Floor heating circuit "deactivate" -> What is the name of this coupling/screw/cover?

Two circuits are controlled with one thermostat, so I can hardly turn it down to zero... Or what do you mean?

That is basically possible, but definitely not the case here.

Our towel radiator has a manual control, I can take a photo :D but what they are called o_O

Manual controllers or not?

If there was an electric actuator on it --> make it powerless?

Yes, of course it was on there before. I always thought that when powerless they would be "open", meaning the water would flow through fully?! Is that actually not the case? If yes, my question is of course doubly stupid :eek:

That is basically possible, but definitely not the case here.

Hmm, why do you think so? Definitely two actuators are controlled by the same thermostat :rolleyes:

Hmm, why do you say that? Definitely 2 actuators are controlled by one and the same thermostat :rolleyes:

Where is the second actuator? One seems to have been replaced by a clamp..

Look in the manual of the actuator. Most of them are closed when de-energized. So screw the thing on and do not connect it.

There is a square on the nipple that you can turn, but remember the number of turns because that is actually the setting of the hydraulic balancing.

There are all kinds, whereby in my opinion nowadays fail-safe open are encountered more often than fail-safe closed. This also makes sense in that they should always be open with a properly adjusted heating system.