Basin hot-water scalds
Water at 60°C scalds in five seconds — and your cylinder has to stay that hot to keep Legionella down. So the water reaching your basins is hot enough to burn a scalp, by design. Your hand isn't the client's scalp, so testing by feel isn't the control. Temper it at the tap.
This is one hazard. Your register is the set that applies to you — under 20 questions, about five minutes, free.