When hot water isn’t getting hot enough check the thermostat setting on your water heater aiming for 120 degrees Fahrenheit. For gas heaters verify the pilot light is lit and the burner ignites properly. Electric heaters may have a tripped reset button or faulty heating element. Sediment buildup in the tank insulates water from the heating source so flush the tank. A broken dip tube can also mix cold water with hot water output.