My old (non-condensing) boiler is on its last legs, and will probably
need replacing when the weather is warmer in the Spring. However, it
is going to be difficult to route the condensate pipe.

I live in a bungalow, and the kitchen is galley style, doors north and
south, sink (with gully outside) on the east side, boiler on the west
side. The routing of the flue is easiest if the boiler stays on the
west side of the kitchen, but I have the problem of how to route the
condensate drain.

Options seem to be (i) use a condensate pump to lift the condensate
into the attic, run across the attic and down the east wall internally
or externally, or (ii) use an inverted syphon to take the condensate
under the suspended wooden floor. The inverted syphon is a big
U-tube, as used by the Romans to take aqueducts across valleys. I
have a feeling the inverted syphon was suggested by someone on
uk.d-i-y, but I cannot locate the post on Google groups.

My preference is for the inverted syphon -- no pump to go wrong and
easier to hide the pipe neatly. However, I feel a bit uncomfortable
about having perhaps 1.5 litres condensate sitting in the pipe under
the floor (20mm i.d. pipe 5 m long). I would be careful to prevent
freezing, running it parallel to existing hot pipes or using a trace
heater.

Is there any problem with the inverted syphon that I have missed?
Would I fall foul of any regulations with this solution?

MJA

MJA wrote:
My old (non-condensing) boiler is on its last legs, and will probably
need replacing when the weather is warmer in the Spring. However, it
is going to be difficult to route the condensate pipe.

I live in a bungalow, and the kitchen is galley style, doors north and
south, sink (with gully outside) on the east side, boiler on the west
side. The routing of the flue is easiest if the boiler stays on the
west side of the kitchen, but I have the problem of how to route the
condensate drain.

Options seem to be (i) use a condensate pump to lift the condensate
into the attic, run across the attic and down the east wall internally
or externally, or (ii) use an inverted syphon to take the condensate
under the suspended wooden floor. The inverted syphon is a big
U-tube, as used by the Romans to take aqueducts across valleys. I
have a feeling the inverted syphon was suggested by someone on
uk.d-i-y, but I cannot locate the post on Google groups.

My preference is for the inverted syphon -- no pump to go wrong and
easier to hide the pipe neatly. However, I feel a bit uncomfortable
about having perhaps 1.5 litres condensate sitting in the pipe under
the floor (20mm i.d. pipe 5 m long). I would be careful to prevent
freezing, running it parallel to existing hot pipes or using a trace
heater.

Is there any problem with the inverted syphon that I have missed?
Would I fall foul of any regulations with this solution?

Why can't it just go down through the worktop, then along to the sink waste?

On 16 Dec 2012 20:13:06 GMT, MJA wrote:

I live in a bungalow, and the kitchen is galley style, doors north and
south, sink (with gully outside) on the east side, boiler on the west
side. The routing of the flue is easiest if the boiler stays on the
west side of the kitchen, but I have the problem of how to route the
condensate drain.

West side external wall? Take the condensate pipe through that and into a
condensate soakaway:

http://www.mcalpineplumbing.com/trap.../soakaway.html

Installation .pdf is available, the snag is probably the 500 mm minimum
distance from the building. Remember to increase the pipe to 32mm before
exiting the building. 32mm is much less prone to freezing and blockage
than 22mm.

--
Cheers
Dave.

On Dec 16, 8:13*pm, MJA wrote:
My old (non-condensing) boiler is on its last legs, and will probably
need replacing when the weather is warmer in the Spring. *However, it
is going to be difficult to route the condensate pipe.

I live in a bungalow, and the kitchen is galley style, doors north and
south, sink (with gully outside) on the east side, boiler on the west
side. *The routing of the flue is easiest if the boiler stays on the
west side of the kitchen, but I have the problem of how to route the
condensate drain.

Options seem to be (i) use a condensate pump to lift the condensate
into the attic, run across the attic and down the east wall internally
or externally, or (ii) use an inverted syphon to take the condensate
under the suspended wooden floor. *The inverted syphon is a big
U-tube, as used by the Romans to take aqueducts across valleys. *I
have a feeling the inverted syphon was suggested by someone on
uk.d-i-y, but I cannot locate the post on Google groups.

My preference is for the inverted syphon -- no pump to go wrong and
easier to hide the pipe neatly. *However, I feel a bit uncomfortable
about having perhaps 1.5 litres condensate sitting in the pipe under
the floor (20mm i.d. pipe 5 m long). *I would be careful to prevent
freezing, running it parallel to existing hot pipes or using a trace
heater.

Is there any problem with the inverted syphon that I have missed?
Would I fall foul of any regulations with this solution?

MJA

I assume your flue/air intake is going through the roof?
The best thing would be to excavate the gully and bring the pipe
(enlarged) through the wall and into the back of that with due
precautions.
You can get gullies with back entries intended for rainwater
connections.
Depends on the relative height of the floor and outside drain invert
level.

On Sun, 16 Dec 2012 20:13:06 +0000, MJA wrote:

My old (non-condensing) boiler is on its last legs, and will probably
need replacing when the weather is warmer in the Spring. However, it is
going to be difficult to route the condensate pipe.

I live in a bungalow, and the kitchen is galley style, doors north and
south, sink (with gully outside) on the east side, boiler on the west
side. The routing of the flue is easiest if the boiler stays on the
west side of the kitchen, but I have the problem of how to route the
condensate drain.

