In our terraced house, we have a Ferroli Modena 102 combi in the
kitchen, with a horizontal 100mm concentric flue of 0.5m length, ending
on the outside wall which at that point is part of a single-storey
extension to our house. Unfortunately, it's rather close to next door's
kitchen door and patio, and the smell of the initial exhaust when the
boiler starts up is quite noticeable.

According to the manufacturer's manual, the maximum flue length is 4m,
but any bend counts as 1m, so a horizontal flue like mine, attached to
the top of the boiler by a 90deg bend, has a maximum length of 3m, after
the bend.

Fine, I thought, I can add a 90deg bend where the flue emerges from the
wall, and then a 1.5m concentric flue going vertically upwards to end
about half a metre above the top of the wall. That would be an
effective length of 0.5 (existing) + 1 (new bend) + 1.5 (new flue) = 3m.
But my local Corgi-registered plumber says that you can't mix horizontal
and vertical flues in this way, and he says Ferroli confirmed this to
him. The only answer would be a new vertical flue system which would
have to pass through the existing flat roof, which I am reluctant to do.

If the boiler will accept either horizontal or vertical flues, why can't
you mix them?
--
Richard J.
(to e-mail me, swap uk and yon in address)

"Richard J." wrote in message
...
In our terraced house, we have a Ferroli Modena 102 combi in the
kitchen, with a horizontal 100mm concentric flue of 0.5m length, ending
on the outside wall which at that point is part of a single-storey
extension to our house. Unfortunately, it's rather close to next door's
kitchen door and patio, and the smell of the initial exhaust when the
boiler starts up is quite noticeable.

According to the manufacturer's manual, the maximum flue length is 4m,
but any bend counts as 1m, so a horizontal flue like mine, attached to
the top of the boiler by a 90deg bend, has a maximum length of 3m, after
the bend.

Fine, I thought, I can add a 90deg bend where the flue emerges from the
wall, and then a 1.5m concentric flue going vertically upwards to end
about half a metre above the top of the wall. That would be an
effective length of 0.5 (existing) + 1 (new bend) + 1.5 (new flue) = 3m.
But my local Corgi-registered plumber says that you can't mix horizontal
and vertical flues in this way, and he says Ferroli confirmed this to
him. The only answer would be a new vertical flue system which would
have to pass through the existing flat roof, which I am reluctant to do.

If the boiler will accept either horizontal or vertical flues, why can't
you mix them?

Ask Ferroli: it depends what they specify for your boiler. There isn't any
fundamental rule against mixing horizontal and vertical runs of a balanced
flue (and I'm a bit surprised if they say you can't) but the manufacturer's
instructions are effectively law in this matter. Might be worth checking
with them for yourself: it should be in the installation manual which you
should have (if it's also the service manual). If not you should be able to
get one from them, either online or by phoning them. Or there may be a
separate manual covering flueing options, which you should also be able to
get from them.

That's up to what Ferroli will allow. I have a mixed vertical/horizontal
flue system on my Worcester Bosch Greenstar. Although no mention was made of
this configuration in the installation instructions, it was pretty obvious
through extrapolation what the performance would be and a call to their
technical helpline confirmed that they could see no reason not to install
such a system.

In my case it started with the horizontal turret of the horizontal system,
about 1m length, then a 90 degree bend upwards into the vertical terminal
through the roof.

I suspect that your proposed solution would be just fine, but you mustn't
install something that the manufacturer forbids. There may be some
incompatibility that isn't apparent to you.

Christian.

In article , Richard
J. writes
In our terraced house, we have a Ferroli Modena 102 combi in the
kitchen, with a horizontal 100mm concentric flue of 0.5m length, ending
on the outside wall which at that point is part of a single-storey
extension to our house. Unfortunately, it's rather close to next door's
kitchen door and patio, and the smell of the initial exhaust when the
boiler starts up is quite noticeable.

According to the manufacturer's manual, the maximum flue length is 4m,
but any bend counts as 1m, so a horizontal flue like mine, attached to
the top of the boiler by a 90deg bend, has a maximum length of 3m, after
the bend.

Fine, I thought, I can add a 90deg bend where the flue emerges from the
wall, and then a 1.5m concentric flue going vertically upwards to end
about half a metre above the top of the wall. That would be an
effective length of 0.5 (existing) + 1 (new bend) + 1.5 (new flue) = 3m.
But my local Corgi-registered plumber says that you can't mix horizontal
and vertical flues in this way, and he says Ferroli confirmed this to
him. The only answer would be a new vertical flue system which would
have to pass through the existing flat roof, which I am reluctant to do.

If the boiler will accept either horizontal or vertical flues, why can't
you mix them?

