Thank you very much Wrigglefingers,
I really like and interested in your idea of a skin tank (especially as a young lad I looked after my grandmothers house when she was ill in hospital - this had a stove with a back boiler and I forgot to turn on the central heating pump and ended up splitting the hot water cylinder OOOPPPSSS) I was wondering are you planning on using TRV's on the radiators? Also are you planning on running the water through the skin tank constantly or are you installing a thermostatic valve that will only let the water flow through the skin tank at a certain temperature?
Cheers David