On Mon, 16 Jan 2006 17:27:00 +0000 (UTC), "John"
wrote:



Come on Andy, The flue of an Aga has a draught break which entrains lots of
cool air so any temperature after such flu break is NOT an indicator of
efficiency

I used to laugh when I came across test point holes drilled after flue
breaks, usually with service record cards dutifully filled in with
combustion analyser results taken straight out of the manual but quite
obviously not the readings from the point :-(


I see your point, but was not trying to suggest a scientific
measurement. In fact, the cast iron vertical flue after the flue
break is relatively hot (I may measure it later if I have time and can
find the IR meter or thermocouple probe); however at the point where
the flue enters the loft (some metres away), it is considerably
cooler. This represents heat released within the fabric of the house.

If the cooker were a balanced or power flue type, I agree that that
would be a different matter.

--

..andy