How To Adjust Temperature On Rheem Water Heater [Explained]

When you are wondering how to adjust temperature on Rheem water heater, then we can assure you it’s quite simple. Just follow the below steps to adjust the temperature:

  • Start by turning off the power supply.
  • Locate the access panel of the thermostat and pull the insulation.
  • Adjust the thermostat temperature screw with a flathead screwdriver.
  • Set your desired setting and that’s done!

However, go on reading if you want to learn the temperature adjustment procedure in detail. 

how to adjust temperature on rheem water heater

How To Adjust Temperature On Rheem Water Heater [9 Easy Steps]

We know how much it’s challenging for you to ensure a very delicate balance while adjusting the water temperature on Rheem and any other electric hot water heater.

This is because the higher temperature will be responsible for more power consumption. On the other hand, a too lower temperature will boost the growth of Legionella and other microorganisms.

rheem water heater

However, the steps below will help you to adjust the temperature on your Rheem electric hot water heater efficiently:

Step 1: Check The Current Temperature

Before changing the water heater temperature, you should know the current temperature of your hot water at the tap. It will give you a better idea of how much you’ll need to adjust the heater.

check the current water temperature

Most water heaters have a built-in temperature gauge with a readout. Without this, you can also check the water temp with a standard cooking thermometer.

But before that, you have to calibrate your thermometer. To do so, take a cup of ice water and hold the thermometer on it until the temp goes down to 32 degrees.

While the thermometer is resetting, turn on the hot water faucet closest to the heater. Allow the water to flow until it reaches the maximum temperature.

Then fill a cup with hot water and insert the thermometer in the cup of hot water.

Ensure the probe is fully submerged. Wait 30-60 seconds and then check the temperature at the meter.

Step 2: Manage The Tools

Now that you know the current temperature of your water heater, it is time to adjust the settings as your desired. To do so, first, you’ll have to manage a few simple tools. For instance:

  • Phillips screwdriver.
  • Or, a small flat-head screwdriver.
  • Noncontact circuit tester.

Step 3: Turn Off The Power Supply

For the first step, you have to shut off the power supply to your water heater. Head to your house’s central circuit breaker. Find the breaker from the panel where your Rheem water heater is connected. Just flip the breaker switch to the “Off” position.

turn off the power supply

Right then, the electricity flowing to the unit will cut off. While dealing with the circuit breaker, make sure you’re standing to the side of the breaker panel. Standing off to one side prevents your body from the brunt of any released sparks or electrical charge.

Step 4: Remove The Front Access Panel

After turning off the power supply, move to your Rheem water heater. Now locate the thermostat’s access panel. Most larger electric water heaters have two thermostats. One is the upper one and another is the lower thermostat. The smaller units have only one thermostat.

remove the front access panel of your rheem water heater

Anyway, in this step, you have to open the access panels. You will find the panel sealed with four screws, two screws at the top and bottom of the panel. Take a flat-blade screwdriver and loosens them.

Now remove the screws and place them in a safe place. Then pull the panel from the unit.

Once the front panel is removed, make sure that the power to the unit is with the use of a noncontact circuit tester. Though you’ve tuned the breaker off, there is a high chance of a power supply there. So, you need to be careful about that.

Step 5: Pull Out The Insulation Covering The Thermostat

After removing the front panel, you will find a thicker layer of insulation concealing the inner thermostat. It reduces heat loss and also ensures more accurate temperature readings from the heater. Now simply pull out the insulation from the cavity and set it aside.

pull out the insulation covering the thermostat

In most cases, you’ll find a plastic guard beneath the metal access panel. Wiggle the plastic cover a bit to disengage it from the connection.

Step 6: Adjust The Temperature Setting

Now you will need a flat-blade screwdriver to adjust the temperature setting. After de-assembling the access panel, you will find high- and low-end temperature ranges at the thermostat.

But the configuration of the thermostat is different from model to model. This is because if you have two thermostats, you’ll notice a resettable high-limit switch in the same place.

adjust the temperature setting

Anyway, right below the high-limit switch, you will find the thermostat screw. Now, insert the screwdriver into the slot on the thermostat dial and start rotating to set your desired temperature.

Rotate it counterclockwise to decrease the temperature and right or clockwise to increase it. Now if you have dual heating elements, set the low thermostat temperature in the same way.

