Operation and adjustment of the underfloor heating

Hello everyone

I need help with the operation of my underfloor heating.

We recently moved into a new house. In this house, a conservatory was subsequently built, and only in this conservatory is there underfloor heating (also installed later). The other rooms are heated by conventional radiators.

Unfortunately, I am unsure about the operation of the underfloor heating.
My questions:

- Why are there two circuits (A & B in the picture)?
- Do both valves need to be open when the heating is in operation (valve A and valve B)?
- What is the function of valve C? Should it be open?
- When the heating is not in operation (plug of the pump pulled), should all valves be closed?


Thank you very much for the help!

How should "we" know?

If the heating is not in operation (plug of the pump pulled)

The pump should also be run occasionally outside of the season to prevent it from seizing.

Regarding the valves, I'll mention one possibility, but it is very vague: The circle with valve A belongs to the "normal" heating system, the other is for the underfloor heating. Valve C is used to regulate the volume flow between A and B. If it gets too warm in the conservatory compared to the rest of the house, you turn it down a bit there. Whether the valves are closed while the pump is off doesn't matter, it is irrelevant.

Thank you for the response!