Smart radiator and thermostat and settings

[AITAH10]

So I did something a bit silly. I kept hearing how smart radiator valves and thermostats can save money so I got it for my parents.

When I set it to 20 in the front room it went to 20.4 and the kitchen was climbing and to 20 and the conservatory was at 18.

I set it to 17 almost 2 hours ago and it's still 19.7 in the kitchen and 18.8 in the front room. 15 3 in the conservatory.

So what settings do people use? Do you set all the rooms to the same? Bedrooms etc at lower or fully off? Do you turn the radiators fully off when they get to temperature?

Have you seen a big reduction in costs?

We’ve got them and have seen a very small reduction in cost but a warmer house. We have rooms set to 15 over night and 17/18 during the day when they’re not being used to keep the chill off. Then 21 when we are using them. Eg, bedrooms are on an hour or so before bed and before we wake up.
Don’t forget that the temp displayed is the temperature at that spot by the radiator, not the overall room temp. We found we needed to set them slightly higher to account for this.
the radiator valves are constantly opening and closing to keep the temperature as constant as it can. It does fluctuate within half a degree or so.