Siting a New (Gas) Boiler
Alan Briggs
My old (oil-fired) boiler is sited in the garage (which is integral to
the house) with a vertical Chimney/flue. I am thinking about replacing
this with a gas boiler, possibly a condensing boiler. The plumber I
consulted seemed to feel it was not possible to site a gas boiler in the
same place and that a short horizontal flue to an outside wall was
required. It seems a shame not to make use of an existing chimney so is
he correct? Could I perhaps use a vertical flue with a fan?
My plumber also said that he had limited experience of condensing
boilers and the general opinion of his brethren was that although these
were heavily pushed by government organisations, their reliability and
lifespan were unproven. Any comments anyone?
--
- Alan Briggs -
Jake
Alan Briggs <Alan.Brig...@nortel.co.uk> wrote in article
<34BA04...@nortel.co.uk>...
> My old (oil-fired) boiler is sited in the garage (which is integral to
> the house) with a vertical Chimney/flue. I am thinking about replacing
> this with a gas boiler, possibly a condensing boiler. The plumber I
> consulted seemed to feel it was not possible to site a gas boiler in the
> same place and that a short horizontal flue to an outside wall was
> required. It seems a shame not to make use of an existing chimney so is
> he correct? Could I perhaps use a vertical flue with a fan?
It's perfectly possible to have a gas boiler with a chimney, we've just
had a combi fitted in this way. There was nowhere to put a balanced
flue boiler so we had to have a conventional flue. The flue goes out the
single-storey roof then has a metal chimney up to above the first
floor windows. Not exactly aesthetically pleasing though.
It does not apply in your case with the boiler in the garage, but we
are regretting not finding some way of fitting a balanced flue
boiler. We now have to have a massive hole in the back door
and so lose all the heat the boiler generates around itself and
have to shut all the doors against the draught.
Gas boilers are not that big, so you may want to consider
putting it in the house.
Jake.
John Laird
In article <34BA04...@nortel.co.uk>, Alan Briggs <Alan.Brig...@nortel.co.uk> writes:
> My old (oil-fired) boiler is sited in the garage (which is integral to
> the house) with a vertical Chimney/flue. I am thinking about replacing
> this with a gas boiler, possibly a condensing boiler. The plumber I
> consulted seemed to feel it was not possible to site a gas boiler in the
> same place and that a short horizontal flue to an outside wall was
> required. It seems a shame not to make use of an existing chimney so is
> he correct? Could I perhaps use a vertical flue with a fan?
>
All in all, I expect you'd have less trouble with the short flue. Modern
boilers, but especially the condensing variety, emit relatively cool waste
gases that simply don't have the oomph to get up any significant length of
vertical pipe. What you don't want is the steam condensing out part-way
up the pipe, causing corrosion and dropping water back down into the boiler.
Any given boiler will have strict specs on suitable flues. How tall is the
existing chimney ? You might also consider that this could well be pretty
gummed up with tarry deposits and a new liner would be the very minimum.
>
> My plumber also said that he had limited experience of condensing
> boilers and the general opinion of his brethren was that although these
> were heavily pushed by government organisations, their reliability and
> lifespan were unproven. Any comments anyone?
>
My plumber said almost exactly the same thing. He did fairly regular work
for local authorities, who stipulated the use of certain makes and types of
boiler, and was not happy with the level of callouts he had to make after
installation to resolve problems with condensing models. I know some people
will suggest that this means no more than that the plumber wasn't good at
his job, or that he was instructed to use unreliable equipment, to which I
can only respond that I had to use my own judgement as to the reliability
of his advice, and that if I had honestly thought that I knew so much better
than him, I would have installed it myself. Imho.
--
John Laird (jo...@yrl.co.uk) "I have discovered a truly elegant sig,
Yezerski Roper Ltd sadly there is no room here to show it."
http://www.yrl.co.uk
Michael Lake
The message <34BA04...@nortel.co.uk>
from Alan Briggs <Alan.Brig...@nortel.co.uk> contains these words:
> My old (oil-fired) boiler is sited in the garage (which is integral to
> the house) with a vertical Chimney/flue. I am thinking about replacing
> this with a gas boiler, possibly a condensing boiler. The plumber I
> consulted seemed to feel it was not possible to site a gas boiler in the
> same place and that a short horizontal flue to an outside wall was
> required. It seems a shame not to make use of an existing chimney so is
> he correct? Could I perhaps use a vertical flue with a fan?
> My plumber also said that he had limited experience of condensing
> boilers and the general opinion of his brethren was that although these
> were heavily pushed by government organisations, their reliability and
> lifespan were unproven. Any comments anyone?
Condensing boilers are very good if installed properly,don't let a
plumber who doesn't know what he is doing install it, as once it's
fitted you will never see him again.
Mick
Whitley Bay
Mike Paley
Put it where you want it ! With the original boiler position, there will be
not much water plumbing to do. Obviously, a gas pipe will have to be
installed from the meter/gas supply. The only other thing is the flue, have
a look at different boilers to see what off the shelf options there are.
