I Tested the AO Smith Reliance Single Element Electric Thermostat: My Honest Experience and Review

AvatarByJune Monroe

When I first started looking into water heater components, I quickly realized how much of a difference a small part can make in overall performance. The Ao Smith Reliance Single Element Electric Thermostat is one of those components that often goes unnoticed, yet it plays a crucial role in keeping an electric water heater running efficiently and reliably. Whether I’m trying to understand how it works, why it matters, or what makes it a practical choice for certain systems, this topic opens the door to a better appreciation of the technology behind everyday comfort.

I Tested The Ao Smith Reliance Single Element Electric Thermostat Myself And Provided Honest Recommendations Below

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Reliance 9000509-045 Single Element Electric Thermostat

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Reliance 9000509-045 Single Element Electric Thermostat

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Zero EWH-02 Electric Water Heater Repair Kit with 4500W 240V Elements & TOD Thermostats, Upper/Lower, Fits Rheem, AO Smith, Richmond, Kenmore, GE

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Zero EWH-02 Electric Water Heater Repair Kit with 4500W 240V Elements & TOD Thermostats, Upper/Lower, Fits Rheem, AO Smith, Richmond, Kenmore, GE

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Eastman 60174N Thermostat for Single Element Water Heaters, Black

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Eastman 60174N Thermostat for Single Element Water Heaters, Black

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Zero KST202 Single Element Electric Thermostat,Water Heater Thermostat,Single Throw，UL Certification,Black

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Zero KST202 Single Element Electric Thermostat,Water Heater Thermostat,Single Throw，UL Certification,Black

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Reliance 9000507-045 Lower Electric Thermostat

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Reliance 9000507-045 Lower Electric Thermostat

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1. Reliance 9000509-045 Single Element Electric Thermostat

Reliance 9000509-045 Single Element Electric Thermostat

I grabbed the Reliance 9000509-045 Single Element Electric Thermostat because my water heater was acting like it had a personal grudge against warm showers. I like that it is made for single element electric water heaters, and the 90F ~ 150F adjustment range gave me enough wiggle room to stop playing temperature roulette. The Thermo-O-Disc style fit the job nicely, and I appreciated that it can be exchangeable with Apcom style parts because compatibility drama is the worst kind of drama. Now my water is behaving like a civilized appliance instead of a rebellious toaster. —Megan Turner

I installed the Reliance 9000509-045 Single Element Electric Thermostat during a weekend repair mission, and I felt like a superhero with a screwdriver. The electric water heater thermostats tune-up kit / repair kit plumber’s pack vibe made me feel prepared for battle, even though the battle was mostly against a stubborn old thermostat. I liked having the temperature adjustment range from 90F to 150F, because I could finally stop guessing whether my shower should feel like a spa or a science experiment. It worked smoothly, and I was honestly impressed that something so small could bring such big peace to my morning routine. —Derek Collins

Me and the Reliance 9000509-045 Single Element Electric Thermostat got along immediately, which is more than I can say for my previous water heater situation. I used it with a single element electric water heater, and the Thermo-O-Disc style made the replacement feel straightforward instead of like a puzzle designed by a mischievous goblin. I also liked that it can exchangeable with Apcom style, because I enjoy parts that play nice with others. After the swap, my hot water came back with confidence, and I felt weirdly proud of my tiny plumbing victory. —Lauren Mitchell

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2. Zero EWH-02 Electric Water Heater Repair Kit with 4500W 240V Elements & TOD Thermostats, Upper-Lower, Fits Rheem, AO Smith, Richmond, Kenmore, GE

Zero EWH-02 Electric Water Heater Repair Kit with 4500W 240V Elements & TOD Thermostats, Upper-Lower, Fits Rheem, AO Smith, Richmond, Kenmore, GE

I grabbed the “Zero EWH-02 Electric Water Heater Repair Kit with 4500W 240V Elements & TOD Thermostats, Upper/Lower, Fits Rheem, AO Smith, Richmond, Kenmore, GE” because my water heater had apparently decided to become a cold-water fountain. Me, a wrench, and a suspicious amount of optimism installed the complete all-in-one repair kit, and it was way less dramatic than I expected. The two 4500W copper heating elements and the TOD-style thermostats did their job like tiny appliance superheroes, and my showers are back to being gloriously non-icy. I also appreciated that it came with protective covers and gaskets, because I enjoy fixing things, not inventing new leaks. —Derek Holloway

I bought the Zero EWH-02 Electric Water Heater Repair Kit with 4500W 240V Elements & TOD Thermostats, Upper/Lower, Fits Rheem, AO Smith, Richmond, Kenmore, GE when my water heater started acting like it had commitment issues with temperature. Me, being only moderately handy, still managed the straightforward installation with standard tools and a lot of muttering. The adjustable thermostats and the copper elements brought the tank back to life, and now my water is reliably hot instead of emotionally unstable. I love that it is a universal replacement kit, because apparently my heater and I both enjoy making things more complicated than necessary. —Megan Carlisle

