On 30 Aug 2005 03:52:30 -0700, "mmccar"
wrote:
I had British Gas around last week to see if I could replace my
existing wall mounted boiler in the kitchen with a combi, allowing me
to ditch the ShowerMax in the bathroom. They informed me that as of
April this year, all new Combi's must be condensing, which require a
22mm feed. Unfortunately, my existing boiler has a 15mm feed, the 22mm
feed into the house, post meter, drops into the concrete floor in the
garage and at some stage before popping out the wall in the kitchen
changes to 15mm.
Not quite. All new gas boilers must be condensing, unless you qualify
under the points system not to have one.
So it looks like I have two options, either:
a) Replace boiler in same position - will require digging up of
concrete ground floor to locate the start of the 15mm pipe.
You are going to have to do something about the gas supply anyway. the
issue is the gas rate required by the combi - it is not an issue of
condensing or not. Perhaps it is possible to do this with running a
new pipe other than through the floor?
b) Move boiler to garage - will require lifting of upstairs' floor
to redirect pipe work from bathroom.
I believe both options will require a vertical extended flue over 2m,
as distance of the existing/new horizontal flue terminal to
neighbouring boundary is/would be 2.5m.
Using the 'Guide to the Condensing Boiler Installation Assessment
Procedure for Dwellings'
(http://www.odpm.gov.uk/stellent/grou...reg_037022.pdf)
I calculated the 'cost' of these options to be:
a) Detached 590 + Extended flue 200 = 790
b) Detached 590 + New boiler position 350 + Extended flue 200 = 1140
Option a) would apply since it is possible to install in the existing
position. For the purpose of the assessment, the lowest scored option
is used. If you choose to re-site, that is your choice - you can't
use it to increase the points as you suggest in option (b)
Now, the guide states:
"It should be noted that when considering boiler locations for the
purposes of the assessment procedure, obstacles such as furniture and
fitments must be ignored."
My question is: Is my concrete ground floor considered as furniture or
fitments? i.e. would the relocation to the garage be considered the
"only feasible" option and with a cost 1000 would this mean I
would qualify for a non-condensing boiler?
It doesn't make any difference.
I can't believe that the government expects anyone requiring a new
boiler to have to replace it with a condensing boiler at any
'monetary cost' because the 'assessment cost' is below 1000.
We live in a nanny state. This is what people voted for.
To add to the confusion, the British Gas guy was unaware of the new
2.5m minimum distance rule and still believed it to by 0.6m, he even
checked the documentation on his laptop, which he informed me, made no
reference to the new distance. This is a little worrying considering
British Gas have been fitting condensing boilers under the new
regulations for several months now.
He is looking at the safety requirement which is 0.6m. The other is
only to avoid potential nuisance to the neighbour from a possible
plume. With a very long flue, it is quite likely that there would
not be significant pluming anyway because much of the water vapour
would condense and run back to the boiler.
He also said they could fit a
plume divertor terminal if it was going to be an issue, however, I
believe this would still be too close to my property boundary?
Two things here.
Look at other suppliers as well as BG and you will discover that they
are charging much more than most independent heating engineers - often
up to twice as much.
You could look at a boiler which will take twin plastic flues. Quite
a number have this as an option and they are implemented using 50mm
muPVC high temperature waste pipe. This gives a much neater and
cheaper solution for long runs, especially if you have to have some
gymnastics with the routing.
Any expert advice would be greatly appreciated as I am looking at
having to layout £3500 if I am forced to go down the condensing combi
route.
It should be possible to do this for under £2000. If you choose an
independent installer. Much of the work will be with running a new
gas service which you'll need anyway and a new flue. The difference
in boiler cost is not going to be great in the equation, so you might
as well have a condensing product and save on gas as well. Roughly
speaking the comparison is between 80% vs 90% seasonal efficiency so
you should be able to achieve a payback within the lifetime of the
boiler.
--
..andy
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