Whether you have a gas or electric water heater, the default temperature set from the factory will be between 120ºF to 140ºF. It is estimated that the average water heater temperature is set to 130ºF in the United States. 130ºF IS THE BEST TEMPERATURE TO SET YOUR WATER HEATER as it will reduce the risk of scalding while showering but also be hot enough to meet your dishwasher and washing machines recommended temperature for an optimum wash cycle.
It is acceptable to turn your water heater as high as 140ºF if required but higher energy consumption will occur. Be aware that turning up the temperature on your water heater WILL increase your electric or gas bill every month. Adjusting the water heaters temperature higher is sometimes required if it is located far from the point of usage or if it is not properly insulated. If your shower is located on the other side of your home from the water heater, you may want to adjust the temp higher. If there are multiple showers in your home and they are all being used at the same time you can adjust the temperature to prevent running out of hot water.
Increasing your water heater temperature by just 10ºF from 130ºF to 140ºF may increase heat loss resulting in a larger electric bill from $30 to $75 dollars annually. Setting the temperature to 140ºF can also increase demand losses resulting in an annual expense of up to $500 dollars. One benefit from setting your water heater to 140ºF is that this temperature is hot enough to kill almost anything that could be growing inside the water heater itself. If you do decide to raise the temp on your heater for whatever reason, use caution when using faucets, bath tubs, or showers as severe scalding can occur. To minimize the scalding risk, you can install mixing valves or other temperature regulating devices on any taps you use for washing or bathing.
Most households can have the temperature set between 120ºF and 130ºF on their water heaters. If you are concerned about energy savings and reducing your monthly energy bill then set your heater temp to 120ºF and see if that is sufficient for your needs. If 120f if not hot enough, try turning the temperature up in 5º increments until you reach the perfect temperature for your needs. For further energy savings consider extra insulation for the water heater itself and the copper water pipes too.
Before you adjust the temperature on your water heater:
Read your water heater owner’s manual for instructions on how to operate the thermostat (whether Gas or Electric).
FOR GAS WATER HEATERS: You will find a thermostat dial near the bottom of the tank on the gas valve.
FOR ELECTRIC WATER HEATERS: You will find thermostats positioned behind screw-on plates or panels. For safety purposes, shut off the electricity to the water heater before removing or opening the panels! Some electric water heater can have two thermostats, one each for the upper and lower heating elements. You may need to adjust both thermostats for best results.