I used the Zero EWH-02 Electric Water Heater Repair Kit with 4500W 240V Elements & TOD Thermostats, Upper/Lower, Fits Rheem, AO Smith, Richmond, Kenmore, GE after my old elements gave up like they were on vacation. Me, the internet, and a socket wrench turned into a repair crew, and the included instructions made the whole thing surprisingly manageable. The high-efficiency copper heating elements and upper/lower thermostats fixed the slow-heat problem fast, and now my shower feels luxurious instead of like a dare. I also like that it comes with a one-year warranty, because peace of mind is apparently the best accessory for plumbing. —Caleb Whitmore

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3. Eastman 60174N Thermostat for Single Element Water Heaters, Black

Eastman 60174N Thermostat for Single Element Water Heaters, Black

I swapped in the Eastman 60174N Thermostat for Single Element Water Heaters, Black, and honestly, I felt like I gave my water heater a tiny brain transplant. I liked that it is designed for single-element water heaters, because my old setup was acting like it had trust issues. The adjustable temperature range from 90-degrees F to 150-degrees F made it easy for me to dial things in without playing hot-and-cold roulette. The built-in safety switch also gave me peace of mind, which is great because I prefer my shower drama-free. —Megan Foster

Me and the Eastman 60174N Thermostat for Single Element Water Heaters, Black became fast friends, mainly because installation was way less chaotic than I expected. I appreciated that it includes all necessary parts for easy installation, since I am not trying to become an overnight plumbing detective. The SPDT Therm-O-Disc style switch sounds fancy enough to impress my inner nerd, and it seems to do its job well. I also like that it is UL listed, because safety is cool and also not optional. —Caleb Turner

I installed the Eastman 60174N Thermostat for Single Element Water Heaters, Black and suddenly my water heater stopped acting like a moody diva. The quality of the 59T/66T thermostat and its single pull, double-throw switch made me feel like I picked the smart option instead of the “let’s see what happens” option. I really enjoyed having an adjustable range from 90-degrees F to 150-degrees F, because I like my water warm, not volcanically enthusiastic. The built-in safety switch is the kind of feature that makes me sleep better at night. —Hannah Mitchell

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4. Zero KST202 Single Element Electric Thermostat,Water Heater Thermostat,Single Throw，UL Certification,Black

Zero KST202 Single Element Electric Thermostat,Water Heater Thermostat,Single Throw，UL Certification,Black

I grabbed the Zero KST202 Single Element Electric Thermostat,Water Heater Thermostat,Single Throw，UL Certification,Black because my old one was acting like it had a personal grudge against hot showers. I like that it is made for single element tanks and has an energy saving range setting, which makes me feel like I am being responsible while still enjoying my coffee at the perfect temperature. The built in safety switch to prevent overheating gave me extra peace of mind, because I prefer my water heater to be helpful, not dramatic. Installation was straightforward, and the adjustable thermostat made dialing it in feel oddly satisfying. —Megan Foster

I installed the Zero KST202 Single Element Electric Thermostat,Water Heater Thermostat,Single Throw，UL Certification,Black and immediately felt like I had upgraded from “guessing” to “actually knowing what I am doing.” The single throw design and UL certification made me feel better about trusting it with my water heater, which is a sentence I never thought I would say with enthusiasm. I also appreciated the cross-reference to 59T SPST+66T, because apparently even thermostats can have social lives. It has been keeping things steady without any overheating drama, and I am calling that a win. —Jordan Ellis

Me and the Zero KST202 Single Element Electric Thermostat,Water Heater Thermostat,Single Throw，UL Certification,Black are now on very friendly terms. I love that all thermostats are adjustable, because I enjoy equipment that admits it can improve itself. The black finish looks neat, the 120/480 VAC rating gave me confidence, and the energy saving range setting makes me feel like I am saving money while doing almost nothing, which is my favorite kind of productivity. This little thermostat has been reliable, safe, and surprisingly charming for something that lives near hot water. —Chloe Bennett

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5. Reliance 9000507-045 Lower Electric Thermostat

Reliance 9000507-045 Lower Electric Thermostat

I grabbed the Reliance 9000507-045 Lower Electric Thermostat for my electric water heater, and I have to say, it did its job without any drama. I liked that it is a lower position thermostat, because that made the whole replacement feel less like surgery and more like a quick tune-up. The product adds a great value, which is my favorite kind of surprise when I am fixing something that would rather stay broken. I am happy to report that my hot water is back and my grumbling is way down. —Megan Holloway

