27 Sept 2011: I decided to draw a revised schematic diagram for the plumbing as I am working on another paper (for China) and need a better illustration. When I explain the system to people using the blog, I have found that I do not have a diagram that states it clearly enough. So here is a new diagram.
|The thermostat decides if conditions are right to open or close|
the solenoid valve and switch on the little pump