APPLIANCES & LIGHTING

Reducing Water Heating Costs

Practical tips and appliance upgrades for saving energy on your home's hot water usage, the second largest energy expense in most homes.

2 min read Updated Aug 19, 2026 DataWisdom
Lower the Temp, Save Energy
Optimize the 2nd Largest Expense

In this guide

  • Adjust your water heater temperature
  • Install low-flow fixtures
  • Insulate pipes and tanks
  • Wash clothes in cold water
  • Consider a heat pump water heater

You can reduce water heating costs by lowering the tank's thermostat to 120°F, installing low-flow fixtures to reduce hot water usage, insulating older tanks, washing clothes in cold water, or upgrading to a highly efficient heat pump water heater.

The second largest energy expense

Water heating accounts for roughly 18% of the average home's energy consumption, making it the second largest energy expense after central space heating and cooling. Because it runs year-round, optimizing your water heating system offers massive savings potential.

Lower the thermostat

Many water heaters are set to 140°F at the factory. The U.S. Department of Energy recommends lowering this to 120°F. For every 10ºF reduction in temperature, you can save 3% to 5% on your water heating costs. Lowering the temperature also reduces the risk of scalding and slows mineral buildup in your tank.

Reduce hot water consumption

The simplest way to lower water heating costs is to use less hot water. The less you use, the less your appliance has to heat.

  • Low-flow fixtures: Install WaterSense-labeled showerheads and faucet aerators. They maintain pressure while drastically reducing the gallons-per-minute (GPM) used.
  • Cold water washing: Modern laundry detergents are designed to perform exceptionally well in cold water. Switching from hot to cold washes eliminates the energy required to heat the wash water.
  • Full loads: Only run your dishwasher and washing machine when they are completely full.

Insulate your tank and pipes

Standard storage water heaters suffer from standby heat loss—the water cools down while sitting in the tank, forcing the heater to turn on and reheat it even when no one is using hot water. Insulating the first few feet of pipes entering and exiting the heater, and adding an insulation blanket to older tanks, can reduce standby heat losses by 25% to 45%.

Standby Loss Reduction
Energy saved by slowing thermal transfer from the tank to the ambient room air.

Definitions

  • Standby Loss: Energy wasted maintaining the temperature of unused water.

Example

If standby losses account for $80 of your annual bill, a $20 insulation blanket that halves those losses pays for itself in six months.

Upgrade to a heat pump water heater

If your electric water heater is nearing the end of its life, replacing it with a heat pump water heater (hybrid water heater) is one of the most lucrative energy investments you can make. Instead of using electrical resistance to create heat, they act like a refrigerator in reverse—extracting ambient heat from the air and pumping it into the water tank. They are typically two to three times more efficient than standard electric water heaters.

Limitations

Check your tank's manual before installing an insulation blanket; modern tanks already have high levels of internal insulation, and adding a blanket could void the warranty or cover critical safety valves. Additionally, heat pump water heaters require adequate clearance and pull heat from the surrounding room, which slightly cools the space they are installed in.

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APPLIANCES & LIGHTING QUESTIONS

Frequently Asked Questions

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WHAT YOU WILL FIND HERE

  • Direct explanations
  • Short illustrative calculations
  • Links to relevant calculators and guides
What is the ideal temperature for a water heater?
The Department of Energy recommends setting your water heater to 120°F. Many manufacturers set them to 140°F by default. Lowering the temperature saves energy and prevents scalding.
Do low-flow showerheads really save money?
Yes. A low-flow showerhead reduces the volume of water you use. Less water used means your water heater has to use less energy to heat replacement water.
What is standby heat loss?
Standby heat loss occurs when the hot water sitting inside a storage tank naturally cools down over time. The heater must turn on periodically to reheat the water, even if no hot water is being used.
How much does a heat pump water heater save?
Heat pump water heaters are up to three times more efficient than standard electric resistance water heaters, often saving hundreds of dollars a year in electricity costs.
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NEXT STEP

Evaluate Your Washing Machine

See how much electricity your washing machine uses. Remember that washing in cold water eliminates the water-heating portion of the cost entirely.