Can I use a radiator cover with my tado valves attached
Only way of knowing is to try one.
The main issue would be communication with the hub, if you have that then they will work.
only thing then is the enclosed space and whether the heat. In the cabinet shuts the valve off early?
You can, but would then need to use a Smart thermostat as a room sensor. This is supported, but may need to be configured by our support during the installation.
Thank you to everyone who answered my query. The wife will have to live with the radiators as they are
I have installed Tado smart radiator thermostats on several radiators with radiator covers placed in several rooms. Do I need a smart thermostat in every room or do you know any other solution where I can use an external (outside the radiator cover) temperatur sensor, maybe another brand (via ifttt) ?
A Tado smart thermostat in every room might be a too expensive solution.
If each room has radiator covers then yes each room would need a Tado Smart Thermostat.
As others have indicated the radiator cover would lead to the temperature sensors in the Tado Smart TRV becoming inaccurate. Currently the only external sensors that the Tado Smart TRVs can link to are either the Tado Smart Thermostat or another Tado Smart TRV.
Being that the Tado Smart TRV is cheaper than the Smart Thermostat some people have used a spare one placed on a shelf in the room and used it as a cheaper solution.
There is a 'campaign' to get Tado to make and sell a cheap external temperature sensor. I suggest you vote for it here.
Launch an external temperature sensor for the Smart Radiator Thermostats