On Wed, 05 Jul 2006 09:16:30 +0100 The Natural Philosopher wrote :
Its hard to say what ab actual modern domestic boiler REALLY achieves in
PRACTICE (as opposed to measurements after 15 minutes of firing at full
power) but I suspect its very little different to 65%.

The SEDBUK efficiency (around 90% for most condensing boilers) is
calculated on 50% at full load and 50% at 30% load.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk