Vokera 29HE loosing pressure

[morganlilli]

Definitely sounds like heat ex running into condensate, especially when youre saying condense pipe for quite it's length is warm to touch. Like stokecity says if condensate still dripping when no demand on, then theirs yours problem...had this on many Baxi 105 he's

An update. Had BG out this afternoon and they have completely isolated the boiler - i.e. re-pressurised, switched off and disconnected the various (non-gas) pipes under the boiler. So...will leave this overnight and see what happens in terms of the pressure. No water in the buckets yet! The guys said if the pressure was the same in the morning he would fire up the boiler but leave the condensate disconnected to see if any water was running through when it was 'live'. At least it's helping to move things along.

From everything that has been said here that should at least tell us if its the boiler or the pipes!!

 

[plumber 88]

The main heat exchanger is burst and running down the condensate that's why you can't find a leak

 

[morganlilli]

Here goes with a further update and a few questions. Since last post, had BG in who dug up a bit of the concrete floor in front room and found a leak. This was mended and did solve the problem for a couple of months. We had constant pressure during this time

Unfortunately, earlier this month we then had a further issue with water running hot and cold leading to the boiler being virtually dismantled and the heat exchanger being replaced. The BG guy had a real problem with the washers in the new heat exchanger (i.e. it leaked the first few times he fitted it) but this was eventually sorted. This solved the intermitent water issue BUT THEN...

...you guessed it, we started loosing pressure again :angry_smile: I'm having to repressurise twice a day as I type this and it's soul destroying. We have had BG out again who have checked PRV pipe (no leak), condensate (no leak), Expansion Vessel (which has been pumped up and has held pressure since), and who put some leak sealer in the system. No visible signs of leaks from below the boiler, rads or floor. So I'm thinking leak again...??!!

What I would appreciate thoughts on is:
1) it is much quicker to re-pressurise this time (litterally a few seconds, Vs about 1min last time) - is this significant?
2) when you do re-pressurise and close the filling loop, the pressure drops immediately (1/4 bar roughly) - is this significant?

Finally, when all said and done, if it is a leak again I may consider a complete re-pipe job on the ground floor (pipes on walls - not below ground). I just can't face going through this every few months. Roughly how much should I be paying for this (3 bed house in South).

Thanks all.

 

[neily01]

i have had a couple of problems with one of these. couldnt find where we were losing pressure isolated system in various ways bagged prv, no idea! turned out like plumber 88 said the main htg ex split and was leaking into condensate so that was why we couldnt find it. a year later on a service got all sorts of combustion figures couldnt adjust gas valve at all they were back out replacing that! have fitted alot of vokeras but this boiler is the new standard for the linea one so wont be fitting anymore of them!!!

 

[Millsy 82]

If you have pipework under a concrete floor that has already sprung a leak the chances are it has sprung another leak under the floor.

I would cap the pipes off before they run under the ground for a couple of days to check to see if it still leaks if it stops repipe the system as it could be the pipe wasnt protected when it was installed.