Thermostat normally closed (NC) or normally open (NO)

Dear members,

unfortunately, I have not been able to get any useful information yet. I currently have Cosmo thermostats installed and would like to replace them. According to my heating engineer, I have normally closed valves installed. Can someone tell me whether I can install normally closed valves again or if I can also install normally open valves? Thank you very much.

Would you like to replace actuators or room thermostats? Or both? And why?

Hello RotorMotor,

thank you for your reply.
I only want to replace the thermostats. The reason is the appearance. In my eyes, they are simply no longer up to date. You build a house for over half a million euros and then have thermostats on the wall that stick out 3 cm and look as if they were from 1998.
Thank you very much.

I just want to replace the thermostats. The reason is the appearance.

Then just take the opportunity and do without both actuators and room thermostats.

Why give up? What do you mean by that?

Why give up? What do you mean by that?

I mean exactly what I write. Unscrew the actuators. Get rid of the thermostat. With a properly adjusted underfloor heating system, these things are unnecessary, as they don't really have any effect anyway. Feel free to read up (people use the informal "you" here ;)) on the topic of "hydraulic balancing" and "thermal balancing" of an underfloor heating system.