I don't see anything wrong with what you suggest and it would appear that
ferroli don't either: If you take a look at the ferroli website & go to the
Modena page, then to Flueing, there is a picture of possible configurations
on the bottom left. The two lowest and leftmost boilers in that picture have
2x90deg bends with vertical exit (although they don't go above the roofline)
and second from right in the top storey has 2x45deg bends and goes
through the roof. If 2x90 is indeed off limits, then 2x45 and a slant opening
in your wall sounds like it would work.

Could be your guy is telling or being told porkies. Try to talk to someone at
frerroli to clarify the situation, if no joy then print the pic & show to your
corgi (silly snappy dogs, never liked tem ;-).
--
fred

"fred" wrote in message ...
In article , Richard
J. writes
In our terraced house, we have a Ferroli Modena 102 combi in the
kitchen, with a horizontal 100mm concentric flue of 0.5m length, ending
on the outside wall which at that point is part of a single-storey
extension to our house. Unfortunately, it's rather close to next door's
kitchen door and patio, and the smell of the initial exhaust when the
boiler starts up is quite noticeable.

According to the manufacturer's manual, the maximum flue length is 4m,
but any bend counts as 1m, so a horizontal flue like mine, attached to
the top of the boiler by a 90deg bend, has a maximum length of 3m, after
the bend.

Fine, I thought, I can add a 90deg bend where the flue emerges from the
wall, and then a 1.5m concentric flue going vertically upwards to end
about half a metre above the top of the wall. That would be an
effective length of 0.5 (existing) + 1 (new bend) + 1.5 (new flue) = 3m.
But my local Corgi-registered plumber says that you can't mix horizontal
and vertical flues in this way, and he says Ferroli confirmed this to
him. The only answer would be a new vertical flue system which would
have to pass through the existing flat roof, which I am reluctant to do.

If the boiler will accept either horizontal or vertical flues, why can't
you mix them?

I don't see anything wrong with what you suggest and it would appear that
ferroli don't either: If you take a look at the ferroli website & go to
the
Modena page, then to Flueing, there is a picture of possible
configurations
on the bottom left. The two lowest and leftmost boilers in that picture
have
2x90deg bends with vertical exit (although they don't go above the
roofline)
and second from right in the top storey has 2x45deg bends and goes
through the roof. If 2x90 is indeed off limits, then 2x45 and a slant
opening
in your wall sounds like it would work.

Quite possibly you can do what you suggest but the normal wall type flue
terminal packed in the boiler kit will not be suitable and you will need a
vertical terminal. The proximity to the eaves will be a considerable factor
affecting the suitability so as others said talk to Ferroli and maybe fax
them a dimensioned sketch of your proposal

John wrote:
"fred" wrote in message ...
In article ,
Richard J. writes
In our terraced house, we have a Ferroli Modena 102 combi in the
kitchen, with a horizontal 100mm concentric flue of 0.5m length,
ending on the outside wall which at that point is part of a
single-storey extension to our house. Unfortunately, it's rather
close to next door's kitchen door and patio, and the smell of the
initial exhaust when the boiler starts up is quite noticeable.

According to the manufacturer's manual, the maximum flue length
is 4m, but any bend counts as 1m, so a horizontal flue like mine,
attached to the top of the boiler by a 90deg bend, has a maximum
length of 3m, after the bend.

Fine, I thought, I can add a 90deg bend where the flue emerges
from the wall, and then a 1.5m concentric flue going vertically
upwards to end about half a metre above the top of the wall.
That would be an effective length of 0.5 (existing) + 1 (new
bend) + 1.5 (new flue) = 3m. But my local Corgi-registered
plumber says that you can't mix horizontal and vertical flues in
this way, and he says Ferroli confirmed this to him. The only
answer would be a new vertical flue system which would have to
pass through the existing flat roof, which I am reluctant to do.

If the boiler will accept either horizontal or vertical flues,
why can't you mix them?

I don't see anything wrong with what you suggest and it would
appear that ferroli don't either: [...]

[...] as others said talk to Ferroli and maybe fax them a dimensioned
sketch of your proposal

Thanks for all your advice. I e-mailed Ferroli last night with a sketch
of what I wanted to do, and got a reply this morning saying it *was*
acceptable. Must have been a misunderstanding somewhere when my Corgi
spoke to them.
--
Richard J.
(to e-mail me, swap uk and yon in address)

In article , Richard
J. writes

Thanks for all your advice. I e-mailed Ferroli last night with a sketch
of what I wanted to do, and got a reply this morning saying it *was*
acceptable. Must have been a misunderstanding somewhere when my Corgi
spoke to them.
Good news, thanks for feeding back.
--
fred