Then consider Heath Robinson modifications to suit your requirements and
the boiler's !
E.g. fit the boiler with it's normal flue but duct it into a pipe with a
fan in it or something.
--
Comm again, Mike.
My friend used to go to parties on the moon. He stopped going, so I asked
him why and he replied. "They've got no atmosphere."
Ex Windows 95 user Ex Turnpike user.
More info.: http://www.paley.demon.co.uk/ [1998:01:10]
T1MDownie
>My old (oil-fired) boiler is sited in the garage (which is integral to
>the house) with a vertical Chimney/flue. I am thinking about replacing
>this with a gas boiler, possibly a condensing boiler. The plumber I
>consulted seemed to feel it was not possible to site a gas boiler in the
>same place and that a short horizontal flue to an outside wall was
>required. It seems a shame not to make use of an existing chimney so is
>he correct? Could I perhaps use a vertical flue with a fan?
Most (well nearly all) modern boilers are room sealed so you're going to need a
co-axial flue. While they are available, I think you'll find that it'll be a
lot more expensive than having a balanced flue. We wanted to use our old flue
but the cost was prohibitive.
>My plumber also said that he had limited experience of condensing
>boilers and the general opinion of his brethren was that although these
>were heavily pushed by government organisations, their reliability and
>lifespan were unproven. Any comments anyone?
Yep. We've got an ideal turbo 2 and it has been troublesome. That said,
they're actually less complicated than a combi and there's no reason why they
should be less reliable. We may just have been unlucky. From the economy
point of view, we heat a 5 bedroom cavity wall insulated double glazed, loft
insulated house with a 6 X 4 metre conservatory for about 360 to 420 ukpounds
per annum. Seems reasonable to me.
TD
Roger Chapman
When I replaced my boiler a few years ago I opted for a fan assisted
balanced flue boiler for 3 reasons. Firstly (as someone else has
already mentioned room sealed boilers are safer and lead to less
draughts), secondly the 4" flue is a considerable bonus when you have
2' thick stone walls to contend with and thirdly you have much
greater choice in the length and direction of the flue. Mine exits
sideways with a flue length of about 4' but IIRC I could have used a
much longer flue than that.
Roger
Alan Briggs
Condensing (gas) boilers are supposed to be more efficient but more
expensive than conventional boilers. I would like to do my bit for the
environment by using as little fuel as possible, so I am considering
installing one.
When I consulted my plumber he said that he had limited experience of
condensing boilers and the general opinion of his brethren was that
although these were heavily pushed by government organisations, their
reliability and lifespan were unproven.
I mentioned this in an earlier thread (article
<34BA04...@nortel.co.uk>) and received one reply (from John Laird
jo...@yrl.co.uk) who said he had heard the same thing. I would be
interested in other people's experience or opinions, good or bad.
Roger Chapman
The message <34BDD0...@nortel.co.uk>
from Alan Briggs <Alan.Brig...@nortel.co.uk> contains these words:
> Condensing (gas) boilers are supposed to be more efficient but more
I thought about getting one when I changed my boiler a few years back
but I eventually did not, principally for 2 reasons.
The first that the initial expense is so great that the payback time
would exceed infinity
The second that condensing boilers are *only* more efficient when in
condensing mode which is by no means automatic. IIRC there has to be
a considerably greater than normal temperature drop between inlet and
return for this to occur.
Roger
Ken Hargreaves
Roger Chapman <r.ch...@zetnet.co.uk> wrote in article
<199801151...@zetnet.co.uk>...
> The message <34BDD0...@nortel.co.uk>
> from Alan Briggs <Alan.Brig...@nortel.co.uk> contains these
words:
>
> > Condensing (gas) boilers are supposed to be more efficient but more
> > expensive than conventional boilers. I would like to do my bit for the
> > environment by using as little fuel as possible, so I am considering
> > installing one.
>
> > When I consulted my plumber he said that he had limited experience of
> > condensing boilers and the general opinion of his brethren was that
> > although these were heavily pushed by government organisations, their
> > reliability and lifespan were unproven.
Ours has been completely reliable (tempts fate), but only 14 months so far.
(However, see the previous thread re. explosive ignition and occasional
failure to light). Gas bills are down by about 30%.
>
>
> The first that the initial expense is so great that the payback time
> would exceed infinity
The "official" bumf from the Energy Saving Trust quoted (I think - I'll
check this W/E) 3 to 5 years to payback, based on £400 per year gas bills.
We paid an extra £250 for a condenser compared with a conventional.
>
> The second that condensing boilers are *only* more efficient when in
> condensing mode which is by no means automatic. IIRC there has to be
> a considerably greater than normal temperature drop between inlet and
> return for this to occur.
