Water dribbling from combi flue

Discussion in 'Plumbers' Talk' started by phobia, Oct 19, 2008.

  1. phobia

    phobia New Member

    Hi
    I have a Vaillant ecotech plus combi. Ever since it was fitted, water has dribbled out of the flue. When I first noticed it, I called the plumber back and he said it was normal for a combi. Is this true?
    Unfortunately, I've left it until it's just out of warranty, but now that the heating season has started and the central heating is on, water is once again dribbling out of it and wetting the wall quite badly. I've been having a look at a couple nearby and they don't seem to be having the same problem, or not to the same extent. Other than this, it's been working fine for quite a long time.
    Have you any advice?
    Thanks
  2. Captain Leaky

    Captain Leaky New Member

    They do plume water vapour, this can condense and cause noticeable damp sometimes. I doubt it is anything to worry about.
  3. mantor

    mantor New Member

    When it was installed the flue should have been sloped back to the boiler by about 3 degrees. So any condensate drains back through the heat exchanger into the trap. It sounds like it's sloping the wrong way.
  4. mully123

    mully123 New Member

    Ask Bum/spec.Hes got a degee.LOL
  5. devils advocate

    devils advocate New Member

    ...and will probably mark the wall over time, being slightly acidic.

    The actual presence of water is ok - so not a prob with the boiler itself (presuming it's a condensing type?) - but IF the flue is sloping the 'wrong' way allowing the condensate to come out the end, then it wasn't a perfect install in the first place, so I reckon you could ask the installer to sort it.

    There will always be some water dripping from the end. tho', as the condensate forms droplets there.
    The other flues you've looked at nearby might not be from condensing boilers, so won't be producing this plume (or, rather, it fires all the steam out well in to the air!).
  6. rome60

    rome60 New Member

    Seems to me that the condense drain pipe which spills at intervals has"nt been taken to a drain & left just poking out of the wall.:(
  7. mully123

    mully123 New Member

    Makes me laugh,up a rickkety old ladder,with a **** big core drill,that could snap yer arm off if the clutch dont work,trying to drill so that your within 3 degrees.Wot a f***G laff.Ask the counter Rat if hes ever done one{dont think so}.Bum/spec would have a theodolite on his,the big Jessy.LOL
  8. mantor

    mantor New Member

    I know what you're saying mully, I gofrom the inside if I'm upstairs(* the dust). I find the easy way is to use a five inch core drill and just go straight through, you can easy get your slope inside the hole.

    [Edited by: admin6]
  9. Nah, you want something you can get your head through!


    Here's one I did earlier.
  10. tomplum

    tomplum New Member

    core drill ? i use the old fashioned hammer and chisel,you would sruggle getting a square core hole for balanced flues :)
  11. devils advocate

    devils advocate New Member

    Midnight, I'd be amazed if your head could fit through even that.
  12. phobia

    phobia New Member

    Hi guys
    Many thanks for the advice from all of you.
    Mantor, I think you've diagnosed this problem perfectly. I've had the end off the duct and pushed a small spirit level up it. It looks as if the duct is sloping through the wall downwards about 15-20mm instead of backwards towards the boiler.
    The hole through the wall is quite a bit bigger than the duct and I could just ease it up a little to get the slope right except for a couple of pieces of brick in the way. I'm going to get a longish drill bit to clear these and then move it and mortar it in position. I'll let you know how it goes
    Thanks again.
  13. mully123

    mully123 New Member

    Well done, you liverpudlian git.;)
  14. devils advocate

    devils advocate New Member

    Phobia, do you really think you should simply 'ease' the flue up by 20mm+ (I presume you intend to go beyond horizontal t'other way?).

    I'd hate to think a join could open up...
  15. devils advocate

    devils advocate New Member

    I'd be inclined to call out the installer - after all, this isn't technically a warranty claim, but a correction of an tatty install in the first place.
  16. tackleburger

    tackleburger New Member

    a theodolite on his,the big Jessy.LOL

    You use a 127mm core gives you plenty play to get the angle right. You clearly haven't done a flue yet once you do you'll realise a decent core drill won't have a problem with this. If you have you should get decent tools mate.
  17. tackleburger

    tackleburger New Member

    Phobia,

    Get a second opinion on this sound ify to me. Shouldn't dribble like you are saying odd drip maybe. He should sort this out.
  18. phobia

    phobia New Member

    Thanks for the concern devil's advocate. There are no joint on the duct except for where it connects to the boiler with a clamp. When I've cleared the pieces of brick, I think it will move up and down completely freely. If it doesn't and there seems to be the slightest stress on it, I'll call out a plumber. Unfortunately it won't be the same one because I can't seem to contact him any longer.
    Talk to you later
  19. devils advocate

    devils advocate New Member

    Phobia, if there aren't any joints, it would suggest that only the 'standard' flue is used - around 3' long?

    UNLESS the Vaillant has some cunning adjustable connection I don't know of (and it's quite possible...) then there simply isn't any room to 'flex' the flue.

    I have a Glow Worm (same company) and the flue is screwed down onto the boiler top, and the sections slip over each other and are held by small self-tapers. Just ain't going to move...

    (Mind you, it's 4 years old, so designs might have changed.)

    Really - look at the joints carefully when you try and move it.
  20. tomplum

    tomplum New Member

    take it from me Devs, there is plenty scope to move the flue without fear of joints 'popping out'

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