I had a new condensing boiler fitted in April, and apart from being a
bit noisy (a high-pitched whine) all's been well. However, I have
noticed a puddle forming under the flue, and it seems to be turning into
a problem. Here's a couple of pics:

https://sites.google.com/site/patchoulian/home/boiler-2

I've measured the water as about 2.5cl per 8 hours of c/h use. Is this
about right? Also, it does seem to be a lot of water forming from a very
small surface area - the lip of the flue. All the pipework seems water
tight.

TIA, Rob

In article om,
Rob writes:
I had a new condensing boiler fitted in April, and apart from being a
bit noisy (a high-pitched whine) all's been well. However, I have
noticed a puddle forming under the flue, and it seems to be turning into
a problem. Here's a couple of pics:

https://sites.google.com/site/patchoulian/home/boiler-2

I've measured the water as about 2.5cl per 8 hours of c/h use. Is this
about right? Also, it does seem to be a lot of water forming from a very
small surface area - the lip of the flue. All the pipework seems water
tight.

I can't see any reason the end of the flue is cut to form a water
protection hood. It wouldn't matter if rain went down it (if it's
been installed with correct slope back into the boiler). I suspect
it's the condensation on that hood which is dripping off, and would
be mostly solved if you cut it off. I presume it's just the exhaust
and the air inlet is somewhere not visible in the picture?

My condensing boiler flue points up anyway. Once a year I pour a
couple of pints of water down it to wash away any debris collecting
in the bottom of the heat exchanger, which is much easier than
opening up the heat exchanger, which then always needs new seals.
(I don't know if that's safe for all condensing boilers though,
and never pour water into the air intake.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 15/10/2010 16:26, Andrew Gabriel wrote:
In raweb.com,
writes:
I had a new condensing boiler fitted in April, and apart from being a
bit noisy (a high-pitched whine) all's been well. However, I have
noticed a puddle forming under the flue, and it seems to be turning into
a problem. Here's a couple of pics:

https://sites.google.com/site/patchoulian/home/boiler-2

I've measured the water as about 2.5cl per 8 hours of c/h use. Is this
about right? Also, it does seem to be a lot of water forming from a very
small surface area - the lip of the flue. All the pipework seems water
tight.

I can't see any reason the end of the flue is cut to form a water
protection hood. It wouldn't matter if rain went down it (if it's
been installed with correct slope back into the boiler). I suspect
it's the condensation on that hood which is dripping off, and would
be mostly solved if you cut it off. I presume it's just the exhaust
and the air inlet is somewhere not visible in the picture?


Yes - condensation forms on the hood and drips down. I assume it's an
exhaust only (Ideal Logic+) although I hadn't thought about where it
gets its air for combustion - the room?! There's no inlet I can see.

My condensing boiler flue points up anyway. Once a year I pour a
couple of pints of water down it to wash away any debris collecting
in the bottom of the heat exchanger, which is much easier than
opening up the heat exchanger, which then always needs new seals.
(I don't know if that's safe for all condensing boilers though,
and never pour water into the air intake.)


Maybe cutting the flue's the way forward. I'd better get the installer
back because it's damaging the patio. I just wanted to pre-empt a 'They
all do that, sir' type discussion.

Rob

On 15 Oct, 16:10, Rob wrote:
I had a new condensing boiler fitted in April, and apart from being a
bit noisy (a high-pitched whine) all's been well. However, I have
noticed a puddle forming under the flue, and it seems to be turning into
a problem. Here's a couple of pics:

https://sites.google.com/site/patchoulian/home/boiler-2

I've measured the water as about 2.5cl per 8 hours of c/h use. Is this
about right? Also, it does seem to be a lot of water forming from a very
small surface area - the lip of the flue. All the pipework seems water
tight.

TIA, Rob

I assume there is a drain for the condensate close to the boiler?
(Pipe about 20mm diameter.)
It's not normal for condensate to be blown out of the exhaust. There
is a tray under the heat exchanger in the boiler that should catch all
the condensate which is drained away in the 20mm plastic pipe to a
gulley.
The condensate is very acid due to CO2 dissolved in it, it will
definitely make holes in cement eventually.

