6 May 2012: The plumbing for the Heat Exchanger is started now, mostly using recycled pipe from previous work. The previous work was difficult to take out because the evacuated tube plumbers ran the pipe along the floor, with a drain cock actually on the floor, so draining it was a problem. There is no space for any sort of a drip tray underneath. There will be one when the replacement work is finished.
Here are some of the components needed - including the insulated box. I shall reuse the yellow lever ball valves, to make it possible to enable or disable the heat exchanger at the simple turn of the valves, and also to link the circuit to the existing top up vessel.