Becuase 70 is too low to fill my bath up right, i need to have boiler on for an hour put 4minutes of hot in, have it on for another hour out 1min of cold in 3 min of hot then it is hot and full ish!, so it is much easier not to use thermostat at all, but then not good if i forget to turn off so 85 degree thermostat should be fine and i will get a timer also. An Electrician/plumber has hard a time believing this in the past but what can i say this is my real experience, maybe my hot water tank/boiler is too small for the size of my bath, or it is filled half with sand or something.
But i dont use hot water for anything else so there is no safety issue and 85 degree thermostat is safer than none at all.
So please if you can help me find one then great, otherwise dont worry about it!