>
> Roger
>
For what it's worth, I've logged flow and return temperatures on and off
for several months on our system, and while this may not apply to all
installations because it depends on number of radiators, insulation etc.
it's quite instructive:
Starting from cold, the system runs up to 65 deg C return, 75 deg C flow
(maximum possible on our system) and keeps it there (controlled by the
boiler thermostat) until the roomstat shuts the CH down. Thereafter, the
boiler just tops-up the heating on demand from the roomstat and typically,
the return temperature varies between 30 and 40 deg C and the boiler is in
condensing mode (confirmed by collecting the stuff).
In summer, the boiler stat is set lower anyway and return temperature never
exceeds 50 deg C.
Ken.
Richard Gethin
In article <34bf920d...@news.demon.co.uk>, Peter Parry
<pe...@wppltd.demon.co.uk> writes
>
>>The second that condensing boilers are *only* more efficient when in
>>condensing mode which is by no means automatic. IIRC there has to be
>>a considerably greater than normal temperature drop between inlet and
>>return for this to occur.
>
>little differential between input and output temperature - which is
>why they work so well with underfloor heating (and I will never go
>back to radiators having had the joys of underfloor heating!!).
>
Would I be correct in saying that the condensing boiler works well on
your underfloor heating system because lower water temperatures are
used?
I would assume that the return temp has got to be fairly low (anyone got
any figures) to allow the vapour in the fluegas to condense.
Something else I heard about condensing boilers which you all may like
to comment on: because the general temperature of the circulating water
is kept lower you need bigger radiators to maintain room temperatures.
Because of this I would say that a condensing boiler fitted to an
existing system will never be allowed to operate as efficiently as it
might on a new system with radiators designed to run at a lower
temperature.
Discuss.
--
Richard Gethin
T1MDownie
In article <34bf920d...@news.demon.co.uk>, pe...@wppltd.demon.co.uk
(Peter Parry) writes:
>>The second that condensing boilers are *only* more efficient when in
>>condensing mode which is by no means automatic. IIRC there has to be
>>a considerably greater than normal temperature drop between inlet and
>>return for this to occur.
>
>I think you will find its quite the reverse - they work best with
>little differential between input and output temperature - which is
>why they work so well with underfloor heating (and I will never go
>back to radiators having had the joys of underfloor heating!!).
Sorry, but I think the original poster is correct. The reason they work well
with underfloor heating is the relatively much bigger radiating area (and hence
cooler return flow) than with conventionally sized radiators. It is, after
all, the cool return water that reduces the exhaust temperature to below the
dew point that causes the water to condense out of the exhaust.
If you were designing a system from scratch for use with a condensing boiler,
ideally you'd fit "oversize" radiators (or underfloor heating). My own
impression is that mine is still impressively efficient, even with the old
radiators, but I haven't enough data to be certain.
>Ours is an Ideal Turbo 2, [snip]
>If anyone is interested we have the running costs available over a 6
>year period. During this time the boiler has given us no problems
>(he says tempting providence).
Got the same model. Three breakdowns in the first two years. (I think we've
been a tad unlucky)
TD
Andy Wade
Richard Gethin wrote ..
> Would I be correct in saying that the condensing boiler works well on
> your underfloor heating system because lower water temperatures are
> used?
Yes.
> I would assume that the return temp has got to be fairly low (anyone got
> any figures) to allow the vapour in the fluegas to condense.
A "magic number" of 56C is sometimes quoted, but the precise dewpoint
depends on the excess air ratio and in practice is in the range 50 - 55C.
> Something else I heard about condensing boilers which you all may like
> to comment on: because the general temperature of the circulating water
> is kept lower you need bigger radiators to maintain room temperatures.
> Because of this I would say that a condensing boiler fitted to an
> existing system will never be allowed to operate as efficiently as it
> might on a new system with radiators designed to run at a lower
> temperature. > Discuss.
This is true, but does not IMO constitute an argument for not installing a
condensing boiler. That said, one case where the radiators should already
be suitable for lower temperature operation is where insulation had been
significantly improved - e.g. cavity wall insulation installed - since the
system was designed. (There is also the complication that in many existing
systems the radiator sizing will not have been "designed" but rather
"guesstimated" by the installer, introducing a sort of pot-luck error
factor.)
Now I don't profess to be an expert on condensing boilers, but I have
studied the subject a little and certainly intend to install one when the
time comes to replace the lump of cast iron that I've got in the kitchen at
the moment. In particular, there is a CIBSE (Chartered Institute of
Building Services Engineers) publication [1] that I commend to anyone with
a serious interest in this subject. It starts with an introduction to the
fundamental principles and goes on to deal with aspects of boiler design,
system design, controls, and just about everything else you can think of,
all at a reasonably practical level.
