You do seem to have some fixed ideas and to ignore our advice.
Now you want to risk killing her from legionella!
Well, having left the thermostat set to 45C thinking it might bring the tap temperature down nearer 60C, I measured the water today at 47C. It's possible to wash your hands under the running hot water alone now, so Mum is happy!
I don't know what temperature the water is being stored at, as there's obviously a heat loss in the pipework, but I'm guessing it can't be far below the recommended 60C if it comes out of a kitchen tap at 47C?
I think I'll tweak the cylinder thermostat up to 50C and work on the basis that the water is probably stored at a safe temperature, but cool enough that Mum's guest will stop scalding themselves when they wash their hands!
Thanks everyone for your help!
I thought the water temperature had to be above 55C and preferably 60C to kill legionella bacteria.You need the stored water to be below the stat to be 55C to kill legionella in the hot water tank, the stat is a third of the way up to ensure all the water above it is at least that temp.
If the cylinder is well insulated the drop in temperature will be very small.But what about all the times when the heating system is switched off? Surely then the cylinder temp will go back to ambient?
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