Understanding Underfloor Heating Manifold Functionality: Valve Control, Loop Effects & Beam Usage

Hello,

In the house, we have one manifold on each level, as in the picture below. In the upper part, we can remove the red caps and then we can twist or unscrew the valve. I have a few operational questions:

1. When one of the upper valves is turned off, the pipe with the red conduit cools down (i.e. we cut off hot water for a given loop). Changing the settings of this valve even for one loop affects the operation of other loops (although I do not change others).

2. What is this lower beam in the manifold for and how does it work?

The manifold beam is simply a hydraulic fitting, just like a T-piece or a cross-piece, only built to facilitate the assembly, connection and adjustment of the floor loop.
Most often, one is used to regulate flows (throttling) so that all loops have a flow appropriate to their length, regardless of internal resistance.
On the second one, thermostats are usually placed, closing the flow on a given loop if the return reaches the appropriate temperature set for a given loop, thus allowing for faster heating of the remaining loops, and finally turning off the flow on a given manifold and turning off the boiler.
I guess you have a condensing boiler, operating at low temperatures, because you do not see the mixer and the floor pump at the manifold.

Thanks for the initial description. The house is heated by a heat pump so yes - there are low temperatures here and it works.

However, I want to know how to control the temperature in individual rooms. If the upper beam controls the flows, and these were calculated by the engineers designing the floorstanders, I assume that they are well done.

On the lower beam you can see thermostatic valves that I can turn. I don't know what effect it has on the system though. Does such a valve for each loop work the same as the valve on traditional radiators, i.e. when I turn it on, it "gets warmer"? If the thermostat is twisted (max. to the right), does it throttle the flows? I will be grateful for the info.

If you reduce the temperature on any of the thermostats, the given loop will be closed at slightly lower temperatures of the water flowing through it, and thus the maximum temperature will decrease. for a given room.
More accurate regulation of the room temperature can be obtained by installing valves with a capillary that receives the room temperature, or similarly operating valves, controlled by a room thermostat.

Thanks! To be sure - so if I open the thermostatic valve on a given loop to the maximum, I will get the maximum temperature on it. Is it correct?

Does the replacement of these valves from manual ones to more automatic ones involve draining water from the entire floor?

1) Yes, if you open the valve more, you will increase the temperature of the room heated by a given loop.
2) You don't need to drain the system as you are only replacing the control head, not the valve itself. You probably only have adjusting nuts in place of the thermostatic heads.

Thank you for the description. I just unscrewed all the valves on the lower beam, I will observe for two days and in warmer rooms I will start closing.

Currently the bottom bar is like this .

Can you provide a link to your solution?

See in the link.
http://www.ecologhouse.org/wp-content/uploads/2008/09/underfloor-heating-actuators.JPG

As in the link it is called "underfloor-heating-actuators".

Added after 3 [minutes]:

http://underfloorparts.co.uk/product-category/actuator-heads

"I'll reheat the chop" so as not to start a new thread.

For example, in the cooling system in a car it is clear, the thermostat opens at 90C and closes when the temperature drops.
I did not notice that the manufacturer of thermostats for manifolds gave a certain range of their operation.
I have this contraption on my table and I did a little experiment.
I heated the water to 50C to 60C upwards, until finally I poured boiling water and nothing. They don't even budge.
I tried 2 more with no success.
I didn't want to try any more.
Has anyone ever tested it?
Or maybe the thermostatic head (purchased separately) is responsible for opening and closing the loop, because these plastics can only close the circuit in the loop. Alternatively, when twisting and leaving a gap, reduce the flow
Please correct me if I'm wrong.

These small nuts on the manifold are nothing more than knobs for manual closing-opening and adjustment. When assembling the heads, these nuts are removed and the thermostatic heads are screwed in their place.