On Mon, 28 May 2012 10:01:31 -0700 (PDT), harry wrote:

What do you do with all that heat in this weather?

Dump it into the heatstore and use it later. That has got up to 82C
the last few days. A couple of ordinary baths or one teenage daughter
soon gets it back down to 70C or lower. Teenage daughter with hair
wash and bath brought the backup oil boiler on last night... IIRC
that comes on at 60C and off at 65C

--
Cheers
Dave.