How does the control of a water-bearing fireplace work with underfloor heating?

Hello,

we were at a log cabin the other day. The house has a fireplace that heats water and provides hot water, and in addition a solar system (Or solar thermal? - No idea. In any case 8m²) and a buffer tank. Nothing more. (Except for an emergency heating coil in the buffer tank). I was only roughly interested during the visit, so I didn't go into the topic further and am therefore asking here now:

The heating (meaning the fireplace) is connected to the underfloor heating. How exactly does the control work? Because apparently they have a regulator in every room with which they can turn the heating on and off per room.

But the stove keeps running all the time?? - You can't just turn off the stove. How does this regulation work? I can imagine that the buffer tank absorbs this, but after a while the water would get extremely hot and then constantly run off through the emergency overflow?! (Waste of water??) Can such a heating system be controlled based on temperature?

Who knows about this?

Why does the stove explode? No wood, no fire, should be logical. You don't have to fill the stove all the way up to the top edge with firewood continuously.

The underfloor heating system probably has a pump that directs the water into the respective circuits, which in turn are controlled by thermostats for each room.

as well as my amateur understanding.

No, but I thought it has to be on quite often in winter.....and once it's on, you can't just turn it off. Sure, you can let it burn out, but then there's no heating at all^^

There is also "a bit of wood," not like with a car where you just turn off the engine and go full throttle.

jojo is ok ;)