Your hot water heater has a thermostat that determines the temperature of the hot water that comes out of your faucet. If you think your hot water is not hot enough, you can simply turn up the thermostat. This task requires only minimal handyman skills; it takes only a few minutes, and the only tools you need are a screwdriver, some protective gloves and a flashlight if the water heater is in a dark area.
Turn off the electricity to the hot water heater at your circuit breaker.
Locate and remove the exterior access cover plates; the rectangular panels are held in place by a screw on the top and bottom. This reveals the thermostats. There usually are two thermostats on electric water heaters. There might be a lot of insulation, so put on gloves and move the insulation out of the way, if necessary, to have clear access to the thermostats.
Raise the thermostats to the desired temperature. Be sure to raise the temperature in both thermostats. Raise the temperature by turning each gauge to the right; turning to the left lowers the temperature.
Put on your gloves, and replace the insulation. Replace the access cover plates on the hot water heater with your screwdriver.
Restore the electricity to the hot water heater. Allow about 45 minutes for the water temperature to change, then enjoy a nice hot bath or shower.
Don't turn up the temperature too high, because extremely hot water can scald and cause burns.