Extending a boiler flue
naffer
enclosed a flue from my Ideal Mini C28 boiler, I need to re-route its
existing flue thu' 90deg and up thru' the roof of the new structure.
(Yes, it's a bit of a b*****r to have my new shed full of damp
poisonous fumes :-) I plan to fix it quickly so please don't use the
silly "CORGI" comment, I have University qualifications in relevant
subjects and I ain't daft.)
The present flue pipework is the bog-standard 100mm flue 90deg off the
boiler and straight out thru' the wall. I would like to put a 90deg
bend upwards onto the existing pipe (after removing the terminal
fittings) where it leaves the external wall of the house and extend up
thru' the new roof with appropriate fittings.
The literature from Ideal seems to apply that vertical flues are 125mm
while the horizontal flues are 100mm.
No problem, as such, but this means that I will have to replace the
existing flue all the way right back to the boiler.
So: why are some flues 100mm and others 125mm on the same boiler?
Logically, vertical pipes should vent more easily than horizontal ones
but the diameters are the wrong way round.
Is it about the physical strength of the pipework?
Any bright ideas?
naffer
Ed Sirett
> Having just built a lean-to against my house side wall and thereby
> enclosed a flue from my Ideal Mini C28 boiler, I need to re-route its
> existing flue thu' 90deg and up thru' the roof of the new structure.
>
> (Yes, it's a bit of a b*****r to have my new shed full of damp poisonous
> fumes :-) I plan to fix it quickly so please don't use the silly
> "CORGI" comment, I have University qualifications in relevant subjects
> and I ain't daft.)
>
That makes two of us :-).
> The present flue pipework is the bog-standard 100mm flue 90deg off the
> boiler and straight out thru' the wall. I would like to put a 90deg
> bend upwards onto the existing pipe (after removing the terminal
> fittings) where it leaves the external wall of the house and extend up
> thru' the new roof with appropriate fittings.
>
> The literature from Ideal seems to apply that vertical flues are 125mm
> while the horizontal flues are 100mm.
>
> No problem, as such, but this means that I will have to replace the
> existing flue all the way right back to the boiler.
>
> So: why are some flues 100mm and others 125mm on the same boiler?
> Logically, vertical pipes should vent more easily than horizontal ones
> but the diameters are the wrong way round. Is it about the physical
> strength of the pipework?
>
1) I take it that this boiler is sufficiently young enough to obtain the
correct flue parts, extensions and accessories.
2) You have the installation instructions. I have them and they are
pretty clear. You'll need a vertical flue kit. It's got to be 600mm clear
of the house wall.
I'd reckon that you'll need.
A) Extra 90 elbow. (you should be able to reuse the one currently on the
boiler.).
B) 1m flue extension - this should be enough to go through the wall from
elbow to elbow AND get you 600mm clear of the wall of the house. Unless
you have a house that has walls over 400mm thick.
C) A vertical terminal.
You wont be able to reuse the horizontal flue, which you'll probably
destroy getting it out of the wall.
You might also need to support the flue from the roof of the lean-to.
--
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
YAPH
> Having just built a lean-to against my house side wall and thereby
> enclosed a flue from my Ideal Mini C28 boiler, I need to re-route its
> existing flue thu' 90deg and up thru' the roof of the new structure.
>
> (Yes, it's a bit of a b*****r to have my new shed full of damp
> poisonous fumes :-) I plan to fix it quickly ...
You mean comment that what you've done is illegal, and perhaps suggest
that it might have been better if the horse had preceded the cart? ;-)
> ... so please don't use the silly "CORGI" comment
The illegality is a matter of law, not dictated by CORGI (or Gas Safe
http://yaph.co.uk/CORGI-GasSafe)
> I have University qualifications in relevant subjects ...
A University qualification in Gas Safety would seem to be the relevant
subject. I got mine from Thames Valley University[1]: which University did
you get yours from?
[1] Formerly Reading College, at which the Gas training is still proper Old
School, although like some other post-1992 "Universities" TVU has
succumbed to peddling the sort of courses where a PHD could best be
described as a Patrick Holford Degree :-(
--
John Stumbles -- http://yaph.co.uk
This sig intentionally left blank
naffer
My intention was in saying " no CORGI" was to prevent unthinking
responses which say "you can't do that 'cos u aint CORGI".
Because I can if I can demonstrate that I know what I'm doing then
CORGI is utterly irrelevant.
Anyway, fixing the flue wasn't that hard.
With the help of Ed Sirrett, Ideal's help desk & a jolly chap in Plumb
Center, the job proved to be trivial.
Now it's done & very safely.
**********************
Mind you herewith:
Two CORGI incidents which may give you some sense of why I prefer
intelligence to certificates.
1. Arriving home and hearing from my wife that the CORGI-qualified
man has fixed the non-starting of the boiler.
Yes he had taped down the starter button on the boiler, since it
wouldn't "hold" 'cos the thermocouple was knackered and wouldn't latch
on. Trivial problem to fix but given that there was a pilot light v
serious.
