On Fri, 17 Jun 2005 14:25:01 +0000, Martin Evans wrote:

I've had a British Gas man around today to quote for a new condensing
boiler. My existing set up is:

o boiler - very old - over 25 years, wall mounted. Flue straight out
back to outside above head height (about 5-6ft to next doors house).
o gavity fed hot water with thermostat on tank, controlling valve
(motor currently broken so manually fixed open although I have a new
motor for it) and boiler
o water tank in loft feeding central heating
o one room thermostat in hall
o most (not all) radiators with TRVs - radiator in hall where room
thermostat is located does have a TRV.
o newish (3 years) programmable controller with separate CH and HW
settings and 1 hour, overrides.
o relatively new (3 years) myson cp53 pump.

During the conversation he told me:

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

Almost certainly true.


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.

If the wall stat is in a good place then the TRV should go.
A good place for a wall stat:
a) Not subject direct heat (from sunlight, radiator, or other source of
heat).
b) In a room that is representative of the heating as a whole.
(i.e not in cooler rooms/ bedrooms/ bathrooms).
c) Not in a room with an additional source of heat (not in kitchen or
living room with fire)

This invariably makes the hallway and maybe the living room the best
places.


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.

They are fitting something modern , so likely true.
There is no easy way to go all TRV and comply with Part L.


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.

Find out the model, download the instructions and decide for yourself -
it's likely true.



5. Our gas meter was not earthed and so they would have to earth it
all. I'm not this is true since I remember a large earthing strap
behind the gas meter where the pipes come into the house - I cannot
investigate this now.

The correct place is on the first 600mm of outlet (your) pipework.

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

Dropping the condensate into the soil pipe is acceptable.



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.

OK this is the first one I'm unhappy about. The HW cylinder must (same
'must' as q1) be a fastish recovery unit (less than 25mins from cold
IIRC). Such a cylinder will likely be able to take the bulk of the
boiler's output.
In my own home a cylinder reheat cycle take c. 10mins this consists of
60seconds of 25kW follwed by c. 10 min of ever reducing power output till
the cylinder stat call time.
The cylinder is adjacent to the boiler and is about 1m there and 1m back
as the Irish say.



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.

True. True. True. But any good heating engineer is going to recommend the
same. Pump is likely in the boiler.


9. It was around 3 days work.

True. for 2 experienced guys.



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

So they messed up.


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

Maybe so.
However, I thought that by the book the wiring for heating controls
should be in cable with flex outlets adjacent to each sensor/appliance.
Usually they are just done in flex throughout . Cable _is_ incorrect.


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).

OK On the [mandatory spit] C&G energy course some of us locked horns
with the tutor on this one. I maintained that the _first_ question to ask
was "How well did the heating work [before it broke!]" and this along with
experience and further questions like "Was there anywhere always too hot
or always cold". _Then_ you could run through the calculations to see if
you need to size up or down a bit (or even a lot).

The tutor maintained that you run through the standard assessment calcs
then size the boiler and ignore the existing installation (what utter
********).

It is true that modern boilers are considerably more forgiving of being
over-sized than older models.

The BG guy here is plain wrong and would fail a C&G assessment.



Needless to say I was less than impressed but then came the:

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

British/Scottish Gas 330 HE Condensing Boilrer (inc labour and
installation) £1559
specialist building work (3) £174
can't imagine what this was other than repositioning flue
connect boiler electrics and test £64
glow-worm Xi std horizontal flue (800mm) £154
glow-worm Xi flue extension (500mm) £28
glow-worm Xi 90 flue elbow £31
radiator valves (15mm angled W/H & L/S) £26
Now he has left I don't understand this as we never spoke about
adding radiators or valves.
controls pack (2*22mm 2Port) Prog. (UP1) £307
convert to fully pumped 22mm (5mtr head) £312
powerlush - £195
install ME bonding £112
exectrical and mechanical supp bonding £79

there was other stuff like waster disposal, pipe insulation, fit pipe
insulation etc.

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

Any useful comments?


An independent fitter if you can get hold of one should be around £2250
give or take. They are Fleecing it heavy on the controls. I'm nigh on sure
you can buy the whole lot for just over £100 (on a bad day).

I can't be bothered to look up the boiler on the net but I'd be surprised
if it's much over £700 + VAT.

The 'advanced' controls are subject to reduced VAT (5% IIRC) which is just
tokenism on the part of the treasury, IMHO.


--
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