On 29 Aug 2004 00:45:23 -0700, (Boovee) wrote:

Hi, I`ve trawelled through the NG`s regarding this but there are a lot
of old posts on the subject. Can it be brought right bang up to date.
The questions I`d like to know please a
Are Condensing boilers now reliable?

Definitely as long as you buy one manufactured in or using parts and
designs from Germany or Holland.


If this is the case, are the Ravenheat models sold in B&Q any
good.....older posts suggest not but why would B&Q stock them in they
were inferior. Has this model improved?

These are at the low end of the market to be kind about it.

Is the Worcester still the
King of the boiler crop?

It's one of the best among the boilers having large sales volume in
the UK, along with Vaillant. There are better products such as
Viessmann and MAN, but these are in the £1500 area.


Why is there a reluctance for a fitter to suggest (or even pretend not
to know about!!) a condensing bolier?

Because either they don't understand them or have been hanging around
plumber's merchants too much and listening to old wive's tales. The
early generation of UK manufactured condensing boilers were not
designed properly and used inappropriate materials. As a result they
were unreliable. The heating installation industry is conservative.

Within the next year or so, most new boilers sold will be condensing
types as a result of changes to the Building Regulations so they will
soon learn about them.


Around what sort of reasonable
price would I expect to pay for a good, not overly expensive decent
boiler? Any recommendations?

The Worcester Bosch products that you mention are considered to be
good products and value for money.


I am in the process of replacing my old gas boiler. The house will
need an extra 4 radiators taking the total to 10. What sort of BTU
rating condensating boiler would I need? I do not intend to run my two
showers of this new boiler (not yet any way).

Forget about using BTUs and work entirely in kW and metric units. The
arithmetic is easier and you won't make mistakes by accidentally
mixing units.

It is better to do a heat loss calculation for each room of the house
and work out the radiator sizings from that. You can then add those
together, apply a margin of say 20% and go from there. It is
meaningless to work in terms of number of radiators because they vary
in size enormously - from say 300W to 6kW.

You can get calculator programs from radiator manufacturer web sites
to do the sums.,

Having said that, modern condensing boilers modulate the heat output
to match the load, so the point is to go for an adequately large
boiler to cover the worst case. It will reduce output when the
weather is warmer.

If you use a fast revovery hot water cylinder, you will want plenty of
heat output from the boiler for that, which is why 25-30kW boilers
have become typical.





Thanks in advance for the replies. I know there are lots of questions
but I have very limited time to get a replacement.......
DB

..andy

To email, substitute .nospam with .gl