Error 5077/33 due to presureless storage tank?

[cj0]

I'd wish to simulate seasonal storage with an 87.500 liter storage tank.

Purchasing / filling the storage tank with VDI 2035 compliant heating water is not cost effective. Thus storage tank water needs to be plain tap or even groundwater and operated pressure-less (at atmospheric pressure). As a result the storage tank has all 10 "Ports" configured as "Empty". Coil 1,3,4,5, and 6 are configured with coil heat exchangers.

The much smaller volume collector and wall heating circuits will be filled with osmosis water (thus VDI 2035 compliant, I suspect)

Now the Polysun 2022.7 simulation (of a modified Ritter SFD) fails with Error 5077/33:

The loop "Water" does not contain any flow rate producer.

I suspect that this "Water" loop, is the "Water" in the storage tank. Which is intentionally configured without flow producer.

How to workaround this 5077/33 error and create a seasonal storage without pressure and flow?