"sro" wrote in message
...

"Christian McArdle" wrote in message
t...
He also said that modern boilers used insulation to stop wasting heat
by
transfer into the surrounding space and that they do achieve lower
flue
temperatures which means they are extracting more heat from the gas.

Indeed, although it is the much larger, more efficient heat exchanger
which
does this, rather than insulation.

A well designed condensing boiler installation might have a flue
temperature
of 50C, compared to an old boiler with 300C. The flue temperature being
considerably lower than 100C is the cause of all the pluming. Although
people worry about it, thinking it is a health hazard, the emissions in
that
plume are much better than those in the invisible 300C one. But you
can't
see the 300C version, so no-one cares.


Thanks again - and now the real question,
are condensing boilers unreliable ?

No. They are same as a system boiler except they have a plastic drain pipe
attached.

Here is an example of what I want from a boiler :

- Run for 18 years with minimal ( 3 or 4 thermocouples )
maintenance ( my old fashioned boiler )

That is possible, but you have to buy a top of the range boiler. As in all
aspects of product prices, more expensive "generally" means better quality.
Not always though.

- I find it amazing that modern combis seem to need new bits after a
couple
of years

Depends on what make and model again. Cheap units break down more. Poorly
installed units break down more too. A combi is just a system boiler with a
water section. No reason for it to be unreliable at all. Some combi's have
all the functions integrated to ensure no operating problems. The
Microgenus is one boiler with all integrated.

Am I being unrealistic

yes.

- are all modern devices complicated and unreliable ?

No. Depends on what you buy.



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