Water is too hot in electric water heater
Easy fix: add an anti scalding valve right after your boiler. Remember that water under 60°C will incubate legionella that is quite dangerous so don't lower boiler's set-point temperature below that.

Also remember that (tanked) boiler work by stratification it means that quite hot water stays at top of tank while cool one lays at the bottom, so it's normal that 'first' water is hotter than set if the sensor isn't in the boiler's top.

Note: water above the sensing element is hotter than set point, water below sensing element is colder than set point.