"mmccar" wrote in message
ups.com...
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.

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.

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

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?

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.

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 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?

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.

Not too sure about the distance of the flue to the boundary: the problem
with
condensing combis is that they put out large clouds of steam on some days as
the exhaust is so cool, and that would constitute a nuisance to a neighbour.
If the
BG man can deflect the existing flue upward perhaps this will be ok, AKAIK
the
issue of distance to boundary oly really applies for sideways facing flues.
You can
dig the relevant regulations up on the web, some of the combi manufacturers
have
them as .pdf files on their websites.
As for the gas pipe, then if you are fitting a combi that is much more
powerful
than your existing boiler ( a typical combi might be 28kW, I don't know what
power your existing boiler is ), then the feed pipe by rule of thumb needs
to be
22mm to within 1metre of the combi, then 15mm is allowable for the last
meter.
The reason is the pressure drop will be far too great if you use 15mm pipe
for
the combi to work within specification. There are calculator websites
available
on the web to help you work out the actual pressure drop, but certainly 15mm
will not do.

Andy.