Think my radiator temperature thing is broken.. any ideas?

You know the temperature thing you turn round from like 0 to 5 depending on how hot you want it to be? Well I think, in trying to turn it off I may have turned it too far. As the it just keeps turning but in a jerky movement and the number doesn’t change if that makes sense? Like there’s a little plastic arrow that points up at the setting it’s on, so that you know what setting it’s on. But now it’s like the whole thing is turning rather than just the plastic cover with the numbers on.

So I think (well I’m hoping cos the opposite would be worse) that it’s now turned completely off and there is no way to turn it on. But because the whole thing is turning and the numbers don’t change up or down regardless of which way you turn it, it’s possible it could be on any one of the 0-5 settings but only stuck as showing on 0.

Hopefully this is the right place to post this and someone has some idea…?

Cheers!