Do you know your water heater temperature ?
To know if your hot water heater is operating at the correct temperature, let the faucet run long enough for the heated water to flow out and then fill a coffee cup and insert a standard cooking thermometer. Most water heaters average between 120 and 140 degrees. The water heater temperature setting on most heaters are very easy to adjust. You should make sure the temperature is not set too high to cause burns, especially if there are small children in you home.