Thanks to the kids who winter sport on the hill behind our house (and leave their broken sleds behind), I have another drip tray, to stop more glycol leaking into the chipboard floor. It is just the perfect length, width and height!
The insulation will have to wait until another day, as I need to see the system working first, without a leak. The valves are all open, to allow the system to refill (having been drained at the weekend), and then the two Yellow ball valves will be closed. After that, they will only ever be opened for maintenance or isolation purposes.
The Heat Exchanger is connected with flexible pipes because I wasn't quite sure where it would finally be positioned, and there is a chance I might want to get one double the size if this one proves the principle, but is insufficient. Note that the direction of flow has to be in opposition, hence the crossover of the pipes.