Our domestic hot water is coming out really hot, too hot to touch. Overall the timings of the heating and hotwater are controlled by a Tado unit which is working fine. There's a Rhino oil boiler that feeds into ACV Smart cylinder and there's an immersion fitted into the cylinder. The immersion heater is definitely off at the wall connection and also at a separate isolator switch in the kitchen, so I don't think this is the problem. Inside the boiler cabinet, there's a temperature switch with settings from 90 to 60 and it's set to 60, I've adjusted the knob (it'll only go anti-clockwise towards the 90 position) with no success. I also tried checking the position of the knob and it's fitted properly on the spindle so it's not twisted around out of position. My guess is that there's possibly a fault on the thermostat. What do you think? Where do I go from here? Thanks!