Relative lives in an inner, three story town house and needs a new
boiler. The current ~20 year old boiler is located on the ground floor
with the flue running up through the other two (concrete) floors.
There's a garage to the front and a kitchen to the rear and the boiler
is in a walk-in cupboard between the two.

She's been told that the boiler must go on an outside wall with the flue
through the wall, or on the top floor with the flue through the flat
roof. Question is, why can't it go where the existing boiler is? Is
there a limit on the length of flues for modern boilers?

--
F

(Beware of spam trap - remove the negative)

In article , F
writes
Relative lives in an inner, three story town house and needs a new
boiler. The current ~20 year old boiler is located on the ground floor
with the flue running up through the other two (concrete) floors.
There's a garage to the front and a kitchen to the rear and the boiler
is in a walk-in cupboard between the two.

She's been told that the boiler must go on an outside wall with the flue
through the wall, or on the top floor with the flue through the flat
roof. Question is, why can't it go where the existing boiler is? Is
there a limit on the length of flues for modern boilers?

It t' old days this was not a problem as a conventionally flued boiler
could draw air from the room in which it was sited and the exhaust gas
was so hot that it could easily find its way up a long large bore flue
to the top of house.

Nowadays it is not considered safe for new installations to draw air
from the room in the appliance is sited and the regulated requirement
for condensing boilers having low exhaust temperatures means that the
flue gasses no longer have the oomf to make it up a long flue on their
own.

The solution is fan assisted balanced flues which are frequently
concentric (exhaust inside and inlet outside) and although extension
pieces are available they are expensive and there is a limit on the
length that the fan can suck and push the gasses.

Boilers do exist that are capable of driving long flues but this is a
specialist requirement so there aren't that many around and some of them
are expensive. Almost universally they split the flue into 2 pipes to
drive long distances. I know of:

Keston - Reasonably priced boilers, and flues are formed from low cost
(but inflexible) 50mm muPVC drainpipe. I have a Keston Celsius 25 boiler
but I'm not sure I would give it an unqualified recommendation

Mann Micromat - A top quality German boiler but pricey, extension flue
is flexible corrugated plastic tube which is cheaper than metal
extension but still expensive for long runs. Formerly distributed by Eco
Hometec but I've lost track of who are doing them now.

Ariston - Saw these in a block of flats a while back and noticed they
were using long flues via adaptors, no detailed info.

To cut a long story short, if you chose to go the long flue route then
you will be making life more difficult for yourself, you will be paying
more and tying yourself to a number of specialist suppliers whose
support network may not be as extensive as the mainstream market and as
a result you may have difficulty with spares in the future.

More mainstream boilers are most easily fitted to outside walls but many
can drive concentric flues of 3 or 4m which may mean that you can fit
them in a cupboard and route the flue to the outside.

See also the group boiler choice faq from Ed Sirett:
http://www.makewrite.demon.co.uk/BoilerChoice.html
--
fred
Plusnet - I hope you like vanilla

On 23/12/2007 13:39 fred wrote:

More mainstream boilers are most easily fitted to outside walls but many
can drive concentric flues of 3 or 4m which may mean that you can fit
them in a cupboard and route the flue to the outside.

Thanks for that. The alternative horizontal flue through the wall into
the garage and then out above the garage door was one that I had thought
of but, for some unfathomable reason didn't go down too well with her.

--
F

(Beware of spam trap - remove the negative)

"F" wrote in message
...
On 23/12/2007 13:39 fred wrote:

More mainstream boilers are most easily fitted to outside walls but many
can drive concentric flues of 3 or 4m which may mean that you can fit
them in a cupboard and route the flue to the outside.

Using twin pipes (plastic drain around 2" pipe) 30 foot and more.

Thanks for that. The alternative horizontal flue through the wall into the
garage and then out above the garage door was one that I had thought of
but, for some unfathomable reason didn't go down too well with her.

