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Electric water heaters are an essential household appliance so when they stop working as expected, it can be quite frustrating.

If the thermostat in your water heater has become faulty, it may need to be replaced. We dive into what you need to know when replacing your water heater thermostat. For most electric water heaters, we recommend the Rheem SP20060 Electric Water Heater Tune-Up Kit.

Note: For replacing gas powered water heater thermostats, it is recommended to utilize the services of a professional.

At SmartHomePerfected we always advise readers not to undertake any work they are not competent in performing and if in any doubt, it is best to seek the assistance of a professional.

How Does a Water Heater Thermostat Work?

Generally, an electric water heater incorporates three main elements that include a thermostat, a heating component, and a stop or reset switch that prevents the whole unit from excessive heat.

A water heater thermostat is used to regulate warm water within the heater. An electric water heater with a capacity of around 30 gallons makes use of two heating elements, and each of them has a thermostat. The one on top (with a high limit switch) is used as a primary thermostat while the lower one observes the changes in the water temperature.  Both thermostats have different features and function differently.

As for heaters with a low storage capacity, a single water heater thermostat and heating element is used to control the temperature.

Things You Need to Know

Voltage of Your Water Heater

If you feel like your electric water heater may have a problem, the first thing you should consider doing is to check its power. Please note that if you are not confident enough to read or work with electrical power or voltages, you should call a professional to fix it for you.

Mostly, water heaters are designed to operate on 240 volts. Some of the single element water heaters function on 120 volts while others may use 240 volts. However, you can check the voltage reading on a label attached to the heater.

Number of Elements in Your Water Heater

There are typically two elements in your electric water heater – an upper element placed up high and a lower element located at the bottom of the heater. As mentioned, electric current flows through each of these elements, as a result, they heat up and raise the temperature of the water stored inside the tank.

Replacing the Thermostat

There can be two reasons when you feel that your thermostat needs to be replaced – either it’s broken or not doing its job.

When the upper thermostat fails, your heater stops working or doesn’t produce the hot water. When the lower one fails, only the upper half of the water tank remains warm. It’s rare to witness both of them fail at the same time. However, it is recommended to replace them both when one fails.

Types of Water Heater Thermostats

You will find single and dual element thermostats on the market. A single element thermostat system, as the name indicates, uses a single heating element to control the temperature of the entire tank.

A dual water heater thermostat, on the other hand, makes use of the two heating elements placed at the top and bottom of the tank.

This electric water heater tune-up kit helps you renew or repair an electric water heater system as it comes with a complete set of thermostats and heating elements.

Top Features
  • Patented resistored technology has been used to increase the life of the heating elements and tank

  • Thermostats feature a temperature-sensitive bimetal disc

  • Energy-efficient, ensures uniform heat distribution, and delivers long-lasting performance

This Electric Water Heater Tune-Up Kit from Rheem comes with all the key parts needed to replace the faulty items on your electric water heater. The replacement process is quick and easy for a person who can follow the instructions correctly.

The kit includes both upper and lower thermostats (one Therm-O-Disk 240-volt lower thermostat and one Therm-O-Disc upper thermostat). Besides, it packs two patented resistored heating elements (240V/4,500W High Watt Density elements with gaskets), that provide enhanced corrosion protection, extending the life of both the water tank and the elements.

Both copper and plastic have been used for the construction of these replacement parts and they are quite durable.


These thermostats and heating elements can be used to replace the faulty parts of a variety of brands that include American, AO Smith, General Electric, GS Wood, Bradford White, Craftmaster, Maytag, Mor-Flo, Kenmore, Lochinvar, State, Whirlpool, Reliance, and Sears water heaters.

The product is UL and CSA listed for safety and comes with one year of warranty. All in all, the Rheem SP20060 Electric Water Heater Tune-Up Kit features a great set of thermostats and elements that not only restore your electric water heater to a peak condition but also are reliable enough to keep it running for years.

What we liked
  • Suitable for most of the brands and fits easily
  • Installation is easy and takes a little time
  • Comes with one year warranty
What we didn't like
  • The kit is more expensive than purchasing the individual replacement thermostat
Top Features
  • A dual-element standard Therm-O-Disc upper thermostat that operates on 240 Volts

  • Features a temperature range of 90-degree to 150-degree

  • Equipped with a high limit switch that trips at 170 degrees

This is another dual element electric water heater thermostat from Rheem that can be used with ordinary residential electric water heaters. These heaters feature a non-simultaneous design, meaning only one element remains ‘on’ at any given time.

The thermostat employs a limit switch that shuts it off at 170-degree to prevent overheating. Its thermostat differential should be between 17°F to 27°F.

