Should You Lower the Temperature of Your Water Heater in the Summer?

By Sarah Stasik

June 28, 2025

Fun-in-the-sun season has arrived, and while there's a lot of good splashing in the pool, it's everything you can do to keep your home interior cool and refreshing. The AC is humming, and ceiling fans are spinning — all the while you're keeping an eye on the energy bills. Will they rise as high as the summer heat wave?

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One appliance many people overlook during such times is the water heater. You might want the hottest of water for steamy baths and warming showers midwinter, but do you need it cranked up to the same temp in July?

You might wonder whether a lower water heater temperature in summer can make a difference for utility efficiency. The short answer is yes. Find out more about energy-efficient summer settings for your water heater below.

Is It More Energy-Efficient to Lower Water Heater Temperature in Summer?

Yes, it’s typically more energy-efficient to lower your water heater temp in summer. When outdoor temperatures rise, your water heater doesn’t have to work as hard to maintain hot water, so reducing the water heater temp in summer might help you save energy. Lowering the temperature by just 10 to 20 degrees can cut standby heat loss and reduce utility bills.

What Is the Rationale Behind That?

Your water heater works by keeping a tankful of water hot, even when you’re not using it. The constant heating uses energy, especially when the water cools and needs to be reheated.

In the winter, cold air and incoming cold water make the heater work harder. But in the summer, the water entering the tank is often already warmer, so it takes less energy to heat it. The ambient temperature around the unit may also be warmer, so the unit doesn't have to work as hard to heat the water.

By adjusting the water heater temperature for summer, you reduce how often the unit has to kick on — and that saves energy.

What Is the Best Water Heater Temperature Setting for Summer?

The best water heater temperature setting for summer is typically around 120 degrees F (49 degrees C). This is warm enough to meet most household needs — like showers, dishwashing and laundry — while reducing energy use and the risk of scalding.

If your water heater is set higher in the winter (like 130 degrees F or more), lowering it in the summer can help you save without sacrificing comfort. Just make sure everyone in your home still gets hot water when needed, and don’t go too low — especially if you use a dishwasher without a built-in heater.

How Much Can You Save By Lowering Your Water Heater Temperature?

According to the Department of Energy, lowering your water heater temperature from 140 degrees F to 120 degrees F can lead to 4% to 22% in energy savings annually. Savings may be as much as $400 (CAD 558) annually.

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Does Lowering Water Heater Temp Affect Hot Water Supply?

Yes, lowering your water heater temperature can affect your hot water supply — but usually only if you lower it too much. At 120 degrees F, most households still get plenty of hot water for everyday tasks like showers, laundry and washing dishes.

However, if your home has a high demand for hot water or your water heater is undersized, lowering the temperature could mean running out of hot water faster. If that happens, consider raising the temp slightly or staggering high-usage activities. For instance, you might spread family showers throughout the day or run the washing machine in the middle of the day.

How Low Is Too Low?

Avoid setting your water heater temp below 120 degrees F. Temperatures under this threshold increase the risk of bacterial growth.

How Do I Adjust My Water Heater Temperature?

First, turn off power to the unit at the breaker. If you have a gas water heater, set the gas control to "pilot." You can open the access panel door for electric water heaters with a screwdriver to adjust the thermostat. Gas models typically have a temperature dial you can set.

You can power up the water heater once you make the adjustment. Wait a few hours to test the water at the tap to ensure it's a comfortable and correct temperature.

All CAD conversions are based on the exchange rate on the date of publication.

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