I think it is wrong to conclude that it's not worth installing a condensing
boiler unless you can run it in condensing mode almost all the time. In
fact, it will save you fuel even if it never runs in condensing mode,
simply because of the higher efficiency resulting from the larger heat
exchange area. E.g. at full-load and 70C return water temperature [1]
gives median typical efficiency figures of c.78% for a "good modern
conventional boiler" and c.86% for a condenser. At 50C return the
corresponding figures are 79% and 88%. It is important to appreciate that
there isn't a sudden drop in efficiency when the dewpoint is exceeded - the
step change is in the gradient of the efficiency curve, not in the
efficiency itself. To quote some of the conclusions drawn in the CIBSE
manual [1], when considering suitable and unsuitable applications:
"Condensing boilers are particularly suitable for all LTHW heating systems,
both new and replacement, large and small. Their application is not
limited to special warm water systems."
"Optimum applications will be those with high annual heating requirements
..."
"Less favourable applications include buildings with very low design heat
loss, high incidental gains, short intermittent occupancy and short heating
seasons."
"Variable temperature circuits with weather compensation are suitable.
Normal radiator sizing (83C design flow and 72C return temperatures) will
often be the most economic heating circuit option."
"Constant temperature heating circuits are generally unsuitable for
condensing boilers." [I take this to mean systems without weather
compensation.]
A table of typical *seasonal* efficiency figures is given in [1] and makes
interesting reading. Again, to quote verbatim:
Condensing boilers:
- underfloor or warm water system - 90%
- standard size rads, with compensation - 87%
- standard size rads, no compensation, 83/72 flow/return - 85%
Modern high efficiency non-condensing boiler - 80 - 82%
Conventional boilers:
- good modern boiler design closely matched to demand - 75%
- typical good existing boiler - 70%
- typical existing oversized boiler (atmospheric, cast iron, sectional)
55 - 65%.
Sorry to go rambling on for so long. Is anyone still awake? If so, what I
want to learn more about is the relative merits of modulating and on-off
burners (analogue versus digital). Any thoughts on that?
[1] Applications Manual AM3: Condensing Boilers, CIBSE, 1989.
--
Andy
Richard Gethin
In article <01bd23ae$0275d400$LocalHost@dog40>, Andy Wade
<ajw...@dial.pipex.com> writes
>Sorry to go rambling on for so long. Is anyone still awake? If so, what I
>want to learn more about is the relative merits of modulating and on-off
>burners (analogue versus digital). Any thoughts on that?
>
>[1] Applications Manual AM3: Condensing Boilers, CIBSE, 1989.
>
future refence.
--
Richard Gethin
Mike Paley
In article: <01bd23ae$0275d400$LocalHost@dog40> "Andy Wade"
<ajw...@dial.pipex.com> writes:
:) what I
:) want to learn more about is the relative merits of modulating and on-off
:) burners (analogue versus digital). Any thoughts on that?
The world is analogue, so it must be a better system.
A digital boiler will cut in and out to maintain a temperature. i.e
operating gas! valves and heting cooloing the boiler surfaces.
An analogue boiler will settle to a constant heat input as long as it is
withing the permitted range. Not only do you not get on/offs of valves and
switches but the boiler sits there at pretty much a constant temperature.
Anyway, radiators are analogue !
Wookey
In article <lD0XAEAI...@rgethin.demon.co.uk>, Richard Gethin
<URL:mailto:ric...@rgethin.demon.co.uk> wrote:
> I would assume that the return temp has got to be fairly low (anyone got
> any figures) to allow the vapour in the fluegas to condense.
> Something else I heard about condensing boilers which you all may like
> to comment on: because the general temperature of the circulating water
> is kept lower you need bigger radiators to maintain room temperatures.
yes, essentially, although it works the other way round as I understand it.
ie you shoud put bigger rads (oversized by about 15%) in as that increases
the difference between flow and return temps which increases the proportion
of the time in condensing mode. The flow temp is controlled by thermostat
just like a normal boiler, it's the water speed/rad size that determines the
return temp.
> Because of this I would say that a condensing boiler fitted to an
> existing system will never be allowed to operate as efficiently as it
> might on a new system with radiators designed to run at a lower
> temperature.
> Discuss.
I beleive that's correct. I looked into all this when I designed our CH, but
as we were going for a combi and condensing combis were then _really_
expensive (and only just becoming available) I didn't get one. The situation
has probably improved now.
Wookey
--
Aleph One Ltd, Bottisham, CAMBRIDGE, CB5 9BA, UK Tel (00 44) 1223 811679
work: http://www.aleph1.co.uk/ play: http://www.chaos.org.uk/~wookey/
Mike Paley
:) depends on the excess air ratio and in practice is in the range 50-55C.
:)
:) Now I don't profess to be an expert on condensing boilers, but I have
:) studied the subject a little and certainly intend to install one when
:) the time comes to replace the lump of cast iron that I've got in the
:) kitchen at the moment.
That 50 - 55C temperature, is that fluegas temp. or circ. water temp. ?
erm... Now what happens if I run my ordinary combi at 45 - 50C circ. water
temp. ?
Howard Burgess
Mike Paley wrote:
>
> A digital boiler will cut in and out to maintain a temperature. i.e
> operating gas! valves and heting cooloing the boiler surfaces.
>
> An analogue boiler will settle to a constant heat input as long as it is
> withing the permitted range. Not only do you not get on/offs of valves and
> switches but the boiler sits there at pretty much a constant temperature.
My (elementary!) knowledge of thermodynamics would lead me to say that a
boiler will operate most efficiently when it is operating at full load.
Therefore it's more efficient to run a boiler flat-out for (say) 20 mins
than have it is for it to operate at lower power for an hour.
Unfortunately, I can't remember why :)
Howard
--
Lucent Technologies
Roger Chapman
The message <34C6FC9D...@mltsa.remove.uk.lucent.com>
from Howard Burgess <hbur...@mltsa.remove.uk.lucent.com> contains
these words:
> My (elementary!) knowledge of thermodynamics would lead me to say that a
> boiler will operate most efficiently when it is operating at full load.
> Therefore it's more efficient to run a boiler flat-out for (say) 20 mins
> than have it is for it to operate at lower power for an hour.
> Unfortunately, I can't remember why :)
I wouldn't like to comment either way but I have vague memories of
efficiency (for engine cycles) being calculated in terms of
temperature drop over absolute temperature but after so many years I
cannot be sure of the precise context.
Roger
Andy Wade
Mike Paley wrote ...
> "Andy Wade" writes:
> :) A "magic number" of 56C is sometimes quoted, but the precise dewpoint
> :) depends on the excess air ratio and in practice is in the range
50-55C.
> That 50 - 55C temperature, is that fluegas temp. or circ. water temp. ?
Return water temperature.
> erm... Now what happens if I run my ordinary combi at 45 - 50C circ.
water
> temp. ?
Well it won't turn it into a condensing boiler - or at least you hope it
won't. Condensation in non-condensing boilers is generally bad news - see
previous threads on wet ignitors, etc. Condensation shouldn't occur
because the flue gasses remain above the dewpoint under all circumstances.
Condensing boilers have additional heat exchanger surface to cool the
exhaust sufficiently to produce condensation.
--
Andy
Matthew Marks
In article <801269...@paley.demon.co.yuk>,
Mike Paley <mi...@paley.demon.co.yuk> writes:
> The only other thing is the flue, have
> a look at different boilers to see what off the shelf options there are.
> Then consider Heath Robinson modifications to suit your requirements and
> the boiler's !
>
> E.g. fit the boiler with it's normal flue but duct it into a pipe with a
> fan in it or something.
That is the most idiotic piece of advice I have seen in this newsgroup for a
long time.
--
Matthew @rd.bbc.co.uk My opinions, not Auntie's *RETURN ADDRESS SPAMPROOFED*
Mike Paley
In article: <6a9ppr$c...@bbcnews.rd.bbc.co.uk> nob...@rd.bbc.co.uk (Matthew
Marks) writes:
:) > E.g. fit the boiler with it's normal flue but duct it into a pipe with
a
:) > fan in it or something.
:)
:) That is the most idiotic piece of advice I have seen in this newsgroup
for a
:) long time.
:)
Go on then, explain.
Mike Paley
In article: <01bd277b$0b0e7740$LocalHost@8721hvt85436> "Andy Wade"
<AJW...@dial.pipex.com> writes:
:) > erm... Now what happens if I run my ordinary combi at 45 - 50C circ.
:) water
:) > temp. ?
:)
:) Well it won't turn it into a condensing boiler - or at least you hope it
:) won't. Condensation in non-condensing boilers is generally bad news -
see
:) previous threads on wet ignitors, etc. Condensation shouldn't occur
:) because the flue gasses remain above the dewpoint under all
circumstances.
:) Condensing boilers have additional heat exchanger surface to cool the
:) exhaust sufficiently to produce condensation.
:)
The ignition system isn't a problem unless it rains down enough to put the
pilot light out. Maybe I'll just get a wet carpet - no I won't, it's sealed
ain't it !
Oh well ? Anyway, the boiler stat looks like it'll go down to 30C - pretty
useless at that though.
Ian Smith
Heath-Robinson bodges with gas boilers don't seem too clever to me, either.
Matthew was probably rather keen to impress on anyone who doesn't know better
that DIY in relation to boiler flues is potentially a
life-threatening passtime.
Ian.
Mike Paley
In article: <199801241...@zetnet.co.uk> Ian Smith
<ian....@zetnet.co.uk> writes:
:) Heath-Robinson bodges with gas boilers don't seem too clever to me,
either.
:) Matthew was probably rather keen to impress on anyone who doesn't know
better
:) that DIY in relation to boiler flues is potentially a
:) life-threatening passtime.
:)
But I NEVER said do a bodge job ! The boiler needs a supply of fresh air
and the exhaust taking away. Boiler manufacturers are doing it already by
putting fans in the flues. A gas tight flue is essential and so is a fan
failure detector.
