"John Stumbles" wrote in message
...
On Fri, 30 May 2008 12:28:53 +0100, Mary Fisher wrote:

We've been very satisfied with ours, it heats water even in winter. Our
gas bills plummeted after we installed it.

Let me stick my neck out here Mary and hazard a couple of guesses:
(1) that you're the sort of people who put on a jumper rather
than the central heating when it gets chilly,

Of course - it makes a lot of sense. Don't you? Do you go out on a cold day
with no coat? Or perhaps you sit in your car in **** sleeves with the heater
full on ...

and
(2) that your boiler and hot water cylinder are pretty ancient

They were both installed in January 2006. I don't think that's pretty
ancient :-)

and
prodigiously chuck heat into the house and out the flue for ages while
heating the water in the cylinder.

Not at all.

If so then your water heating costs
would be a relatively high proportion of your total heating costs. If
you'd spent the money you spent on your solartwin on a condensing boiler
instead you might have found that your gas bills plummeted even further.

I think they couldn't be any lower but We don't want a condensing boiler for
all sorts of reasons.

So you're wrong.