On 29 Mar 2007 13:19:38 -0700 someone who may be "jives11"
wrote this:-

Many thanks. I had not thought of that. So how do solar water heating
systems avoid this ? I'd assumed they preheat stored water before it
enters the boiler.

Assuming you are thinking of the domestic hot water heating part of
a combination boiler, the solar panel will feed a relatively small
hot water cylinder from which water to the boiler is drawn (either
directly or via a heat exchanger). The combination boiler must be
able to accept heated water.





--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54