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,.

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?

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.

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.

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.

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.

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.

- 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).

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.

Christian.