Just like others already replied, hardware monitoring on OS level is up to you. For disks, they even provide documentation on how best to set up smartd on Linux, and I'm sure they have some similar docu for Windows. In fact, their technical documentation is excellent in general.
But they often go even above and beyond for you. I rent several servers from them for many years, and I've had it happen once or twice that I got an e-mail from their datacenter team telling me that they noticed an error LED blinking on one of my servers, and actively offered to plan a repair intervention. All I had to do was to come up with a downtime window and communicate it to them. Very slick.
I'd say about half of overall value of Hetzner is in their quality support.
But they often go even above and beyond for you. I rent several servers from them for many years, and I've had it happen once or twice that I got an e-mail from their datacenter team telling me that they noticed an error LED blinking on one of my servers, and actively offered to plan a repair intervention. All I had to do was to come up with a downtime window and communicate it to them. Very slick.
I'd say about half of overall value of Hetzner is in their quality support.