I have two in my sitting room, both of which I know are correct. One says 85C, the other is supplied for oldsters, the top rating is 27C (80F), It is, of course, up to the maximum. Beside the reading to says:-
TOO WARM above 75F/24C - Unless you are feeling cold, turn your heating down and save some money.
That's a handy tip for tonight.
Mrs Bouquet