Chistian,

Thanks for the info.

On Fri, 17 Jun 2005 16:34:30 +0100, "Christian McArdle"
wrote:

1. it is against the law to not fit condensing boilers now.
From other postings this would seem true.

Well, there are exceptions, but these are unlikely to apply to you,.

So I gather. It would be really difficult to argue in my case.

2. They would remove the room thermostat as it was bad to have it in a
room where radiators have TRVs.
Other posts to this group seem to suggest having a room thermo is OK
but not to have TRVs in the same room.

You need a "boiler interlock" that completely turns off the boiler when the
house is hot. Normally this is supplied by the room thermostat. If there is
none, another method must be used, such as a flow switch on the heating
circuit. Did the installer indicate how boiler interlock was intended to be
achieved?

Not that I recall. A question I'll ask of him.

3. When I said I wasn't sure if we had a bypass and if we went all
TRVs I thought we'd need one he said all their condensing boilers come
with a built in bypass.

Without knowing all the boilers they supply, it isn't possible to say. Some
boilers have internal bypass, some don't. However, there's no reason to
disbelieve, really. You'd need one even without all TRV, as you are going
S-Plan.

4. Regarding placement on the boiler he said manufacturer specs said
their must be at least 600mm space in front of the boiler although it
was OK in a cupboard so long as with the doors open their was 600mm in
front. As a result he suggested installing it around the corner from
where it is now.

Sounds normal, assuming the move around the corner is to improve aesthetics,
or flue location.

Actually moving it round the corner increases flue length. The problem
occurs because the current boiler is on an end wall right up to a
boxed vertical section carrying the soil pipe, other pipes and pump.
On the other side of the corner my wife wants two double wardrobes and
if the boiler was replaced in the current position there would only be
29cm space in front of the bolier. He suggested putting the boiler on
the wall to carry the wardrobes inside one of them. I assumed the
corner flue piece he quoted for was to take the flue round to the
existing flue exit hole which is why I was also questioning the
"specialist building work".

6. condensate from new boiler was not a problem since the boiler will
be sited next to a soil pipe.

Sounds good. Better than some where they use a "soak away", which is a
euphemism for sticking a bare pipe out of the wall which rots away your
patio.

7. our system was wrong be cause there is not at least 1.5m between
the top of the boiler and where the pipes go into the cylinder. This
would cause our boiler to switch on and off alot when only heating hot
water.

The vertical height of the boiler and cylinder is no longer relevent, as the
system MUST be converted to fully pumped by law. Fully pumped systems don't
care about heights.

He didn't explain it must be converted to fully pumped he made it
sound like our system was wrong and the new one would overcome this
error.

8. conversion from gravity fed to fully pumped was a time consuming
process. Some sort of air valve would have to be installed - I'm not
sure exactly about this. The system would have to be fully pumped
which mean installation ot 2 new valves and pump.

There are other methods, but the 2 valves and the pump is one of the most
common, simplest and reliable. It is called 'S' Plan. Some of the conversion
will be to make it a sealed pressurised system, rather than gravity fed.
This is well worth doing.

I think this is where this "air vent thingy" come in - it was
something to do with keeping our system open. He definitely said they
would not be converting it to sealed system because some of the
pipework is in concrete and a leak would be a big problem.

9. It was around 3 days work.

Could well be.

10. the quote left has a "the effects of pluming have been explained"
but they never were.

The exhaust terminal will shoot out loads of visible steam, especially in
winter. This may seriously annoy the neighbours, even though the exhaust is
actually cleaner and less poisonous that the invisible plume of older
boilers.

"shoot out" does not sound so good. It is less than 3' to a fence and
then less than 3' to my neighbours house with the fence lower than the
vent. Shooting out whilst someone is walking down the side of the
house (either on my side or my neighbours) wouldn't be good.

11. He criticised the current electrical installation a lot. Wrong
cable used throughout - should all be flex

There is no need for the cabling to be flex. Indeed, apart from the final
connections to any immersion heaters, external pumps or zone valves, fixed
T&E wiring is actually superior. Flex is often used because it is easy to
get multicore versions which are more convenient, though.

The valve behind the cylinder is connected to a junction box by T&E.
From here 2 T&E come down to another juntion box where flex goes off
to the boiler and programmer. The immersion heater is flex. It was the
T&E down the boxed section from my airing cupboard to the jn box below
he specifically tutted at.

- and told me a horror story about a house fire near us caused by
wrong electrical installation where the insurers were not fully
paying out after identifying sub standard electrical fitment of
halogen lighting.

Ignore friend of a friend horror stories. Almost certainly not true.

12. When I asked how he would calculate what size of boiler we'd need
he said he didn't need to as it would be a modulating condensing
boiler which constantly monitors the exit and return water temperature
and adjusts automatically. I did not think this was a satisfactory
answer since clearly if he fitted a 1KW boiler it would not sufficient
(absurd example I know).

He is actually correct. Most modern condensing boilers have a much greater
maximum output than any normal house requires. (Some manufacturers have
recently produced throttled back versions that might struggle on a big
house, though). You need to have a 10 bedroom 1660s place with no glass in
the windows to exceed the capability. (Well not, quite, but if the
calculation did show a bigger boiler was needed, the correct approach is to
fix the house insulation, not fit a bigger boiler).

That is very good to know. This one worried me the most.

Total quote was for £3498 including VAT (and £100 trade in discount)
with some significant numbers being (not including VAT):

Not actually that bad for a BG quote. Still much higher than a good local
engineer, but not in their normal stratispheric regions, given that the
quote includes lots of additional work to the actual boiler swap, such as
the fully pumped version, movement of the boiler, updating of controls etc.

glow-worm Xi std horizontal flue (800mm) £154

The Glowworm HXI/CXi/SXi is the boiler that is currently rescuing Glowworm's
reputation. It is certainly not scraping the barrel by going for a cheap
boiler.

I was somewhat surprised by the size of the quote and the cost of the
boiler - seemed pricey to me.

Well, BG always give the most expensive quote. Make sure you phone round
some local non-chain places.

Have done so.

Thanks again. Your post has helped sort a few things out for me.

Martin
--
Martin J. Evans
Wetherby, UK