Guide to Choosing the Best Thermostat for Hot Water Tanks

Like the cooling units in your house, the water heater consumes a high amount of electricity. Almost any cooling and heating appliances use a considerable amount of electricity. The best trick for saving electricity is to maintain the right temperature. Today, most water heater models include a thermostat.

But, how will you buy a new thermostat for ahot water tanks? Different brands have designed their thermostats for water heaters. Choosing the right heating elements may be challenging. So, we’ve provided a guide on how to pick a high-quality water heater thermostat.

Best Thermostat for Hot Water Tank – Our Top Picks

1. Zero Electric Water Heater Thermostat

Zero Electric Water Heater Thermostat

We’ve chosen a user-friendly and easily installable thermostat for electric water heaters. The copper heater element works with 240 Volts, while the wattage is 4500W. The length of the insert is 13-9/16″. The package includes a lower and upper heater element needed for your water heater.

According to users, installing this thermostat unit is easier than other similar devices. Still, you can rely on professionals for the solution. It’s a Therm-O-Disc Type device and is thermally responsive. Other advantages of Therm-O-Disc include higher reliability and optimal performance. Also, it has superb temperature-sensing capabilities.

  • Safe and durable
  • Includes a repair kit
  • Chrome coating on the heating element
  • Minor temperature-related issues

2. EWH-00 Electric Water Heater Thermostat

EWH-00 Electric Water Heater Thermostat

EWH-00 is a well-designed thermostat that provides you with energy-saving solutions. It’s compatible with most electric water heaters. The voltage for operating the thermostat is to be 120/240/480 VAC. There are KST series controls to meet water heater requirements for high electrical capacity.

The manufacturer has included a temperature-sensitive bimetal disc that regulates the snap action. The temperature is adjustable from 90 ℉ to 150 ℉. As there is a safety switch, you can avoid overheating issues. Make sure you use thermostatic mixing valves to prevent scalding risks.

The package includes a lower and an upper thermostat. Also, it’s a comprehensive package that comprises plumbers’ essentials. The copper water heating element will last a long time due to its chromed coating.

Additionally, the wrench and thermostat terminal protection covers are other kits added to the package. The wrench is made of quality steel, and there are cross-holes to help you use a screwdriver.

  • Built-in safety switch
  • Good temperature adjustment settings
  • Apcom style compatible
  • The reset button could be of higher quality.

3. WH10A Apcon Electric Water Heater Thermostat

WH10A Apcon Electric Water Heater Thermostat

You can choose this product if you’re looking for a thermostat for your upper element thermodisc. The settings help you adjust the temperature from 110 ℉ to 170 ℉. The slotted knob is also flexible. You can find the reset button is present near the gas valve.

Your water heater’s upper heating element works perfectly with the thermostat. Also, the thermostat is perfectly engineered to ensure flawless performance.

The thermostat sensor is made of metals and protects the system from frequent temperature fluctuations. Most users have claimed that it’s easy to install the thermostat: some holes in the wiring terminals enable the wires to be easily locked into place. Other advantages are limit control features that ensure safety.

  • Easy-to-use buttons
  • Includes safety features
  • High-temperature sensitivity
  • A bit costly

4. Rheem UV11699 Thermostat

Rheem UV11699 Thermostat

Rheem is another reputed brand with a reliable thermostat design for your water heater. It’s a corded electric device. So, check your power source before installing the thermostat.

The temperature can range from 150 to 170 degrees. The thermostat has universal parts and is available with a range of volts, such as 208, 240, 277, and 480V. You can also check the wiring diagrams to know the installation process for the lower and upper elements.

  • Best for indoor usage
  • Made from metal and plastic
  • Easy installation
  • No issues found

5. Rheem SP210246 Water Heater Thermostat

Rheem SP210246 Water Heater Thermostat

Made of high-quality plastic and metal, this water heater thermostat has a very sturdy construction. Installed indoors, the corded electric device has shown consistent performance. Users have raised no complaints against the design and functioning of the Rheem SP210246.

The installation process is also hassle-free. Whether you want lukewarm or extremely hot water, you can set the right temperature using this thermostat.

  • Lightweight design
  • Durable construction
  • Compatible with different water heaters
  • No complaint found

Which Thermostat Is Right for You?

Water heaters have different control components – the main one is the upper thermostat, which regulates the lower and upper heating elements. There is a temperature-activated button on every thermostat that triggers an element to heat your water if the water temperature is below the preset level. This is the major temperature-sensing function of the thermostat.

However, the thermostat doesn’t touch the water to identify the water temperature. The rear side of this device senses the hot water tank’s surface temperature. The contact between metals causes heat transfer to the thermostat due to the conduction process.

Many modern electric water heaters are available with two thermostats capable of sensing the water temperature. The upper one gives instructions to the lower thermostat.

Before purchasing a water heater thermostat, you have to know about various categories.

Electronic Thermostat

The electronic thermostat is a highly precise thermostat providing you with a range of options for water heater temperature adjustments. The thermistor is the main component designed to track temperature variations. A wire of the thermistor helps in measuring the temperature of your device. With a decline in temperature, there’s a decrease in resistance.

Stem Thermostat

A long stem in the thermostat expands with a rise in temperature. This expansion includes an upper limit to prevent water from exceeding the preset temperature. You’ll have no burning risks from it.

Bulb Thermostats

Capillary thermostats or bulb thermostats include a bulb full of heat-reactive fluid. The volume of this fluid increases due to heat. This increased volume lets the thermostat activate the heating component, managing heat production.

Bulb thermostats are found in many models such as automatic reset, manual reset, and double pole reset.

Smart Thermostat

If you’re looking for an innovative model, you can invest in a smart thermostat. Smart thermostats help you with an easy temperature adjustment for the water heater. You can program the heater using your mobile app. With this thermostat, you will receive energy usage updates, but the upfront cost of the thermostat is high.


How will I detect a faulty thermostat?

Check for a few signs in your malfunctioning thermostat. You’ll get normal cold water if the upper thermostat has any issues. It may also happen that the water isn’t very hot or the device can’t recover hot water quickly.

Sometimes, the water may become extremely hot if the temperature setting in your thermostat is very high. Improper calibration is also responsible for this problem.

Another potential issue is the tripping high-limit control or switch, meaning the reset button pops out.

How can I check the thermostat of my electric water heater?

After turning off the breaker of your heater, you have to detach the lower and upper panels using a flathead screwdriver. You may find an insulation cover on your thermostat. Remove and secure it properly.

Then, you have to set the highest temperature and control the multimeters. If you haven’t found any reading, it indicates defects in the thermostat. It is essential to check the lower thermostat as well.

Which is the most favorable water temperature to be set with the thermostat?

50 to 122 ℉ is the best temperature that you can set for your water heater. The input temperature is the most significant factor. Remember, electricity usage varies with the temperature difference between the thermostat setting and input water.

Where is the thermostat integrated into the water heater?

One thermostat of your heater is visible and adjustable, while the other can’t be viewable from the outside. The knobs in the settings are rotatable to let you adjust the temperature.


We have chosen the best thermostat for hot water tank models from different brands. While writing this review, we checked the feedback of different users. You may find slight differences in the design and features.

Depending on the thermostat you’ve chosen, there’s a variation in price. Install your thermostat properly to make the best use of the device. Compare our carefully chosen thermostats before making a purchase.

With years of experience under his belt, Adam decided to put his water heater knowledge to work. By providing high-quality content and expert guides, Adam hopes to help anyone looking for expert water heater advice.