I'm looking at the installation instructions for a Worcester-Bosch
combi, in particular the pipework layout for ducting away the condensate.
PDF file (5.6Mb, sorry!) is available he http://tinyurl.com/yfo9w7
(or
http://www.worcester-bosch.co.uk/index.php?fuseaction=site.viewFile&id=126976)

On page 11, in several of the diagrams, it seems to me that the
condensate waste pipe connects to the system in the house without a
trap, or connects to the pipes on the wrong side of an existing trap,
meaning that foul air is connected directly to the atmosphere in the house.

I can't believe that I'm interpreting it right. Any able to clarify please?

Thanks
David

In article ,
Lobster writes:
On page 11, in several of the diagrams, it seems to me that the
condensate waste pipe connects to the system in the house without a
trap, or connects to the pipes on the wrong side of an existing trap,
meaning that foul air is connected directly to the atmosphere in the house.

I can't believe that I'm interpreting it right. Any able to clarify please?

There's probably a trap in the boiler (at least, there is with
my Keston). If the wastepipe is shared with something else (e.g.
a sink, bath, washing machine, etc) which can empty out at a
good rate, I would suggest making sure an air admittance valve
is fitted at the furthest such item from the sewer, so that when
one of these finishes emptying out, the slug of water going off
down the pipe doesn't have any tendancy to suck the trap dry in
the WB.

--
Andrew Gabriel

Andrew Gabriel wrote:
In article ,
Lobster writes:
On page 11, in several of the diagrams, it seems to me that the
condensate waste pipe connects to the system in the house without a
trap, or connects to the pipes on the wrong side of an existing trap,
meaning that foul air is connected directly to the atmosphere in the house.

I can't believe that I'm interpreting it right. Any able to clarify please?

There's probably a trap in the boiler

Well I was thinking that, but looking at the diagram in the manual, they
show the condensate feeding into a tundish near the boiler, and that is
what seems to be open to foul air.

David

On 2006-12-12 09:44:50 +0000, Lobster said:

Andrew Gabriel wrote:
In article ,
Lobster writes:
On page 11, in several of the diagrams, it seems to me that the
condensate waste pipe connects to the system in the house without a
trap, or connects to the pipes on the wrong side of an existing trap,
meaning that foul air is connected directly to the atmosphere in the
house.

I can't believe that I'm interpreting it right. Any able to clarify please?

There's probably a trap in the boiler

Well I was thinking that, but looking at the diagram in the manual,
they show the condensate feeding into a tundish near the boiler, and
that is what seems to be open to foul air.

David

You should certainly have some form of trap before the foul drain.
I did that and also put a tundish next to the boiler as an air break.
Although there is a trap inside the boiler as well, one does not to
have any risk of it emptying because there may be the risk of escape of
fumes into the room.

"Andy Hall" wrote in message
...
On 2006-12-12 09:44:50 +0000, Lobster
said:

Andrew Gabriel wrote:
In article ,
Lobster writes:
On page 11, in several of the diagrams, it seems to me that the
condensate waste pipe connects to the system in the house without a
trap, or connects to the pipes on the wrong side of an existing trap,
meaning that foul air is connected directly to the atmosphere in the
house.

I can't believe that I'm interpreting it right. Any able to clarify
please?

There's probably a trap in the boiler

Well I was thinking that, but looking at the diagram in the manual, they
show the condensate feeding into a tundish near the boiler, and that is
what seems to be open to foul air.

David

You should certainly have some form of trap before the foul drain. I
did that and also put a tundish next to the boiler as an air break.
Although there is a trap inside the boiler as well, one does not to have
any risk of it emptying because there may be the risk of escape of fumes
into the room.

For some reason I can't view the pdf but the manual for a 30/40 CDi
conventional also has condensate pipework on p11. Skipping on to P40 in
"inspection & servicing" there is "To clean the condensate trap" ( the trap
is shown as item 16 on the boiler layout diagram on P7) . This process ends
with "fill the condensate trap with approx 1/4l of water and refit..." very
strange this is not required at commissioning - boiler shipped "wet"?.

PeterK

On 2006-12-12 21:31:48 +0000, "PeterK" said:


"Andy Hall" wrote in message ...
On 2006-12-12 09:44:50 +0000, Lobster said:

Andrew Gabriel wrote:
In article ,
Lobster writes:
On page 11, in several of the diagrams, it seems to me that the
condensate waste pipe connects to the system in the house without a
trap, or connects to the pipes on the wrong side of an existing trap,
meaning that foul air is connected directly to the atmosphere in the
house.

I can't believe that I'm interpreting it right. Any able to clarify please?

There's probably a trap in the boiler

Well I was thinking that, but looking at the diagram in the manual,
they show the condensate feeding into a tundish near the boiler, and
that is what seems to be open to foul air.

David

You should certainly have some form of trap before the foul drain.
I did that and also put a tundish next to the boiler as an air break.
Although there is a trap inside the boiler as well, one does not to
have any risk of it emptying because there may be the risk of escape of
fumes into the room.

For some reason I can't view the pdf but the manual for a 30/40 CDi
conventional also has condensate pipework on p11. Skipping on to P40 in
"inspection & servicing" there is "To clean the condensate trap" ( the
trap is shown as item 16 on the boiler layout diagram on P7) . This
process ends with "fill the condensate trap with approx 1/4l of water
and refit..." very strange this is not required at commissioning -
boiler shipped "wet"?.

PeterK

On the WB web site, go to the installer section and then enter CDI in
the search. Navigate using the Literature tab.

The front cover of the manual describes the CDi conventional as a
condensing boiler, hence the condensation trap.

Whether the piece about filling the trap should be part of
commissioning, I don't know. The trap should fill with condensate
anyway when the boiler is heating from cold, but it does seem
inconsistent.

On Tue, 12 Dec 2006 21:31:48 -0000, "PeterK"
wrote:

For some reason I can't view the pdf but the manual for a 30/40 CDi
conventional also has condensate pipework on p11. Skipping on to P40 in
"inspection & servicing" there is "To clean the condensate trap" ( the trap
is shown as item 16 on the boiler layout diagram on P7) . This process ends
with "fill the condensate trap with approx 1/4l of water and refit..." very
strange this is not required at commissioning - boiler shipped "wet"?.

No, its not shipped wet. When you fire the boiler for the first time
(or after being completely switched off for an extended period) the
boiler fires at minimum for 15 minutes in order to fill the condensate
trap.

The LED display usually alternates between -II- and the flow
temperature while this is in progress.



--