On Sun, 18 Sep 2005 22:24:24 +0100, "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
Would you think a new back boiler would be *much* more efficient than
a 25 year old one (allowing for wear / tear etc) and how far off that
would it be compared to a new 'super duper' one do you think please?

The problem with a back boiler is that it pulls in hot air from the room
and shoots it up the chimney - to be replaced with cold from outside.
Which was known to be inefficient long before condensing boilers arrived.
Hence balanced flue boilers which have been around for many a year.

Hmm, good point .. didn't some boilers require an input duct so they
do actually collect their input air from outside (like a balanced flue
jobby) though? I admit the front fire would still consume room air and
send heat into space ... but wouldn't the exhaust gasses (back boiler
and front fire) give some of their heat to the chimney breast /
internal stack and hence to the house on their way out (where a
balanced flue wouldn't)?

Personally, I'd investigate replacing it with a modern condensing type.
The fuel savings may well repay the cost quickly. And, of course, there
are the safety benefits of a room sealed device.

Worth investigation indeed (but reluctantly no doubt). ;-)

All the best Dave ..

T i m