The Rheem UV11698 Electric Water Heater Thermostat fits all the major brands that include Rheem, Ruud, Richmond, General Electric, Kenmore, AOSmith, Bradford White, Craftmaster, GS Wood, Lochinvar, Mor-Flo, Reliance, State, Whirlpool, and many others.

Top Features
  • Equipped with a temperature-sensitive bi-metal snap-action disc

  • Has a manual reset switch to prevent overheating

  • Energy-efficient temperature range settings, ranging from 90-degree to 150-degree

The Rheem SP11695 Therm-O-Disc Style Lower Thermostat is an ideal choice for dual-element residential electric water heaters. It can be used to replace APCOM-style thermostats in your electric heaters.

Like the upper thermostat above, this is also an energy-efficient thermostat that features an adjustable temperature range and delivers excellent performance at high electrical loads.

Thanks to the metal and plastic construction, this lower thermostat is quite durable and comes with a one year warranty period. Furthermore, like other Rheem thermostats on the list, it can also work with all the popular water heater brands.

Top Features
  • Adjustable energy-efficient settings, ranging from 110F to 160F

  • To help prevent overheating, a safety switch has been included

  • For easy replacements, a manual with detailed guidelines and diagrams is provided

This is the final product in our list of some of the most reliable water heater thermostats. It has been designed for single element applications and can be used to replace both APCOM and most Thermo-O-Disc style water heater thermostats.

The Camco 07843 thermostat can be adjusted to the desired temperature settings. It packs a lot of other features that help it deliver solid performance and make it power-efficient. Moreover, the installation process is easy and the thermostat can fit most of the common brands.

Common Questions

What is the Correct Temperature Range for my Water Heater?

When you get a new water heater, its maximum temperature is typically preset to 140-degree Fahrenheit. Some people say it’s an ideal value, while others may disagree and reduce the temperature down to 120 degrees.

The American Society of Sanitary Engineering and the US Department of Energy recommend that your water heater temperature should be set to 120° F. This not only saves your energy but also reduces the chances of mineral buildup in your pipes.

Although a higher temperature may involve the risk of scalding, the Occupational Safety and Health Administration (OSHA) declares that 140 degrees is safer. This basically kills a particular form of bacteria known as Legionnaires' disease bacteria, which may cause some serious sickness like pneumonia

How to Replace Your Electric Water Heater Thermostats?

Before you replace your old water heater thermostat with a new one, it’s not necessary to drain the water out of the tank. Follow the instructions below to safely replace the water heater thermostat.

How to Check Your Water Heater Power?

To check the power of your water heater, you’ll need a multimeter. The process is super-easy and takes a few minutes. Check out the video for step by step instructions.

How to Test Your Water Heater Thermostat?

As mentioned, most water heaters use two thermostats: an upper thermostat and a lower thermostat. Here you’ll learn how to test them to make sure they both are working without any issues. Before you start the testing process, keep a multimeter, a Phillips head screwdriver, safety gloves, and shoes with you.

Why Does my Water Heater Reset Button Trip?

If the “Reset” button on your water heater keeps tripping, it’s most likely that the water inside the tank is getting too hot and the cause can be a bad or a faulty thermostat.

Thermostats control the heating elements and use them to warm the water when it’s cold or shut them off when the water reaches the maximum temperature value.

However, when these thermostats get damaged or faulty, they remain in the “on” position and never turn the heating elements off. As a result, water gets extremely hot and trips the high-limit switch. The problem can be fixed by testing the thermostats and replacing the faulty one.

A shorted heating element, loose electrical connections, and a faulty high-limit switch are some of the other reasons that can also trip the “Reset button”.

The Verdict

Water heater thermostats are some of the most essential parts of an electric water heater. 

In our opinion, the Rheem SP20060 Electric Water Heater Tune-Up Kit is the best deal to get your electric water heater back up and running.

This electric water heater tune-up kit helps you renew or repair an electric water heater system as it comes with a complete set of thermostats and heating elements.

Top Features
  • Patented resistored technology has been used to increase the life of the heating elements and tank

  • Thermostats feature a temperature-sensitive bimetal disc

  • Energy-efficient, ensures uniform heat distribution, and delivers long-lasting performance

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1 Comment

  • Raymond P Vecchione
    Posted November 5, 2021 at 2:19 pm

    Just had an maraton 75 gal hot water installed and found that the upper thermostat was set to medium but the lower is set to low. On my old rheem/rudd they were both set to the same setting 125 deg. Can you tell me how these settings should be set to get the best operation. Thank you in advance, ray v

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