Options seem to be (i) use a condensate pump to lift the condensate into
the attic, run across the attic and down the east wall internally or
externally, or (ii) use an inverted syphon to take the condensate under
the suspended wooden floor. The inverted syphon is a big U-tube, as
used by the Romans to take aqueducts across valleys. I have a feeling
the inverted syphon was suggested by someone on uk.d-i-y, but I cannot
locate the post on Google groups.

'twas I: I've used that trick on a couple of occasions. It's not by the
book but it does work because the condensate is clean (you would NOT want
to try that with normal waste water e.g. from a sink, basin or bath as
sediment would settle out and block the bottom of the U-section).


BTW it's just a 'U' shape, nothing syphonic about it.


--
John Stumbles -- http://yaph.co.uk

Many hands make light work. Too many cooks spoil the broth.

Thanks to all the responders.

On 2012-12-18, YAPH wrote:
On Sun, 16 Dec 2012 20:13:06 +0000, MJA wrote:

My old (non-condensing) boiler is on its last legs, and will probably
need replacing when the weather is warmer in the Spring. However, it is
going to be difficult to route the condensate pipe.

.....

Options seem to be (i) use a condensate pump to lift the condensate into
the attic, run across the attic and down the east wall internally or
externally, or (ii) use an inverted syphon to take the condensate under
the suspended wooden floor. The inverted syphon is a big U-tube, as
used by the Romans to take aqueducts across valleys. I have a feeling
the inverted syphon was suggested by someone on uk.d-i-y, but I cannot
locate the post on Google groups.

'twas I: I've used that trick on a couple of occasions. It's not by the
book but it does work because the condensate is clean (you would NOT want
to try that with normal waste water e.g. from a sink, basin or bath as
sediment would settle out and block the bottom of the U-section).

Thanks, I knew I had seen the suggestion before!

BTW it's just a 'U' shape, nothing syphonic about it.

True, but language is not logical, and the search term "inverted
syphon" gives lots of fascinating hits from Roman to modern times!

I worry about regulations because I have to agree it with the gas
fitter I employ to install the new boiler, and ensure any future
maintainer doesn't condemn the installation because it is unusual.

Regards,

MJA



P.S. In case my original message was not very clear, here is some
ASCII art showing a plan and cross-section.

I prefer not to have the flue exiting through the roof, because of the
risk of leaks. A flue through the east wall would send the plume
across a path at low height. This leaves only the north wall for the
flue terminal, taking the flue vertically into the attic and
horizontally out of the gable end so the plume would be well above
head height and away from windows and doors.



Plan View ^
--------- Flue |
|| | North
-----+-||----------- +---------------+ |
|+--+ / |
|| | / |
|| | / |
|+--+ |
| |
| Proposed |
| new boiler |
| |
| |
| |
| |
| |
Lounge | Kitchen |
| |
+...........................................+
| | | |
v A |+---+ | v A
|| | Old |
|| | Boiler |
|+---+ |
+-----+ +-----|
| | | |+--+
| | | || |
| H/W | | |+--+
| | | | Gully
| Cyl.| |Sink |
| | | |
| | | |
| | / | |
| | / | |
| | / | |
+-----+--------+ ---------+-----+
|
|
Hall |
|

Section A-A
-----------

----
----
----
----
----
/\ ----
|| ----
|| Flue vertical ----
|| then horizontal ----
|| through gable end ----
|| -----
+-||--------------------------------+ |
| || |---
|+--+ |
|| | New Boiler |
|| | Location |
|| | |
|+--+ |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | /-\ |
| | | | |
| | | \---\
| | | | | Gully
+-|-----------------------------|---+ |
\-----------------------------/ |+|-+
Possible condensate pipe |
route

On Wed, 19 Dec 2012 16:15:58 +0000, MJA wrote:

P.S. In case my original message was not very clear, here is some ASCII
art showing a plan and cross-section.

---8---

you need to do that in a fixed-width font (or plain text) - that came out
as abstract art ;-/

--
John Stumbles -- http://yaph.co.uk

"Sir, if you were my husband, I would poison your drink." -- Lady Astor
"Madam, if you were my wife, I would drink it." -- Winston Churchill

On 22/12/2012 18:33, YAPH wrote:
On Wed, 19 Dec 2012 16:15:58 +0000, MJA wrote:

P.S. In case my original message was not very clear, here is some ASCII
art showing a plan and cross-section.

---8---

you need to do that in a fixed-width font (or plain text) - that came out
as abstract art ;-/

Works perfectly for me.

Isn't it a case of you needing to ** view ** using a fixed width font
(having been created appropriately for that).

--
Rod

On Sat, 22 Dec 2012 18:46:00 +0000, polygonum wrote:

P.S. In case my original message was not very clear, here is some
ASCII art showing a plan and cross-section.

you need to do that in a fixed-width font (or plain text) - that came
out as abstract art ;-/

Works perfectly for me.

Worked fine for me and must have take an while to do as well...

Isn't it a case of you needing to ** view ** using a fixed width font

Yep, needs to be created and viewed with a fixed width font.

WWWWWWWWWW
iiiiiiiiii

Those two lines should be the same length in a fixed pitch font.

--
Cheers
Dave.