Dave
Mike Paley wrote:
>
> In article: <01bd277b$0b0e7740$LocalHost@8721hvt85436> "Andy Wade"
> <AJW...@dial.pipex.com> writes:
> :) > erm... Now what happens if I run my ordinary combi at 45 - 50C circ.
> :) water
> :) > temp. ?
> :)
> :) Well it won't turn it into a condensing boiler - or at least you hope it
> :) won't. Condensation in non-condensing boilers is generally bad news -
> see
> :) previous threads on wet ignitors, etc. Condensation shouldn't occur
> :) because the flue gasses remain above the dewpoint under all
> circumstances.
> :) Condensing boilers have additional heat exchanger surface to cool the
> :) exhaust sufficiently to produce condensation.
> :)
>
> The ignition system isn't a problem unless it rains down enough to put the
> pilot light out. Maybe I'll just get a wet carpet - no I won't, it's sealed
> ain't it !
>
> Oh well ? Anyway, the boiler stat looks like it'll go down to 30C - pretty
> useless at that though.
>
> --
> Comm again, Mike.
I heard that condensed flue vapours can be pretty corrosive which could
lead to serious long term damage in boilers which don't have a drain for
them.
Ian Smith
The message <38221...@paley.demon.co.yuk>
from Mike Paley <mi...@paley.demon.co.yuk> contains these words:
> But I NEVER said do a bodge job ! The boiler needs a supply of fresh air
> and the exhaust taking away. Boiler manufacturers are doing it already by
> putting fans in the flues. A gas tight flue is essential and so is a fan
> failure detector.
Fair enough. Not worth arguing about. However I would personally never
attempt to do myself what boiler manufacturers themselves are hopefully
rather good at. I'm sure that you, Mike, like Matthew would not want to
encourage anyone to get into things that they're not competent to attempt.
And the consequences of filling your house with CO don't bear thinking about.
Ian.
nick nelson
Mike Paley wrote:
>
> But I NEVER said do a bodge job ! The boiler needs a supply of fresh air
> and the exhaust taking away. Boiler manufacturers are doing it already by
> putting fans in the flues. A gas tight flue is essential and so is a fan
> failure detector.
>
Of course, but I think the point was that:
"fit the boiler with it's normal flue but duct it into a pipe with
a fan in it or something"
was rather vague and off-hand, and just might tempt someone who
really had no idea of the dangers, to do something silly.
Take this as an explanation of MM's response rather than
a criticism, I'm always making vague and off-hand remarks
here.
Nick.
Rex Bradley
In article <199801252...@zetnet.co.uk>, Ian Smith
<ian....@zetnet.co.uk> writes
>The message <38221...@paley.demon.co.yuk>
> from Mike Paley <mi...@paley.demon.co.yuk> contains these words:
>
> I'm sure that you, Mike, like Matthew would not want to
>encourage anyone to get into things that they're not competent to attempt.
>And the consequences of filling your house with CO don't bear thinking about.
>
>Ian.
for me.
Stay safe.
--
Arby
Andy Wade
Dave wrote in article ...
> I heard that condensed flue vapours can be pretty corrosive which could
> lead to serious long term damage in boilers which don't have a drain for
> them.
Yes indeed, that's another good reason why you don't want condensation in a
conventional boiler. It's also why all condensing boilers have aluminium
heat exchangers - copper is out because of the problem of it being leached
into the drainage system. The only other suitable material, apparently, is
316 stainless steel, which is too expensive at least for domestic boilers.
Actually, according to the CIBSE manual I referred to in a previous post
the condensate is "only mildly acidic" with a pH in the range 3 - 4.5,
typically 3.5, but of course time and temperature will take their toll even
with that "mild" degree of corrosiveness.
--
Andy
Alan Briggs
Andy Wade wrote:
............
> Yes indeed, that's another good reason why you don't want condensation in a
> conventional boiler. It's also why all condensing boilers have aluminium
> heat exchangers - copper is out because of the problem of it being leached
> into the drainage system. The only other suitable material, apparently, is
> 316 stainless steel, which is too expensive at least for domestic boilers.
Looking at what is currently available on the market I actually find
that many manufacturers do use stainless steel heat exchangers. These
boilers certainly have outputs suitable for domestic use. I have not
yet done a price comparison.
--
- Alan Briggs -
Andy Wade
Alan Briggs wrote ...
> Looking at what is currently available on the market I actually find
> that many manufacturers do use stainless steel heat exchangers. These
> boilers certainly have outputs suitable for domestic use. I have not
> yet done a price comparison.
I stand corrected. Can you name some names?
--
Andy
Andrew Gabriel
In article <38221...@paley.demon.co.yuk>,
Mike Paley <mi...@paley.demon.co.yuk> writes:
>In article: <199801241...@zetnet.co.uk> Ian Smith
><ian....@zetnet.co.uk> writes:
>:) Heath-Robinson bodges with gas boilers don't seem too clever to me,
>either.
