[briers]

I've noticed nearly every trv in my house making a very annoying whistling noise now. Some louder than others. I'm pretty sure some are out of calibration too. Can anyone recommend reliable ones? I need about 20 so preferably not top whack ones. I noticed the heads unscrew, do you replace just the heads or the entire valve?

Also I would like to get a better digital programmable thermostat. I run our heating 24/7 so having it adjust the temp down from 20 to 15 overnight and some afternoons is very handy. Problem is our current one is crap, letting the temp drop too far then blasting it up and over the set temp. I would rather just have it top up. Anyone have any recommendations?

Thanks