SRTs work but Smart Thermostat won't turn -itself- on

Rawling

I've got a setup like 4A here - a Wired Smart Thermostat in the hall with a couple of plain radiators, and several rooms each with a radiator with a SRT:

How does tado° control radiator heating systems with a central thermostat?

https://community.tado.com/en-gb/home/leaving?allowTrusted=1&target=https%3A%2F%2Fsupport.tado.com%2Fen%2Farticles%2F3481994-how-does-tado-control-radiator-heating-systems-with-a-central-thermostat

If I turn up the temperature for one of the rooms with a SRT in, the WST relay goes and that radiator (and the hall radiators) heat up.

If I turn up the temperature for the hall, it says it is heating, but the relay doesn't go and the boiler doesn't come on.

I can't see any setting in the app that I might've changed to cause this. I got a "window open" notification for the hall once, but cleared it and the app seemed to go back to normal.

johnnyp78

Does the hall room on the app have a zone controller? You can see under settings > rooms

Rawling

Yes - since the room contains the smart thermostat, it's locked to its own zone and can't be set to independent.

johnnyp78

You might need to check with Tado support, it sounds like it isn’t correctly set up.

Rawling

Is Chat the only support option? It's been 2 days now and no reply, I just watch the little heads change over time.

Rawling

... and then the thermostat starts working, briefly, and now it refuses to turn off the boiler at all.