thank you for explaining that what a nice explanation, i've never lived with radiators so I didnt know that thank you! My 'nonsmart'(?) / digital thermostat also has programming, so I agree the heat being on before I get home is excellent. mine is just set to 5:30p m-f on the thermo.

I bet you could even do a shortcut on apple with an NFC tag that automatically sends a message to your thermo to start. Get in your car, tap the tag, your heat starts at home and then by the time you get home, boom heat. Or set just an alert that says "you're X minutes from home, start heat?"