2. CORGI-person who did boiler repair and had to be called backed
since he had not screwed back the cenrifugal fan at the bottom of the
boiler. Four screws, but only one done up and then only finger
tight. Lots of Gas/Air leaking, badly.
"Gosh", he said when called back, "it could have blown your house
up". He thought it was funny.
Fortunately, I was able to call him back because his van just outside
my house, since I could hear the problem, (the gas/air mixture was
escaping thru' the gap he'd left and making a whistling noise),
before he left.
No doubt he was sitting in his van filling in lots of CORGI forms
including ridiculous safety paperwork..
******************************************************
So despite these experiences: I really am not disparaging your
qualifications or practical skills, indeed the fact that you look at
this site and have responded so strongly shows that you take this very
seriously, as I do.
(I really wish you'd been the qualified person in the two events
described above.)
No: of course I have no Gas qualifications but I sincerely respect
those who have,
BUT and it's a big BUT, the the qualifications don't make Gas persons
immune to common-sense. Hence my little comment, "I ain't daft"
naffer
YAPH
> Two CORGI incidents which may give you some sense of why I prefer
> intelligence to certificates.
The ideal situation is both ;-)
> 1. Arriving home and hearing from my wife that the CORGI-qualified
> man has fixed the non-starting of the boiler.
> Yes he had taped down the starter button on the boiler, since it
> wouldn't "hold" 'cos the thermocouple was knackered and wouldn't latch
> on. Trivial problem to fix but given that there was a pilot light v
> serious.
Without checking with my crib sheet (CORGI Gas Industry Unsafe Situations
- or words to that effect - booklet) I'd say that would be notifiable to
HSE under RIDDOR (bypassing safety device).
> 2. CORGI-person who did boiler repair and had to be called backed
> since he had not screwed back the cenrifugal fan at the bottom of the
> boiler. Four screws, but only one done up and then only finger
> tight. Lots of Gas/Air leaking, badly.
If leaking much gas that too could be RIDDOR.
In the first case I'd wonder if the person were genuinely qualified &
registered.
> ******************************************************
> So despite these experiences: I really am not disparaging your
> qualifications or practical skills, indeed the fact that you look at
> this site and have responded so strongly shows that you take this very
> seriously, as I do.
> (I really wish you'd been the qualified person in the two events
> described above.)
None of us is perfect and I've had a couple of instances where I'd left a
leak that was enough to register a smell of gas after a couple of hours.
In both cases I raced back to the job and fixed it, but I couldn't have
complained if they'd got my CORGI inspector onto me to give me a
bollocking. But if I did either of the things you describe I'd seriously
question my own fitness to work in this field.
--
John Stumbles -- http://yaph.co.uk
Hypnotising Hypnotists Can Be Tricky
Ed Sirett
> My I apologise;
> My intention was in saying " no CORGI" was to prevent unthinking
> responses which say "you can't do that 'cos u aint CORGI".
>
> Because I can if I can demonstrate that I know what I'm doing then CORGI
> is utterly irrelevant.
>
> Anyway, fixing the flue wasn't that hard. With the help of Ed Sirrett,
> Ideal's help desk & a jolly chap in Plumb Center, the job proved to be
> trivial. Now it's done & very safely.
> **********************
> Mind you herewith:
>
> Two CORGI incidents which may give you some sense of why I prefer
> intelligence to certificates.
>
> 1. Arriving home and hearing from my wife that the CORGI-qualified man
> has fixed the non-starting of the boiler. Yes he had taped down the
> starter button on the boiler, since it wouldn't "hold" 'cos the
> thermocouple was knackered and wouldn't latch on. Trivial problem to
> fix but given that there was a pilot light v serious.
That would so serous I'd reckon on checking whether the guy was legit or
not.
>
> 2. CORGI-person who did boiler repair and had to be called backed since
> he had not screwed back the cenrifugal fan at the bottom of the boiler.
> Four screws, but only one done up and then only finger tight. Lots of
> Gas/Air leaking, badly.
>
> "Gosh", he said when called back, "it could have blown your house up".
> He thought it was funny.
> Fortunately, I was able to call him back because his van just outside my
> house, since I could hear the problem, (the gas/air mixture was escaping
> thru' the gap he'd left and making a whistling noise), before he left.
> No doubt he was sitting in his van filling in lots of CORGI forms
> including ridiculous safety paperwork..
This was a pre mix burner I presume, also serious. Best not to make this
sort of mistake in the first place.
Given that the boiler was room sealed I doubt you were in any real danger
the worst that would have happened is the boiler would have run very
rich, soot, CO etc.
It is sort of understandable, but not excusable, if you have a lot of
interruptions.
I have CORGI inspector tomorrow (planned visit not a complaint
fortunately).
Tim S
> I have CORGI inspector tomorrow (planned visit not a complaint
> fortunately).
Good luck Ed!
Though I'm sure you don't need it :)
Cheers
Tim
Owain
> I have CORGI inspector tomorrow (planned visit not a complaint
> fortunately).
"You're using the wrong sort of biro on your landlord's forms ... need
to use CORGI approved biros, a snip at 4.99 each..."
Owain