Originally Posted by
MichaelD
My HR92s and HR80s are noticeable, but quiet, we don't ever notice them, and I've never known visitors being distracted by them, although when we got a kitten she was a bit spooked for the first day or so, now she doesn't seem to notice them, just like the rest of the family.
The one exception is when they do their weekly exercise of going fully closed to fully open and back during the summer. Probably because we are less used to the noise, and because it goes on for a while.
I had heard that motorised valves on aluminium radiators are loud, because of the nature of those rads, so it might be that different HR92s give different noise levels because of the different rads they are connected to? Do any need bleeding?