>:) Matthew was probably rather keen to impress on anyone who doesn't know
>better
>:) that DIY in relation to boiler flues is potentially a
>:) life-threatening passtime.
>:)
>
>and the exhaust taking away. Boiler manufacturers are doing it already by
>putting fans in the flues. A gas tight flue is essential and so is a fan
>failure detector.
I believe you would have to get the appliance Gas Council approved
again following any such change. That would probably cost you many
times the cost of a replacement appliance designed to cope with
the containt you are attempting to work around.
--
Andrew Gabriel
Consultant Software Engineer
Stephen Dawson
Likewise, what happens when the flue sucks the flame thru said duct and
catches light, ( well it might if he bodges the duct out of mdf )
Matthew Marks wrote in message <6a9ppr$c...@bbcnews.rd.bbc.co.uk>...
>In article <801269...@paley.demon.co.yuk>,
> Mike Paley <mi...@paley.demon.co.yuk> writes:
>> The only other thing is the flue, have
>> a look at different boilers to see what off the shelf options there are.
>> Then consider Heath Robinson modifications to suit your requirements and
>> the boiler's !
>>
>> E.g. fit the boiler with it's normal flue but duct it into a pipe with a
>> fan in it or something.
>
>That is the most idiotic piece of advice I have seen in this newsgroup for
a
Mike Paley
In article: <199801252...@zetnet.co.uk> Ian Smith
:) > But I NEVER said do a bodge job ! The boiler needs a supply of fresh
air
by
:) > putting fans in the flues. A gas tight flue is essential and so is a
fan
:) > failure detector.
:)
:) Fair enough. Not worth arguing about. However I would personally never
:) attempt to do myself what boiler manufacturers themselves are hopefully
:) rather good at. I'm sure that you, Mike, like Matthew would not want to
:) encourage anyone to get into things that they're not competent to
attempt.
:) And the consequences of filling your house with CO don't bear thinking
about.
:)
It's a case of being competent enough to know your own competence level for
a particular task.
Unfortunately, I'm not sure of my competence to take the car back to the
garage and competently complain that they've done a bodge job of fitting my
exhaust. Both new joints leak, one badly and at least the tail pipe has
mountings missing !
Mike Paley
In article: <01bd2a55$85ce04a0$LocalHost@8721hvt85436> "Andy Wade"
<AJW...@dial.pipex.com> writes:
:) Yes indeed, that's another good reason why you don't want condensation
in a
:) conventional boiler. It's also why all condensing boilers have
aluminium
:) heat exchangers - copper is out because of the problem of it being
leached
:) into the drainage system. The only other suitable material, apparently,
is
:) 316 stainless steel, which is too expensive at least for domestic
boilers.
:)
I'd have though allyminium would be worse as it's more reactive. But it's
chemistry - and that's where I shut up !
Mike Paley
In article: <34CCB8...@education.leeds.ac.uk>
n.w.n...@education.leeds.ac.uk (nick nelson) writes:
:) Mike Paley wrote:
:)
:) >
air
:) > and the exhaust taking away. Boiler manufacturers are doing it already
by
:) > putting fans in the flues. A gas tight flue is essential and so is a
fan
:) > failure detector.
:) >
:)
:)
:) "fit the boiler with it's normal flue but duct it into a pipe with
:) a fan in it or something"
:)
:) was rather vague and off-hand, and just might tempt someone who
:) really had no idea of the dangers, to do something silly.
:)
:) Take this as an explanation of MM's response rather than
:) a criticism, I'm always making vague and off-hand remarks
:) here.
:)
Come on be truthful !!! I'm an incompetent Usenet user ! - for not taking
into account WHO may take the "advice" and....
Mike Paley
In article: <TpI7qTA+$Gz0...@brad.demon.co.uk> Rex Bradley
<br...@brad.demon.co.uk> writes:
:) > I'm sure that you, Mike, like Matthew would not want to
:) >encourage anyone to get into things that they're not competent to
attempt.
:) >And the consequences of filling your house with CO don't bear thinking
about.
:) >
:) >Here here, one funeral of a young student who died this way is enough
:) for me.
:)
:) Stay safe.
:)
I went to a new friend's house a while back. It wasn't long before I got a
"sleepsafe" CO detector. Ok, CO is smellless(!) but there was a "paraffiny"
smell - from a gas cooker !
Alan Briggs
Viessman, Yorkstar (I'm told), Atlantic 2000, Eco
Broag,
Ferroli use copper (primary) and aluminium secondary
Alan Briggs
Sorry about the previous posting. A software glitch caused the message
to be sent before I had finished composing it!
Andy Wade wrote:
>
> Alan Briggs wrote ...
>
> > Looking at what is currently available on the market I actually find
> > that many manufacturers do use stainless steel heat exchangers. These
> > boilers certainly have outputs suitable for domestic use. I have not
> > yet done a price comparison.