Step 7: Reassemble The Access Panel

Once the temperature setting is done, replace the insulation, plastic cover, and access panel back the way you found it. Secure the panel with the screws using the screwdriver. Make sure you’re not over-tightening it as it may harm the metal panel.

Step 8: Restore Power To Your Water Heater

Now, flip the circuit breaker back “ON” position. Ensure there is a fluent electric supply to the water heater. It will take a little time for your water heater to reach your set temperature.

Step 9: Test Your Water Temperature

Finally, you can test your water temperature for assuming that everything is going well. Check the water temperature as the previous way.

Fill a cup with hot water and insert any of the standard cooking thermometers and then check the temperature.

If the reading isn’t showing at the recommended level, be sure your water heater is going through some malfunctions that need your attention. You can troubleshoot it by yourself or better to call in a certified technician to handle the task.

What Temperature Should Your Rheem Electric Hot Water Heater Be Set To

You have to set your electric water heater at the correct temperature range. When you’re setting it too low like under 120 degrees Fahrenheit, it leads to bacterial growth.

Besides, raising the temperature above 140 degrees Fahrenheit enhances the chances of scalding the skin and also increases utility bills. So, it’s best to set the temperature within the range of 120 to 140 degrees Fahrenheit.

1. Lowest Safe Temperature:

Most of us are favorable to using very hot water. But here you must be concerned about the kids, you’ve around the house. If you’re setting the temperature at 140° Fahrenheit, it’ll take only 5 seconds to scald the skin.

Thus, Consumer Product Safety Commission (CPSC) recommends setting the temperature to no more than 120 degrees Fahrenheit or 49 degrees Celsius.

Also, raising the temperature increases your home’s energy consumption by 14-18%, for why you may encounter higher utility bills. Only a 10°F reduction will save you from 3-5% energy consumption.

2. Highest Safe Temperature

The more you’re lowering the temperature, the more increase the risk of creating bacteria like legionella, E. coli, and staphylococcus. Legionella is responsible for causing Legionnaire’s disease.

According to the Occupational Safety & Health Administration (OSHA), water heaters should be set at least 140 degrees Fahrenheit.

So, it’ll be highly better if you are setting the temperature between 120 to 140 degrees Fahrenheit or 49 to 60 degrees Celsius.

3 Factors That May Affect Water Temperature

There are dozens of things that may affect your water heater temperature. Let’s one some major ones and how to tackle them:

1. The Distance From The Water Heater To The Outlet

If there are too long distances between the water heater and the faucet outlet, it’ll take too long time to reach warm water to you.

That means, the longer water is traveling, the more cold water will discharge at that time before the hot water appears. As a solution, you can do the followings:

  • Install the water heater closer to the faucet outlet as much as you can. Instead, you can install a recirculation system which will prevent to sit hot water in pipes to get cold. It creates a loop between the water heater and the faucet that keeps the water warm.
  • Alternatively, you can use a secondary water heater right to the outlet, it will heat the cold water left in the pipe.

2. Pipe Diameter

Secondly, faulty plumbing fixtures are the culprit itself in case of delay in heating water. Higher chances are the pipes used for the water heater are too big in diameter.

Too big a pipe diameter decreases the flow rate for why the hot water fails to rush through the pipe, affecting the water temperature. As a solution, you need to reduce the diameter of your hot water pipes.

3. Faulty Water Heater Elements

If still, you can’t get the right temperature even after adjusting the thermostat, be sure your heater is going through some major malfunctions.

Either the heating element is worn out or the thermostat stops working. It’s highly recommended to head to a certified plumber to tackle these situations.

3 Major Rheem Electric Water Heater Temperature Problems [Get Easy Solutions]

Most often, users encounter several temperature issues while operating the water heater which is really annoying. To diagnose these problems, you must have to know the actual reasons behind these issues.

rheem electric water heater temperature problems

If you are wondering about some effective DIY electric hot water heater repair, here are the most common water heater problems with potential fixes:

i). Water Is Not Getting Hot Enough

When you find your Rheem water heater isn’t producing enough hot water, but the heater is operating normally, be sure there are a number of reasons behind this problem.

