Smart thermostats by connectivity

SONOFF

NSPanel WiFi Smart Light Switch, 2 Gang Switch Smart Home Co...

A cheap smart wall panel that’s great if you like tinkering

meross

Smart Thermostat for Electric Underfloor Heating, WiFi Therm...

A no-fuss underfloor controller that plays nice with Matter

meross

WiFi Smart Thermostat Works with HomeKit Alexa Google Home,...

A simple way to make dumb heaters a bit smarter

Vine Thermostat for Home with Touchscreen Color Display, WiF...

Cheap smart control with a few rough edges

Hive Thermostat For Heating Control (Combi Boilers), With Hi...

Simple smart heating with a few quirks

Ecobee EB-STATE3LTP-02 Thermostat, Black

A smart thermostat that’s solid but not mind-blowing

Ecobee3 Lite Smart Thermostat with Whole Home Sensors Bundle

Solid smart control if you’re ready to tinker a bit

Google

Nest Learning Smart Thermostat 3rd Generation Home/Office Wi...

A smart thermostat that mostly just works