>
> I stand corrected. Can you name some names?
>
> --
> Andy
At present the Energy Saving Trust (government sponsored organisation)
is offering a £200 cashback on condensing boilers from a list of
approved suppliers. From the suppliers on this list:
Atlantic 2000, Eco Hometec, Vaillant and Viessman use stainless steel
heat exchangers. Yorkpark told me they do and I think Keston do also.
Broag and Potterton use Aluminium.
Ferroli use copper (primary) and aluminium (secondary). Vokera use
"cast alloy".
There are a number of other manufacturers but I don't have their details
to hand. The recommended retail proce of the Potterton boiler is not
significantly lower than that of at least some of those with stainless
steel heat exchangers.
()
On Fri, 23 Jan 1998 21:42:44 , Mike Paley <mi...@paley.demon.co.yuk>
wrote:
>In article: <6a9ppr$c...@bbcnews.rd.bbc.co.uk> nob...@rd.bbc.co.uk (Matthew
>Marks) writes:
>:) > E.g. fit the boiler with it's normal flue but duct it into a pipe with
>a
>:) > fan in it or something.
>:)
>:) That is the most idiotic piece of advice I have seen in this newsgroup
>for a
>:) long time.
>:)
>
>Go on then, explain.
>
>--
>Comm again, Mike.
>
>My friend used to go to parties on the moon. He stopped going, so I asked
>him why and he replied. "They've got no atmosphere."
>
>Ex Windows 95 user Ex Turnpike user.
>
>More info.: http://www.paley.demon.co.uk/ [1998:01:10]
>
>
>
>
Well of course you can fan a conventional flue. It is a common place
arrangement in large commercial and industrial setups where single
large or smaller modular boilers are used. It is very rarely used in a
domestic setup though instances can be found. A "flue booster" unit is
fitted in the conventional flue and a flow switch is incorporated to
ensure that if the fan fails,the burner stays off. Similar fan units
can be fitted to chimney pots etc. Agreed it is less than ideal as it
doesnt help boiler efficiency.Far better to install something more
suitable for the situation....
Jon Rouse
Mike Paley wrote:
>
> Unfortunately, I'm not sure of my competence to take the car back to the
> garage and competently complain that they've done a bodge job of fitting my
> exhaust. Both new joints leak, one badly and at least the tail pipe has
> mountings missing !
If the garage is one of a chain, go to another garage in the chain and say 'My
exhaust seems a bit dodgy - can you fix it'.
Then, when presented with the bill, produce your receipt from the other garage
and tell them to claim from them.
--
The views expressed are my own and may not represent those of my employer.
Matthew Marks
In article <296439...@paley.demon.co.yuk>,
Mike Paley <mi...@paley.demon.co.yuk> writes:
> In article: <6a9ppr$c...@bbcnews.rd.bbc.co.uk> nob...@rd.bbc.co.uk (Matthew
> Marks) writes:
>:) > E.g. fit the boiler with it's normal flue but duct it into a pipe with
> a
>:) > fan in it or something.
>:)
>:) That is the most idiotic piece of advice I have seen in this newsgroup
> for a
>:) long time.
>:)
>
> Go on then, explain.
Thank you to others who have correctly guessed my worries in my absence from
this thread. Making throw-away remarks like that, with no mention of fan
failure detectors, etc, might just encourage someone without sufficient
knowledge (like MOST of us when it comes to gas flues) to take your advice
literally, and create a very dangerous installation. As has also been pointed
out, they might not know about it because of the nature of carbon monoxide.
Matthew Marks
In article <348110...@paley.demon.co.yuk>,
Mike Paley <mi...@paley.demon.co.yuk> writes:
>
> I'd have though allyminium would be worse as it's more reactive. But it's
> chemistry - and that's where I shut up !
I thought the point about Al was its oxide (see welding thread) which is
impermeable and very non-reactive. It forms pretty instantly and protects
the metal underneath.
Matthew Marks
In article <34CD9D...@nortel.co.uk>,
Alan Briggs <Alan.Brig...@nortel.co.uk> writes:
> At present the Energy Saving Trust (government sponsored organisation)
> approved suppliers.
But isn't taht only if the boiler's fitted professionally, thereby neatly
wiping out the saving? (CORGI police: please keep quiet.)
Andy Wade
Matthew Marks wrote ...
> But isn't taht only if the boiler's fitted professionally, thereby neatly
> wiping out the saving?
That was my understanding too.
> (CORGI police: please keep quiet.)
It's perfectly legal provided that you are "competent", but don't let's
start that thread again.
--
Andy
Nick Lusty
That is what it says in the leaflet says. And it must be fitted before
the end of this month. Where is a good place to go to for condensing
boilers - how much would a 80,000 BTU output boiler resonably cost?
Would you recommend one?
Andy Wade wrote:
> That was my understanding too.
Matthew Marks wrote ...
> Ł200 refund is only if the boiler's fitted professionally, thereby