In article ,
fred writes:
Keston - Reasonably priced boilers, and flues are formed from low cost
(but inflexible) 50mm muPVC drainpipe. I have a Keston Celsius 25 boiler
but I'm not sure I would give it an unqualified recommendation

I ordered a set of servicing spares for mine a few weeks ago
thinking they might arrive by end of March when its service
is due, and unlike my previous experiences, every part was in
stock and arrived next day.

BTW, Keston stopped making the C25 over a year ago, although
I have seen stock still for sale quite recently.

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

On Sun, 23 Dec 2007 16:14:31 +0000, Andrew Gabriel wrote:

In article ,
fred writes:
Keston - Reasonably priced boilers, and flues are formed from low cost
(but inflexible) 50mm muPVC drainpipe. I have a Keston Celsius 25
boiler but I'm not sure I would give it an unqualified recommendation

I ordered a set of servicing spares for mine a few weeks ago thinking
they might arrive by end of March when its service is due, and unlike my
previous experiences, every part was in stock and arrived next day.

BTW, Keston stopped making the C25 over a year ago, although I have seen
stock still for sale quite recently.

Presumably they will be bringing out a replacement model in their range?


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

In article , Ed Sirett
writes
On Sun, 23 Dec 2007 16:14:31 +0000, Andrew Gabriel wrote:

In article ,
fred writes:
Keston - Reasonably priced boilers, and flues are formed from low cost
(but inflexible) 50mm muPVC drainpipe. I have a Keston Celsius 25
boiler but I'm not sure I would give it an unqualified recommendation

I ordered a set of servicing spares for mine a few weeks ago thinking
they might arrive by end of March when its service is due, and unlike my
previous experiences, every part was in stock and arrived next day.

BTW, Keston stopped making the C25 over a year ago, although I have seen
stock still for sale quite recently.

Presumably they will be bringing out a replacement model in their range?

Andy had me worried there for a minute but it looks like they have
introduced the Qudos 28 as a mid level domestic replacement that fixes
some of the original issues I had with the Celsius 25. There are
separate control temperatures depending on the demand source with
thermistor sensor modulated control of DHW temp and they promise
compatibility with low grade heat from solar panels in the future. Full
list is: Room Compensation, Weather Compensation, Solar Control,
Modulating DHW Reheat, Solar Thermal, Analog Demand (0-10VDC), External
Lockout Signal, Remote Fascia Panel plus LCD control panel and display
of system params (flue temp, flow/return temp, other temp densors) in
installer mode. They've retained the 20m/50mm maximum flue length and
even extended it to 60m when increased to 65mm. Suffix H is heat only
without pump or expansion vessel, suffix S is a system unit with those
parts incorporated.

£722.08 and £788.13 inc vat for the 'H' & 'S' respectively at
discountedheating.

I'm quietly impressed.
--
fred
Plusnet - I hope you like vanilla

"fred" wrote in message ...
In article , Ed Sirett
writes
On Sun, 23 Dec 2007 16:14:31 +0000, Andrew Gabriel wrote:

In article ,
fred writes:
Keston - Reasonably priced boilers, and flues are formed from low cost
(but inflexible) 50mm muPVC drainpipe. I have a Keston Celsius 25
boiler but I'm not sure I would give it an unqualified recommendation

I ordered a set of servicing spares for mine a few weeks ago thinking
they might arrive by end of March when its service is due, and unlike my
previous experiences, every part was in stock and arrived next day.

BTW, Keston stopped making the C25 over a year ago, although I have seen
stock still for sale quite recently.

Presumably they will be bringing out a replacement model in their range?

Andy had me worried there for a minute but it looks like they have
introduced the Qudos 28 as a mid level domestic replacement that fixes
some of the original issues I had with the Celsius 25. There are separate
control temperatures depending on the demand source with thermistor sensor
modulated control of DHW temp and they promise compatibility with low
grade heat from solar panels in the future. Full list is: Room
Compensation, Weather Compensation, Solar Control, Modulating DHW Reheat,
Solar Thermal, Analog Demand (0-10VDC), External Lockout Signal, Remote
Fascia Panel plus LCD control panel and display of system params (flue
temp, flow/return temp, other temp densors) in installer mode. They've
retained the 20m/50mm maximum flue length and even extended it to 60m when
increased to 65mm. Suffix H is heat only without pump or expansion vessel,
suffix S is a system unit with those parts incorporated.

