Thanks for the clarification. There is a switch located just outside the bathroom. Ran some tests;
1. Turned the switch on
2. Turned the switch on and bathroom light on
Changed the fuse in the switch and retested 1 and 2. For all scenarios I left it running for 15 mins to 30 mins and there...
When the heating is turned on, all the radiators in the flat is on. But the towel rail in the bathroom does not heat up. I have a combi boiler. Photos of towel rail are attached.
Looking at the towel rail - there's a wire coming out of it at the bottom but no valves(?). I'm confused and wonder...