Smart Radiator Thermostats
Are a step beyond Smart Thermostats. They further improve your energy efficiency by adjusting the temperature of individual rooms. Like Smart thermostats, they learnt you home, but down to individual room level. For example, during the daytime, they can turn down bedrooms while making sure your living space is nice and warm.
Community members have good experience with both:
These typically require professional installation, although a competent electrical DIY’er could self install.