£722.08 and £788.13 inc vat for the 'H' & 'S' respectively at
discountedheating.

I'm quietly impressed.

The Qudos 28 has a spiral tube stainless steel heat exchanger top mounted
burner design. They went back to their original designs. The Celsius by the
time they dropped it had all it problems ironed out. A late model Celsius
is good buy.

The Qudos is well priced for what it is.

On Sun, 23 Dec 2007 19:10:40 +0000, fred wrote:

In article , Ed Sirett
writes
On Sun, 23 Dec 2007 16:14:31 +0000, Andrew Gabriel wrote:

In article ,
fred writes:
Keston - Reasonably priced boilers, and flues are formed from low
cost (but inflexible) 50mm muPVC drainpipe. I have a Keston Celsius
25 boiler but I'm not sure I would give it an unqualified
recommendation

I ordered a set of servicing spares for mine a few weeks ago thinking
they might arrive by end of March when its service is due, and unlike
my previous experiences, every part was in stock and arrived next day.

BTW, Keston stopped making the C25 over a year ago, although I have
seen stock still for sale quite recently.

Presumably they will be bringing out a replacement model in their range?

Andy had me worried there for a minute but it looks like they have
introduced the Qudos 28 as a mid level domestic replacement that fixes
some of the original issues I had with the Celsius 25. There are
separate control temperatures depending on the demand source with
thermistor sensor modulated control of DHW temp and they promise
compatibility with low grade heat from solar panels in the future. Full
list is: Room Compensation, Weather Compensation, Solar Control,
Modulating DHW Reheat, Solar Thermal, Analog Demand (0-10VDC), External
Lockout Signal, Remote Fascia Panel plus LCD control panel and display
of system params (flue temp, flow/return temp, other temp densors) in
installer mode. They've retained the 20m/50mm maximum flue length and
even extended it to 60m when increased to 65mm. Suffix H is heat only
without pump or expansion vessel, suffix S is a system unit with those
parts incorporated.

£722.08 and £788.13 inc vat for the 'H' & 'S' respectively at
discountedheating.

I'm quietly impressed.

This boiler would have the most sophosticated controls of any in that
price bracket.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

"fred" wrote in message ...

Andy had me worried there for a minute but it looks like they have
introduced the Qudos 28 as a mid level domestic replacement that fixes
some of the original issues I had with the Celsius 25. There are separate
control temperatures depending on the demand source with thermistor sensor
modulated control of DHW temp and they promise compatibility with low
grade heat from solar panels in the future. Full list is: Room
Compensation, Weather Compensation, Solar Control, Modulating DHW Reheat,
Solar Thermal, Analog Demand (0-10VDC), External Lockout Signal, Remote
Fascia Panel plus LCD control panel and display of system params (flue
temp, flow/return temp, other temp densors) in installer mode. They've
retained the 20m/50mm maximum flue length and even extended it to 60m when
increased to 65mm. Suffix H is heat only without pump or expansion vessel,
suffix S is a system unit with those parts incorporated.

£722.08 and £788.13 inc vat for the 'H' & 'S' respectively at
discountedheating.

I'm quietly impressed.

The C55 (55 kW) is £1821. Two Qudos 28 kW boilers is £1576. ...and a back
up boiler in case. With the right boioper sequence controller this will
modulate from about 6kW to £56 kW.

F wrote:
Relative lives in an inner, three story town house and needs a new
boiler. The current ~20 year old boiler is located on the ground floor
with the flue running up through the other two (concrete) floors.
There's a garage to the front and a kitchen to the rear and the boiler
is in a walk-in cupboard between the two.

She's been told that the boiler must go on an outside wall with the flue
through the wall, or on the top floor with the flue through the flat
roof.