On 15/10/2010 17:48, harry wrote:
On 15 Oct, 16:10, wrote:
I had a new condensing boiler fitted in April, and apart from being a
bit noisy (a high-pitched whine) all's been well. However, I have
noticed a puddle forming under the flue, and it seems to be turning into
a problem. Here's a couple of pics:

https://sites.google.com/site/patchoulian/home/boiler-2

I've measured the water as about 2.5cl per 8 hours of c/h use. Is this
about right? Also, it does seem to be a lot of water forming from a very
small surface area - the lip of the flue. All the pipework seems water
tight.

TIA, Rob

I assume there is a drain for the condensate close to the boiler?
(Pipe about 20mm diameter.)
It's not normal for condensate to be blown out of the exhaust. There
is a tray under the heat exchanger in the boiler that should catch all
the condensate which is drained away in the 20mm plastic pipe to a
gulley.
The condensate is very acid due to CO2 dissolved in it, it will
definitely make holes in cement eventually.

Yes - there is a separate condensate pipe. It's the black one running
under the doors, on to a drain. Thanks for the reply.

Rob

In article om,
Rob writes:
On 15/10/2010 17:48, harry wrote:
On 15 Oct, 16:10, wrote:
I had a new condensing boiler fitted in April, and apart from being a
bit noisy (a high-pitched whine) all's been well. However, I have
noticed a puddle forming under the flue, and it seems to be turning into
a problem. Here's a couple of pics:

https://sites.google.com/site/patchoulian/home/boiler-2

I've measured the water as about 2.5cl per 8 hours of c/h use. Is this
about right? Also, it does seem to be a lot of water forming from a very
small surface area - the lip of the flue. All the pipework seems water
tight.

TIA, Rob

I assume there is a drain for the condensate close to the boiler?
(Pipe about 20mm diameter.)
It's not normal for condensate to be blown out of the exhaust. There
is a tray under the heat exchanger in the boiler that should catch all
the condensate which is drained away in the 20mm plastic pipe to a
gulley.
The condensate is very acid due to CO2 dissolved in it, it will
definitely make holes in cement eventually.

Yes - there is a separate condensate pipe. It's the black one running
under the doors, on to a drain. Thanks for the reply.

I didn't notice that. It's badly installed and will freeze in
a cold winter. Doesn't instill confidence in the other parts
of the installation I can't see.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 15/10/2010 16:56, Rob wrote:
On 15/10/2010 16:26, Andrew Gabriel wrote:

My condensing boiler flue points up anyway. Once a year I pour a
couple of pints of water down it to wash away any debris collecting
in the bottom of the heat exchanger, which is much easier than
opening up the heat exchanger, which then always needs new seals.
(I don't know if that's safe for all condensing boilers though,
and never pour water into the air intake.)

Maybe cutting the flue's the way forward. I'd better get the installer
back because it's damaging the patio. I just wanted to pre-empt a 'They
all do that, sir' type discussion.

Gas installers get very twitchy about doing anything at all to
manufacturer-supplied flues, even something as seemingly innoccuous as
trimming this hood affair.

My previous boiler was an early condensing model, built before the
current existing plethora of flues were available to deal with awkward
plumes - like the one in the OP's photos. My plume was directed towards
paintwork on the adjacent garage, so I fabricated a sheet metal
deflector and postitioned it several inches away from the opening of the
flue, to divert the water vapour diagonally upwards. Got a flea in my
ear from the CORGI man for that one - though I really can't see what
possible harm could have been done by it.

Could the angled end of the OP's flue simply be rotated 180 degrees to
solve the dripping problem?

David

On 15/10/2010 18:38, Andrew Gabriel wrote:
In raweb.com,
writes:
On 15/10/2010 17:48, harry wrote:
On 15 Oct, 16:10, wrote:

Yes - there is a separate condensate pipe. It's the black one running
under the doors, on to a drain. Thanks for the reply.

