm stumped.

would anyone mind giving me a brief list of things to check [i have a multimeter and the manometer and re-wired/replumbed the house so am competent]. either her or via PM? i would be most grateful as i feel its wasting someone's time to be called out to quote on a job i'd only pay for as a last resort.

cheers.
phil.

Ferg

15,242 posts

281 months

Thursday 6th January 2011
quotequote all
Just scanned your post. Not enough on the airswitch? Spiders webbing in the venturi? I'll concentrate harder later.

shirt

Original Poster:

25,078 posts

225 months

Thursday 6th January 2011
quotequote all
pretty much yeah. removed and replaced = worked for a bit but now not enough pressure again. just after what to check other than blockages in the tubing and venturi.

Ricky_M

6,618 posts

243 months

Thursday 6th January 2011
quotequote all
What make and model is it? If it is a Baxi and you are getting the fan fault light, check the flue outlet for obstructions. They are quite sensitive to them.



shirt

Original Poster:

25,078 posts

225 months

Thursday 6th January 2011
quotequote all
Its a Biasi Garda HE, not sure of the exact model as I left the manual at home. I'll check the flue, hopefully nothing nasty living in there as I am a big wuss smile