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How to Adjust Your Water Heater to Save Energy

If you can make yourself a cup of tea just by turning on your faucet, you need to lower your water heater. You’ll help the planet and save money on your heating bills.


  • Step 1: Check your water temperature by holding a meat thermometer under the hot water faucet for a few minutes. If it’s over 120 degrees, it’s time to adjust the thermostat.
  • Step 2: Before you open up any part of an electric water heater, turn the power off! Water and 220 volts DO NOT MIX! Find your heater’s temperature control and set it to 120 degrees. Most electric heaters have two thermostats behind screw-on plates. Make sure the power’s off, and then set them to the same temperature. Oil heaters have a thermostat on the side, and gas heaters usually have one on the bottom.
  • TIP: If you have a furnace-fired oil water heater, do not tamper with the temperature. Lowering it would make your furnace less efficient.
  • Step 3: If your water heater is warm to the touch, it’s wasting energy. Help it keep that heat inside by having a water heater blanket installed. It will pay for itself by lowering your heating bills as much as 9%.
  • Step 4: Install a timer on your water heater so that it shuts off during times when you don’t need hot water, like the middle of the night.
  • TIP: Timers are not practical on gas heaters, which require a pilot light.
  • Step 5: Drain a quart of water from your tank every three months. It will remove sediment that reduces your heater’s efficiency. Follow the instructions for your heater.
  • Step 6: Periodically check the water temperature with the thermometer again—thermostats are often inaccurate. Adjust the thermostat and recheck the temperature until the water is really 120 degrees, regardless of what the thermostat says.
  • TIP: It’s not likely, but if you have a dishwasher without an internal heater, your water heater thermostat should be set to 140 degrees. 140 degree water is too hot for home use. Children, or elderly people without good feeling in their extremities can be badly scalded at 140 degrees. I recommend that this tip be deleted. Master Plumber speaking here. See this link:
  • Step 7: If you’re leaving your home for more than three days, turn the heater setting down to the lowest setting, or off if there’s no danger of the water freezing. Otherwise you’re paying to have hot water at the ready when no one’s around to use it.
  • Step 8: If your bills are still higher than they should be, consider replacing your water heater with a more energy-efficient one, like a solar heater, especially if yours is from before 1996. It will save you money in the long run—and it’s tax deductible!
  • FACT: Hot water is the third largest energy expense in your home, accounting for about 14% of your utility bill.

You Will Need

  • A meat thermometer
  • A water heater blanket
  • And a water heater timer

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