Water dripping from flue? | Bathroom Advice | Plumbers Forums
  • Welcome to PlumbersTalk.net

    Welcome to Plumbers' Talk | The new domain for UKPF / Plumbers Forums. Login with your existing details they should all work fine. Please checkout the PT Updates Forum

Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws

American Visitor?

Hey friend, we're detecting that you're an American visitor and want to thank you for coming to PlumbersTalk.net - Here is a link to the American Plumbing Forum. Though if you post in any other forum from your computer / phone it'll be marked with a little american flag so that other users can help from your neck of the woods. We hope this helps. And thanks once again.

Discuss Water dripping from flue? in the Bathroom Advice area at Plumbers Forums

Messages
30
Good morning from snow free West Country!
My son who lives in East Midlands in a three storey modern house has got a lot of snow and very low temperatures.
His combi boiler is playing up, British Gas have fitted a new circuit board but are coming back because now boiler is running intermittently.
Last night on returning home he gave it a go and it did fire up so decided to run a hot bath. After some time he heard dripping water and it was coming from bottom of boiler!
He switched everything off and checked what he could,pressure was fine and no other leaks found. Eventually the dripping stopped. Boiler is on top floor with vent in the roof and not the wall. Is it possible for the incoming combustion air to condense in these very cold conditions and then drip down into boiler? I can think of nothing else.
Having said that I know it could be a blocked condensate drain but I thought this would stop the boiler? It was still running when he first found it. He knows very little about the pipe work and I have never seen it.
 
Last edited:
I had a similar problem with my old combi boiler. Considerable water pouring down into the boiler itself and then down the wall. At first we thought it was rain leaking through the sleeve where the flu goes through the roof and we had a man into check that - then I noticed that the flow happened even when the weather was dry. A few plumbers later a local guy climbed into the loft and discovered the problem - The balanced flu had completely rusted through between the inner and outer - and the exhaust gas was coming back down the intake causing considerable condensation, and the boiler would frequently cut out. The flu had been installed with a short level section rather than a slope and the water had collected and corroded through.
 
Thank you both for your replies. Chuck, I take it your No was in reply to “can combustion air condense” etc etc.
From the reply from Spondik it does seem possible but my sons boiler would not be that old.
My money is now on a blocked condensate pipe but as I said before, surely that should shut down the boiler before causing a leak.
BG are coming again tomorrow so hopefully, they will get to the bottom of this.
 
Chuck, I take it your No was in reply to “can combustion air condense” etc etc..

My 'no' was a simple (and correct) reply to the specific question you asked about 'air'. Perhaps you meant combustion 'products' in which case Spondik's answer is more relevant.

Either way, this is not something either you or your son should try to fix yourself. It needs to be sorted out by a Gas Safe Regsistered engineer.
 
No I didn’t mean combustion products I meant the incoming fresh air down the outer of the flue pipe. I wondered if in the extreme conditions with the boiler being off for some time snow or ice could have got into it and was melting when the boiler and flue got hot.
As I said I have never seen the boiler, I live about 200 miles away. BG is returning tomorrow, they have the contract. My son has no intention of doing anything to it.
We are simply wondering where the water came from.
 
No I didn’t mean combustion products I meant the incoming fresh air down the outer of the flue pipe. I wondered if in the extreme conditions with the boiler being off for some time snow or ice could have got into it and was melting when the boiler and flue got hot.

In that case, I stand by my original answer, 'no'.
 

Similar plumbing topics

It seems to be a case of having to watch and...
Replies
8
Views
667
  • Question
This issue arose about a year ago. Does anyone...
Replies
0
Views
653
D
As above The Grant instructions tell you to...
Replies
3
Views
927
In principle it's should not drip but in...
Replies
2
Views
6K
  • Question
Many thanks for the advice.
Replies
3
Views
796
Back
Top