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How to Adjust Your Water Heater Temperature in 6 Simple Steps

Writen by Ronald Brown

Fact checked by Natalie Bridges

how to adjust your water heater temperature

Do you tend to change the temperature on the electric water heater regularly? If so, you might find it tricky at first. Water temperature plays a significant role in our household water supply. A water heater should not be too cold to allow bacterial infiltration and not too hot to generate scalding hot tap water.

We need to adjust hot water heater temperature to accommodate different household water activities that require particular thermal settings. In this tutorial, I will cover the DIY tools you will need alongside the comprehensive ways how to adjust your water heater temperature. Let’s start!

Table of Contents

What Will You Need in This Tutorial


Before you make the water hotter on the electric water heater, you should know the basic safety guidelines to keep your family safe.

The Occupational Safety and Health Administration (OSHA) strongly recommends keeping our water heater at 140 degrees Fahrenheit to reduce the risk of contracting Legionella Disease.

However, The Centers for Disease and Control (CDC) and US Environmental Protection Agency (EPA) advise homeowners to keep their water heater tank at 120 degrees Fahrenheit or lower. It is to prevent domestic hot water scalds and reduce energy consumption.

The consensus of professionals is to turn down your water heater temperature to a safe and comfortable temperature setting. The optimal water heater temperature is between 130-140 degrees Fahrenheit, depending on your preference and hot water needs.

If you have small children, it is best to set your water heater at 120 degrees Fahrenheit. Alternatively, you could adjust the temperature as needed (as long as you don’t get lower or higher than the expert-approved levels.)

Now that you have a better understanding of the importance of maintaining a proper water heater temperature, you are one step away from finishing this task. You need the following tools to adjust the electric water heater temperature successfully :

  • Phillips Screwdriver and a Flat-head Screwdriver – Most appliances incorporate these two typical screw heads. You would need a #0 Phillips screwdriver to unlock the cover plate of an electric water heater that houses the thermostat.
  • Electrical Safety Gloves – You need one pair of electrical-insulating gloves because they have dielectric material that will protect you from electric shocks.
  • Remember, electrical heating elements become susceptible to failure over time. Therefore, wearing hand protection gloves is your first line of defense against electrocution.
  • Multifunction Kitchen Thermometer – There are different models of thermometers for various purposes. Hence, you should select one suitable for use in hot water.
  • Generally, a standard digital multipurpose kitchen thermometer is all that you need. But I would recommend buying an instant-read digital thermometer (if you don’t have a kitchen thermometer yet) because it lives up to its name. It provides a precise degree of heat within just a few seconds.
  • Jug/Cup – You can either use a jug or a cup. Both can be used as storage vessels for hot water. Still, I prefer using a jug because it has a larger, deeper body than a cup to accommodate and store hot water more securely.

Step By Step Instructions


Step 1: Check the current temperature of your water heater

As discussed earlier, we regulate electric water heater temperature control according to our household needs and conditions.

First, we need to inspect the temperature of our water heater to ensure that it caters to our hot water demands.

  • Prepare the jug, then open the nearest hot water faucet.
  • Fill the jug with enough hot water to test.
  • Then, immerse the stem of your kitchen thermometer in the water and keep it in place until the temperature stops rising.

The thermometer should read at least 120 degrees Fahrenheit. If the reading isn’t what you expect it to be, you may now proceed to adjust the water heater temperature.

Pro Tip: If you have an immunocompromised family member at home, it’s safer to set the water heater temperature at 140 degrees Fahrenheit.

Step 2: Switch off the power supply of your electric water heater

  • Wear your safety gloves for safety first.
  • Then go to the main electric service panel of your home and find the circuit breaker of your water heater. It is typically labeled and runs at around 30-50 amps. Flip the breaker to the “OFF” position.

Pro Tip: Before turning off the power supply, stay beside your water heater and listen to the “hissing sound”. It indicates that your unit is using electricity.

After turning off the circuit breaker, check if you can still hear the sound. If the power is off, you won’t hear it anymore.

Step 3: Remove the faceplate of your water heater to access the thermostat

Most dual-element electric water heaters use two thermostats and two heating elements. They are inside the panels installed at the side of your water heater tank: the upper thermostat and the lower thermostat.

  • Using the Phillips screwdriver, open the two thermostat screw-on covers. Make sure to put the screws in a safe place to prevent misplacing them given their minuscule size.
  • Lift the plate, and you will see an insulation pad underneath.
  • Wear your gloves again because wires surround the thermostat. Peel back the insulation carefully and set it aside as you need to replace it later.

Pro Tip: If you do not know how to locate and access the two thermostats, refer to the user’s manual to save time and energy.

Step 4: Adjust the temperature dial to your preferred setting

After removing the insulation, you just gained full access to your thermostats. The temperature dial is easy to spot. Look for a rotating knob with a screw slot (usually white) beneath the reset button (the red one).

Most electric models feature a white triangle indicator that points to the spot of the labeled temperature levels. Using your flat head screwdriver, adjust the dial to your desired temperature. Remember to convert both of the thermostats to the same amount.

Step 5: Reassemble the access covers.

Put the insulation back in its place and secure the metal plates with the screws you extracted earlier.

Step 6: Restore the electric supply to your water heater and test the water temperature

  • Turn the circuit breaker of your water heater back to the “ON” position. Again, don’t forget to wear your safety gloves. Wait for three to four hours to get the newly adjusted hot water.
  • Re-examine the water temperature. Repeat the first procedure. Open the nearest hot faucet for a minute to alleviate the pressure and fill the jug with a generous amount of hot water.
  • Use the kitchen thermometer to check the temperature. If it matches the temperature you selected in the dial, then you are good to go. You may now enjoy the constant supply of ideal hot water for your family.

Otherwise, if the temperature is still not satisfactory, follow the previous steps 2-5 until your water is at the perfect temperature.


Learning how to adjust your water heater temperature is as easy as switching the lights on and off, provided that you follow safety precautions. Always follow the recommended temperature of water heater experts.

If your unit exhibits sudden temperature fluctuations or similar issues, don’t panic and consult a professional plumber right away. For any questions, feel free to fill them in the comment box below!

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