Lower water heater thermostat

For most homeowners, storage-type water heaters set above 120°F are simply using more energy without providing any additional benefits. One set to even 140°F can waste $36 to $61 annually in standby heat loss, and more than $400 in demand loss. Be sure to turn off electric, or turn down gas, water heaters when you go on vacation to avoid energy waste.

Skill level: Basic to advanced
Water heater thermostats are generally behind access panels. Many homeowners feel comfortable adjusting their thermostats, while some would rather leave it to a member of the family with greater skills.
Cost range: Free
Lowering your water heater thermostat is a do-it-yourself way to save energy and money.
Savings: Up to 9% in water heating costs
Keeping your electric water heater at 120°F will save about 9% of your water heating costs.