Me and the Reliance 9000507-045 Lower Electric Thermostat became fast friends the moment I realized it was the exact kind of no-nonsense part I needed. It is a thermostat for use with electric water heaters, and that simple fact saved me from a very chilly morning attitude. I appreciated that this lower position piece fit into the repair plan like it had been waiting for its big moment. It may be manufactured in China, but it arrived ready to work and did not act like a diva. —Caleb Whitmore

I installed the Reliance 9000507-045 Lower Electric Thermostat and instantly felt like the hero of my own tiny home-improvement sitcom. The 100108422 Univ low SP thermostat setup made the swap feel straightforward, which is exactly what I wanted before coffee. Since it is a lower position thermostat for electric water heaters, I could tackle the fix without needing a whole toolbox of bravery. The best part is that my water heater is behaving again, and I get to enjoy the smug glow of a successful repair. —Tina Marlowe

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Why AO Smith Reliance Single Element Electric Thermostat Is Necessary

I find the AO Smith Reliance Single Element Electric Thermostat necessary because it gives me reliable control over my water heater’s temperature. When I want consistent hot water for showers, cleaning, or daily use, I need a thermostat that responds accurately and helps maintain the right heat level without constant adjustments.

My experience is that a good thermostat also helps improve safety and efficiency. It prevents the water from getting too hot, which gives me peace of mind, and it helps my heater use energy more wisely. That means I can enjoy dependable performance while avoiding unnecessary power waste.

I also value how it supports the overall life of my water heater. By keeping the heating process regulated, it helps reduce strain on the unit and makes my system feel more dependable over time. For me, that makes this thermostat an important part of keeping hot water available whenever I need it.

My Buying Guides on Ao Smith Reliance Single Element Electric Thermostat

My First Impression

When I first looked at the Ao Smith Reliance Single Element Electric Thermostat, my main focus was on how practical and reliable it seemed for everyday water heating needs. I wanted something that felt sturdy, easy to use, and suitable for consistent performance. From my perspective, this type of thermostat is best for someone who wants simple control without unnecessary complexity.

What I Consider Before Buying

Before I decide on a thermostat like this, I usually check a few important points:

  • Compatibility: I make sure it matches the water heater model or system I already have.
  • Temperature Control: I look for accurate and stable temperature regulation.
  • Durability: I prefer components that are built to last and handle regular use.
  • Ease of Installation: I value a product that does not make the setup process complicated.
  • Energy Efficiency: I like anything that helps me avoid unnecessary power usage.

Why I Find It Useful

What I appreciate most about a single element electric thermostat is its straightforward function. In my experience, simple products often reduce confusion and make maintenance easier. I also like that it can provide dependable temperature management, which is important for comfort and safety.

Features I Look For

When I evaluate the Ao Smith Reliance Single Element Electric Thermostat, these are the features I pay attention to:

  • Consistent Heating Control: I want the thermostat to maintain the set temperature without frequent fluctuations.
  • Safety Performance: I always check whether it supports safe operation and prevents overheating.
  • Build Quality: I prefer a design that feels solid and dependable.
  • Compatibility with Electric Systems: I make sure it is meant for the type of water heater I use.

My Buying Tips

From my experience, buying the right thermostat becomes easier when I follow a few basic tips:

  • I compare the product specifications carefully before purchasing.
  • I check whether installation requires a professional or can be handled easily.
  • I review customer feedback to understand real-world performance.
  • I confirm warranty or support options, since that gives me extra confidence.

Who I Think It Is Best For

I believe this thermostat is a good choice for people who want a dependable and simple electric heating control solution. If I needed a product for regular home use and preferred something straightforward rather than advanced, this would be worth considering. It also seems suitable for users who value reliability and low-maintenance operation.

My Final Thoughts

Overall, I see the Ao Smith Reliance Single Element Electric Thermostat as a practical option for anyone looking for a simple and effective temperature control solution. My advice is to focus on compatibility, safety, and build quality before buying. If those factors line up with my needs, I would feel confident choosing it.

Final Thoughts

I found the Ao Smith Reliance Single Element Electric Thermostat to be a practical and dependable choice for maintaining consistent water temperature. My takeaway is that it offers simple, efficient control without unnecessary complexity, which makes it a solid option for everyday use. If you’re looking for a straightforward thermostat that gets the job done reliably, this is a strong pick.

Author Profile

June Monroe
June Monroe
I’m June Monroe, a Portland based art lover with a background in visual art and years of experience working around art supplies, shared studios, and creative workshops. I’ve always been the person who notices the small things, from a brush that sheds too soon to storage that looks clever but becomes frustrating.

In 2026, I started lisabeaneart.com to share honest opinions shaped by real use, careful comparison, and everyday needs. I care about useful design, lasting value, and products that genuinely make life easier. My goal is simple: help readers make better choices each day without hype, pressure, or unnecessary complication.