On Fri, 13 Aug 2004 15:42:55 +0100, "Ed Sirett"
wrote:

Take a look at the sealed CH system FAQ. It may well be better to heat the
heat bank indirectly from a sealed system. The heat bank water itself
beeing a simple F+E header tank.

yes, I'd read all the faq's many times.
I just had another chap round, he made what seemed like a good
negative point against sealed versus unsealed

- heating installation is 30 yrs old, mid 70's house, system
definately never been u/g'ed and there are several rads with cold
lower sections downstairs so I'm sure its got sludge in, and all the
heating pipework downstairs is buried in screed floors
- if there is any leakage, sealing/pressurising the CH circuit will
only make it more so, and as most of its buried, it'll be a complete
**** to find...

and he was at least aware of the existence of thermal store/heat
banks, but he said he had to go away and do some reading up before
recommending options..

Ian