Just to say, that if you've already got a device with the same name as a room, then Alexa won't work.
For example, I have a light in the office called 'Office' and the room itself is called 'Office'
So when I ask for the temperature, Alexa is getting confused and says 'that device....' etc...
Bit obvious really, but she's discovered over 100 devices in the house, and sometimes I lose track of whats what.....