If the temperature of your hot water is too high for your liking it is relatively simple to turn it down.
It is quick and easy to adjust the temperature on a combi boiler. Locate the digital control panel or temperature dial on the front your boiler and make your adjustments for the hot water (which will not affect the central heating temperature). The result will be instant.
It is a little more involved for conventional (heat-only) or system boilers as you will need to locate the thermostat and adjuster on your storage cylinder. Once the adjustment is made, you will have to wait a few hours to notice the change as your cylinder will be insulated and so take time to cool down.
However, it is not advisable to set it lower than 60°C as that is the minimum temperature required to kill most bacteria in your stored hot water.
The same principles apply when turning the water temperature up but if it is set any higher than 65°C there is an increased risk of scalding.