Higher chances are heater unit is too small that fails to meet your household’s hot water demand. Other major reasons include:

  • Setting the temperature too low.
  • Damaged or displaced dip tube.
  • A leak from the hot water heater.
  • Faulty heating elements.
faulty heating elements of rheem water heater

In most cases, sediment builds up in the bottom of the tank is enough to lower the efficiency of the heater, resulting in lukewarm water through the hot water faucets.

How To Fix:

Before moving to the other repair, it is a good idea to check whether the thermostat is set too low. Turn up the temperature on the thermostat with a flathead screwdriver.

If still the same situation, inspect the heating elements for any damage. It may become inefficient after long years using. Replace the worn-out heating element.

Also, make sure the dip tube is not damaged or displaced from its place. It’s better to contact a water heater technician to replace the bad dip tube.

On top of all the above, you should be more concerned about regular draining and flushing your hot water tank. Sediment build-up in the tank and heating element reduces the heat transfer to the water heater.

Don’t miss checking whether there is any leak in your tank.

After ensuring all the DIY steps, your hot water heater should return to its standard temperature. If not, you may need to upgrade your hot water tank with the larger one.

ii). No Hot Water

Not having hot water from your Rheem water heater is the most common issue that users often encounter. If it electrically operated heater, the lack of hot water is a clear sign of a tripped circuit breaker due to power surges.

Also, blown fuses, loose wiring connections, a faulty thermostat, tripped high-temperature limit, and using an undersized water heater tank are major causes of the problem if no hot water runs in your house.

How To Fix:

Here are the simple fixes in case of the no hot water issue in a water heater:

  • First, reset the breaker in case it gets tripped. Just flip the breaker to the “ON” position.
  • Also, check for blown fuses and loose wiring. Fix them.
  • If the breaker is fine, inspect the high-temperature limit if it has switched off on the water heater itself. You can repair it by pressing the reset button and the power will return to the water heater.
  • Faulty heating elements may also be the cause of your problem. In that case, you have to replace the bad elements.
  • While doing so, check the thermostat function whether it is in well-working order. If not, contact professionals to service your water heater.
  • Besides all repairs, they will better suggest whether you’ll need to upgrade your water heater according to the demand of your family members.

iii). The Water Temperature Is Too High

Too much hot water is a clear indication that the thermostat is not functioning well. Either the heater’s thermostat may be set too high or it is broken. 

check the continuity of the thermostat

Other major reasons include failing heating elements due to sediment effect, and blocked or malfunction of the pressure relief valve.

How To Fix:

Start troubleshooting by checking the temperature dial on your water heater. Lower the temperature if it’s set too high. Besides, make sure that the thermostat is sensing temperature correctly.

In such cases, you can test the conductivity of the thermostat using a multimeter.

Then inspect the heating elements for any corrosion and sediment buildup around them. Call an expert if you find deterioration in the elements.

Also, make sure your water heater is free from any hard mineral deposits. Flush and drain your water heater tank at least once a year.


What Precautions Should You Take When Adjusting Your Water Heater Temperature?

Before adjusting the temp, first, ensure that you’ve flipped off the breaker to the off position. Secondly, make sure that you aren’t setting the temperature at a scalding level, that’s quite dangerous.  

Are 130 degrees too hot for a water heater?

The recommended water heater temperature is between 120 to 140°F. so, turning up the temperature to 130 degrees is completely a safe level, especially for larger water heaters. Consider below 130 degrees if you have a small unit.

Does outside temperature affect the water heater?

Yes! If there is chilly cold outside, the water heater has to work harder to reach the set temp level.  Insulating your hot water heater is the best way to tackle this situation. It will reduce heat loss, keeping the inside water warm.

In Closing!

Ensuring the proper adjustment of the heater temperature is quite essential to get the highest comfort while using hot water. It will not only save you from extra costs on utility bills but also from serious scalding.  

Well! That’s all here about how to adjust the temperature on Rheem’s electric water heater. Hope that there should be no confusion left on this fact. Still, if you want to know more, just let us know through comments.

About William

William is the founder of He has real life practical skills in fixing smoker & heating appliance issues. He loves to share his knowledge & helps others in fixing their appliances & saving their money. William firmly believes that anyone can repair his or her unit with the correct guidance & knowledge. See more at about us.

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