Bathroom radiator has stopped switching on with hot water

[Onandoff]

Our bathroom rad heats up with the hot water so we have dry warm towels. Or we did as it stopped doing this over the weekend. It comes on and warms up nicely with the heating switched on so I’m guessing some connection has gone between it and the hot water? Any clues? It’s not a combi boiler.
Thank you

Radiators are a completely separate system to hot water so it shouldn't have come on when you are running hot water!

What system do you have?

Just spoke to husband and he said your system was probably faulty with a faulty diverter valve and that is why the radiator was heating up with the hot water.

Maybe it's self healed and now is working correctly!

Yes maybe but I know you can connect bathroom rads to come on separate to the general heating system. I think that’s what we have/had. It was the only radiator that would come on as the water heated.

@ItsSnowJokes

Radiators are a completely separate system to hot water so it shouldn't have come on when you are running hot water!

What system do you have?

Our system was set up specifically to do exactly this!

I also have one in the family bathroom that comes on with the hot water. Probably original from 1970's, and can't be individually controlled. My other one is in a later extension and comes on with the heating. Sorry, can't answer your query though!