I'm back at this now I've a bit of space. First remove most of the clutter. The heater tank may or may not stay. There's an element inside I might be able to use, it'd mean simpler plumbing but less soapy water capacity. We shall see. Leaves me with this: The pump has an RPM on it so I don't think it needs electronic control, that could make the wiring easier: The first thing I have to do is make a valved drain. I'll need to decide on fittings for that.