Vaillant Horizontal Flue Leaking At joints

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Hey Folks!

I have a thorny issue with a flue installed at the same time as a new ecotec boiler about a year ago. I noticed a couple of months ago that it was leaking from two of the connector joints connecting the extension pieces of the flue together. I called the original fitter - he came, said it was all installed correctly (I guess I should have watched what he did to ascertain that) and said that Vaillant flues “ have this problem” and that I should call them. Clearly that’s rubbish, but i’d like to know what the problem could be. I’m not having him back here again, that’s a lost cause, he either doesn’t know how, or is not willing to, fix it.

After he had visited one of the joints had stopped leaking, (I think) - you can see a little green strip of paper taped to the pipe as my test to make certain)but the other one remains leaking...

I did call Vaillant, they told me (unsurprisingly) to get another plumber....

It looks to me like it’s installed at the correct angle (believe 1-3 degrees sloping back to boiler).

Attached a couple of pictures...

Any ideas?

Thanks in advance folks!
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Looks like it's running parallel to the ceiling joists
 
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First of all how bad is the leakage on the flu?
If the boiler is not cutting out and the analyser readings are fine I wouldn’t worry about it to much. If the seals have perished the analyser reading should be off. But 100% get a qualified heating engineer to take a look. I’d prefer if the flu had more of a fall if I’m honest.
 
Had this before on a gloworm boiler. The internal flue seals were leaking due to inadequate fall back on the flue.

Below is from the manufacturers instructions. If the flue is horizontal and 4 metres in length it requires 200mm fall back to the boiler.
 

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Should be 44mm a metre fall back to the boiler so. You have 3 mtrs of added flue beyond the standard length so the hole in the wall should have been 132mm higher than the turret. Its not fitted to manufacturers instructions.
Also condense shouldnt be able to leak out of the internal fluepipe it sounds like a seal has been twisted and should be looked at urgently.
Contact Gassafe and they will invite the installer to put it right at his expense.
 
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looks like there's not much of a fall on that to me (if you look at the course of bricks).
you wont be able to tell its fitted correctly without taking it apart, but you can't do that, so you'll have to call a Gas Safe dude in.
A blind man could see thats not fitted correctly :)
 
Very much appreciate all your feedback folks. I’m going to measure the fall exactly and let you all know. The installation instructions for this flue (for the competent person - ha ha) I have got online tell me a fall of 1-3 degrees, which would be a minimum of 20 - 50mm per meter. (extract and link below)

https://www.vaillant.co.uk/downloads/834449-161-372979.pdf (Page 16)

As for getting the installer back I think it might be a dead loss... he wound up his company and got a job :-s so now he tells me he’s no longer personally gas safe - only through the new company. Does anyone know if I have any fall back now that he's no longer working as his own company if it does turn out that the fall (or indeed any other install matter) is the issue?

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he tells me he’s no longer personally gas safe - only through the new company

Indeed, we have personal registration and company registration. If he is now only working under his employers registration he would need their express permission (read assumed liability) to work on your installation. You might have recourse through Gas Safe though.
 
"looks like there's not much of a fall on that to me"


Fall mentioned. Done.



Do you think the fall is the only aspect of a flue installation that could cause a leak? And no, I won't lighten up on your command. I'm having a schitty day. :p
 
"looks like there's not much of a fall on that to me"


Fall mentioned. Done.



Do you think the fall is the only aspect of a flue installation that could cause a leak? And no, I won't lighten up on your command. I'm having a schitty day. :p
Not my problem, but you dont know its condense, it could just as easy be rain water,or an installer having a schitty day and couldn't be bothered to clean up the cut end of his flue and pushed the flue gasket out when he assembled it, who knows? Without being rude, having spent my entire working life as a gas fitter and serving a five year apprenticeship, I probably know a thing or two, just because my RGI membership has expired doesn't make me an idiot theres alot of idiots out there who have their cirtification, the installer of that flue for one.
 

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