ᐅ How do room thermostats work in a detached single-family house?

Good day.
I am interested in understanding how the controllers for underfloor heating, specifically the room thermostats, work.
I have simple ones with an LED light that turns on when the underfloor heating is active. The dial does not show temperature numbers but has about 15 markings.
Currently, the dial is set to marking 10 out of 15.
That means the underfloor heating only switches back on when the temperature falls below the level of that marking (but what temperature does that correspond to? There are no degree numbers on the dial).
According to my thermometer, it is about 22 degrees Celsius (72°F). So the underfloor heating heats until just above 22 degrees and then turns off. When the temperature drops below 22 degrees, it switches on again.
If I turn the dial further to the right to marking 11, would the underfloor heating then turn on when, for example, 23 degrees is undershot?
Is that a roughly correct understanding?

These simple controllers operate the actuators on the manifold valves, right?
If the controller is turned further to the right, does the valve open more (allowing more heated water through the pipe), or does the underfloor heating simply run longer with the same water flow?

Also, what happens if I replace the controllers with digital ones?
With those, you can input a specific temperature, e.g., 23 degrees Celsius (73°F).
Does the underfloor heating then simply run longer at 23 degrees than at 22 degrees, or does more heated water flow through the pipes?

I want to understand this before I talk to the heating engineer about a possible upgrade.
I have looked for information here but haven’t fully understood it.

Thank you very much.

fraubauer schrieb:

Currently, I have the dial set to mark 10 out of 15.
That means the underfloor heating only starts to switch back on when the temperature drops below the level of that mark (but what temperature is that exactly? There’s no degree number on the dial).
According to my thermometer, that would be about 22 degrees. So the underfloor heating heats up to just over 22 degrees and then switches off. When the temperature drops below 22 degrees, it switches on again.
If I turn the dial further to the right to mark 11, would the underfloor heating switch on, for example, when the temperature drops below 23 degrees?
Is that roughly correct?

Yes, something like that, but of course it depends on what kind of controller you have and which control algorithms it follows. There could be a hysteresis or there might not be.

fraubauer schrieb:

These simple controllers regulate the actuators on the manifold, right?
So if the controller is turned further to the right, does the valve open more (allowing more heated water through the pipes), or does the underfloor heating simply run longer (with the same amount of heated water)?

It depends on what kind of valves you have installed. Both options are possible.

fraubauer schrieb:

And what if I were to replace the controllers with digital ones?
You can enter a specific temperature, for example, 23 degrees.
Would the underfloor heating then simply run longer at 23 degrees (compared to 22 degrees), or would more heated water flow through the underfloor heating pipes?

Again, this depends on the internal components and the software used in the controller. The temperature can be regulated in several ways. The digital display is essentially just an interface, no more and no less.

Basically, these devices act like “emergency brakes.” If the heating “runs too fast,” they slow it down. As soon as the heating is “slow enough” again, they release and the cycle starts over. In other words, it’s a constant up-and-down cycle, which can be more or less pronounced depending on the hardware and software installed.

Mycraft schrieb:

Yes, something like that, but of course it’s unknown what kind of controllers you have and which control algorithms they follow. There might be hysteresis, or there might not be.

It depends on what kind of valves you have installed. Both options are possible.

Again, it depends on the internal components and also the software in this case. Because the temperatures can be controlled in different ways. The digital display is basically nothing more and nothing less.

Basically, these devices act as “emergency brakes.” If the heating is “running too fast,” the devices slow it down. Once the heating is “slow enough” again, they release, and the cycle starts over. It’s essentially a constant uphill and downhill ride, varying in intensity depending on the hardware and software installed.

Good day.
What do you mean by software?
The basic controllers are Salus RT10. Do controllers like these have software??
I still don’t understand this.

No, I meant the controllers with digital displays. These are usually (but not always) microprocessor-controlled, so the control algorithm is not implemented with physical components but programmed by the manufacturer in one way or another. In other words, the regulation happens through software.

The Salus models are still quite simple, without so-called software.

That basically sums it up:
In principle, the usual wall controllers (including the current ones from Salus) act as "emergency brakes." When the heating "runs too fast," they close the valve (restrict the flow). As soon as the room cools down again, the flow is reopened.

Mycraft schrieb:

No, I meant the controllers with digital displays. These are usually (but not always) microprocessor-controlled, so the control algorithm is not implemented with physical components but is programmed by the manufacturer in one way or another. In other words, the regulation is done via software.

The Salus controllers are still quite simple and do not use so-called software.

That basically sums it up:
Basically, the common wall controllers (including the current ones from Salus) act as emergency stops. If the heating is "running too fast," they close the valve (blocking the flow). Once the room cools down again, the flow is reopened.

Hello.
Ok, understood. So it's basically open and close. When the heating water is hotter, the underfloor heating runs for a shorter time; when the heating water is cooler, the underfloor heating runs longer until the desired temperature is reached. But running longer does not mean increased heating costs?

Yes, something like that. Very roughly... but you don’t need to know more about the function unless you want to go deeper.

fraubauer schrieb:

Running longer doesn’t mean higher heating costs?

Um... definitely a maybe. Heating costs are mainly determined by the comfort temperatures and the heat losses of the heated rooms/houses. The controllers on the wall are just emergency brakes and, with well-balanced systems, are not necessary at all and sometimes even the cause of higher heating costs.