I didn't notice that. It's badly installed and will freeze in
a cold winter. Doesn't instill confidence in the other parts
of the installation I can't see.

Blimey, yes - apart from being very long and exposed, it appears to have
a slight *upward* slope just below the door? Definitely bad news...

David

"Lobster" wrote in message
...
On 15/10/2010 18:38, Andrew Gabriel wrote:
In raweb.com,
writes:
On 15/10/2010 17:48, harry wrote:
On 15 Oct, 16:10, wrote:

Yes - there is a separate condensate pipe. It's the black one running
under the doors, on to a drain. Thanks for the reply.

I didn't notice that. It's badly installed and will freeze in
a cold winter. Doesn't instill confidence in the other parts
of the installation I can't see.

Blimey, yes - apart from being very long and exposed, it appears to have a
slight *upward* slope just below the door? Definitely bad news...

David



My combi has a flue which in colder weather looks like it is smoking due to
the amount of condensation (not visible in summer)
Based on that I reckon your angled pipe would drip a lot and thats the
cause.

On the condensate pipe mine is only exposed 3 inches on the outside and it
froze twice last year, but will insulate it before this winter sets in.
If it does freeze a couple of kettles of hot water soon sorts it.

On 15 Oct, 18:23, Rob wrote:
On 15/10/2010 17:48, harry wrote:





On 15 Oct, 16:10, *wrote:
I had a new condensing boiler fitted in April, and apart from being a
bit noisy (a high-pitched whine) all's been well. However, I have
noticed a puddle forming under the flue, and it seems to be turning into
a problem. Here's a couple of pics:

https://sites.google.com/site/patchoulian/home/boiler-2

I've measured the water as about 2.5cl per 8 hours of c/h use. Is this
about right? Also, it does seem to be a lot of water forming from a very
small surface area - the lip of the flue. All the pipework seems water
tight.

TIA, Rob

I assume there is a drain for the condensate close to the boiler?
(Pipe about 20mm diameter.)
It's not normal for condensate to be blown out of the exhaust. *There
is a tray under the heat exchanger in the boiler that should catch all
the condensate which is drained away in the 20mm plastic pipe to a
gulley.
The condensate is very acid due to CO2 dissolved in it, it will
definitely make holes in cement eventually.

Yes - there is a separate condensate pipe. It's the black one running
under the doors, on to a drain. Thanks for the reply.

Rob- Hide quoted text -

- Show quoted text -

Make sure this pipe has sufficient falland that the condense is able
to drain away freely. It sounds to me that this might not be the case.

On 16/10/2010 07:47, harry wrote:
On 15 Oct, 18:23, wrote:
On 15/10/2010 17:48, harry wrote:





On 15 Oct, 16:10, wrote:
I had a new condensing boiler fitted in April, and apart from being a
bit noisy (a high-pitched whine) all's been well. However, I have
noticed a puddle forming under the flue, and it seems to be turning into
a problem. Here's a couple of pics:

https://sites.google.com/site/patchoulian/home/boiler-2

I've measured the water as about 2.5cl per 8 hours of c/h use. Is this
about right? Also, it does seem to be a lot of water forming from a very
small surface area - the lip of the flue. All the pipework seems water
tight.

TIA, Rob

I assume there is a drain for the condensate close to the boiler?
(Pipe about 20mm diameter.)
It's not normal for condensate to be blown out of the exhaust. There
is a tray under the heat exchanger in the boiler that should catch all
the condensate which is drained away in the 20mm plastic pipe to a
gulley.
The condensate is very acid due to CO2 dissolved in it, it will
definitely make holes in cement eventually.

Yes - there is a separate condensate pipe. It's the black one running
under the doors, on to a drain. Thanks for the reply.

Rob- Hide quoted text -

- Show quoted text -

Make sure this pipe has sufficient falland that the condense is able
to drain away freely. It sounds to me that this might not be the case.

Yes - thanks to you and others for pointing that out, quite right too. I
think the down pipe just needs trimming an inch or two to encourage the
fall needed, but the chap could have done that at the time. I'll ask him
back to look at the condensation as well.

Rob