On Sun, 22 Jun 2008 15:01:19 +0100, David Hansen
wrote:

On Sun, 22 Jun 2008 14:58:23 +0100 someone who may be MM
wrote this:-

If it is really a problem I'll just run some cold water into the tank.
Or cover the collector with a shiny reflector to shield it.

Are you around all the time during daylight to do this?

Yes. I'm retired. If I go off somewhere on a very hot day, I'll just
shield the collector so that the temperature is reduced. I won't need
the hot water anyway if I'm away. Actually, I have designed the whole
system to be unclipped easily for putting away during winter.

MM