Hello Luxikon
I have (and love) the CPP2. In my case, I keep it under my sink when I am not using it, and bring it out when processing film, so I am filling the bath each time. If I am processing B&W - which is what I do most of the time, then I fill the bath with water from my tempered water tap, since this is quick, and it doesn't take long for the bath to stabilize at the 20C temp that I use for processing.
There is an overflow thing, so you can fill the bath fairly full, and then when you put the bottles of processing chemicals in, it will drain down to the proper level.
Once the bath is mostly full, I turn on the pump/heat switch.
If you process at 16C, then you need to make sure that your cold water inlet is at a temp below 16C for the cold water solenoid to work to cool the process down. In the summer time this might be an issue, depending on where you are. If so, one thing that I will do is to take a 1L bottle and fill it with ice, and put that in the bath, well away from my developer bottle, this helps to keep the bath cold. You will have to replace ice bottles if you are doing several runs one after another.