Controlling your water tank temperature can help to prolong the life of your tank, but it can sometimes be more difficult than it looks. If you are considering doing this yourself, the most important piece of information you will need is the location of the thermostat. This little device will often be screwed to the tank on a gas hot water system, but may be hidden behind metal cover plates in electrical systems.
Adjusting the Temperature
Before you touch the thermostat, make sure that the power is turned off to the heater. Remove the metal cover if necessary. Mark the place where the thermostat was set. Also mark where the thermostat ends up, in order to assist future repairs. Turn the thermostat around carefully, and then turn the heater on. Check the temperature of your water, and make any further adjustments to get the correct setting.
Never make your water temperature lower than around 131 degrees Fahrenheit because temperatures below this amount can encourage the buildup of bacteria, and may lead to additional scaling or corrosion of your tank. If you are trying to turn the temperature up, make sure that the heat does not get so high that you risk scalding yourself under the hot water.