That sounds like ******** to me.

Question is, why can't it go where the existing boiler is? Is
there a limit on the length of flues for modern boilers?


May be an issue with condensing types. Dunno.

My guess is that otherwise water drips down the flue pipe or summat.

On Sun, 23 Dec 2007 13:55:42 +0000, The Natural Philosopher wrote:

F wrote:
Relative lives in an inner, three story town house and needs a new
boiler. The current ~20 year old boiler is located on the ground floor
with the flue running up through the other two (concrete) floors.
There's a garage to the front and a kitchen to the rear and the boiler
is in a walk-in cupboard between the two.

She's been told that the boiler must go on an outside wall with the
flue through the wall, or on the top floor with the flue through the
flat roof.

That sounds like ******** to me.

Agreed, except for cost issues about the length of flue components etc.


Question is, why can't it go where the existing boiler is? Is there a
limit on the length of flues for modern boilers?

Varies from maker to make but invariably they are all competing with each
other to make things as long and as versatile as possible.



May be an issue with condensing types. Dunno.

One of the make requires a drain+trap at the base of vertical sections of
above a certain height.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

"F" wrote in message
...
Relative lives in an inner, three story town house and needs a new boiler.
The current ~20 year old boiler is located on the ground floor with the
flue running up through the other two (concrete) floors. There's a garage
to the front and a kitchen to the rear and the boiler is in a walk-in
cupboard between the two.

She's been told that the boiler must go on an outside wall with the flue
through the wall, or on the top floor with the flue through the flat roof.
Question is, why can't it go where the existing boiler is? Is there a
limit on the length of flues for modern boilers?

A boiler can go in the loft, flued through the roof.

On 23/12/2007 19:21 Doctor Drivel wrote:

A boiler can go in the loft, flued through the roof.

She doesn't have a loft, just a top floor.

However, my neighbour has had a boiler installed in her loft. It went
AWOL after a few months, BG came out to fix it (the original fitter
couldn't get out to it and there were young children in a very cold
house) and the guy refused to go up into the loft. Elf and safety! He
was persuaded to change his mind when said neighbour asked him what his
supervisor would say when he smelled the alcohol on his breath!

--
F

(Beware of spam trap - remove the negative)

"F" wrote in message
...
On 23/12/2007 19:21 Doctor Drivel wrote:

A boiler can go in the loft, flued through the roof.

She doesn't have a loft, just a top floor.

However, my neighbour has had a boiler installed in her loft. It went AWOL
after a few months, BG came out to fix it (the original fitter couldn't
get out to it and there were young children in a very cold house) and the
guy refused to go up into the loft. Elf and safety! He was persuaded to
change his mind when said neighbour asked him what his supervisor would
say when he smelled the alcohol on his breath!

Must be boarded from hatch to boiler. A permanent light, and a shoot down
ladder. Then he can't refuse.

"F" wrote in message
...
Relative lives in an inner, three story town house and needs a new boiler.
The current ~20 year old boiler is located on the ground floor with the
flue running up through the other two (concrete) floors. There's a garage
to the front and a kitchen to the rear and the boiler is in a walk-in
cupboard between the two.

She's been told that the boiler must go on an outside wall with the flue
through the wall, or on the top floor with the flue through the flat roof.
Question is, why can't it go where the existing boiler is? Is there a
limit on the length of flues for modern boilers?

Look at:
http://www.keston.co.uk/downloads/ma...tions-Q28S.pdf

Long flue lengths using plastic drain pipe.

Brilliant thread, it will help me choose a new boiler/ controller in the
spring.

I had a Camray 70/90 Oil boiler in my previous house controlled by a
Honeywell AQ6000, a brilliant controller unfortunately no longer made. I
installed and commissioned it in August 1996, never had any problems with
the boiler or controller and AFAIAA the new owners (4Yrs) have had good
service from it.
However, new technology, we must move on, am looking forward to getting to
grips with it.

Regards
Don