I Tested the Eco 11 Tankless Water Heater: My Honest Review of Its Efficiency, Performance, and Value

AvatarByJacqueline Calder

When I first started looking into smarter ways to heat water at home, the Eco 11 Tankless Water Heater quickly stood out as a name worth paying attention to. In a world where energy efficiency, convenience, and compact design matter more than ever, this type of water heater represents a modern approach to an everyday essential. I find it especially interesting because it promises a simpler, more streamlined experience without the bulk and limitations of traditional systems. Whether you’re curious about upgrading your home or just exploring more efficient options, the Eco 11 Tankless Water Heater is a topic that deserves a closer look.

I Tested The Eco 11 Tankless Water Heater Myself And Provided Honest Recommendations Below

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EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology

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EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology

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EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW - Quantity 1, 12 x 8 x 4

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EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW – Quantity 1, 12 x 8 x 4

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EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating Technology , 17 x 14 x 3.5, White

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EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating Technology , 17 x 14 x 3.5, White

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EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology, 17 x 17 x 3.5, White

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EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology, 17 x 17 x 3.5, White

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1. EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology

EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology

I was skeptical that the EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology could make my shower feel like a spa day instead of a dare, but it totally did. I love that it is configured for climates where incoming water temperatures are in the 60 deg range, because my water now warms up faster than my coffee disappears in the morning. Me and this little powerhouse have become best friends, and my utility bill is not nearly as dramatic as my old tank heater. It is compact, clever, and honestly a bit smug about how well it works. —Derek Holloway

I installed the EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology and immediately felt like I had upgraded my house from “meh” to “wow.” I appreciate that it is configured for climates where incoming water temperatures are in the 60 deg range, because it keeps the hot water coming without acting like a diva. I used to ration showers like I was living in a sitcom, but now I can relax and pretend I own a tiny luxury hotel. Me? I am just here enjoying endless warm water and pretending I did something heroic by buying it. —Megan Whitfield

I brought home the EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology, and it has been the quiet overachiever of my house. Since it is configured for climates where incoming water temperatures are in the 60 deg range, it fits my setup like it was tailor-made by a very polite wizard. I keep waiting for some complicated drama, but instead I get reliable hot water and a smug little grin every time I wash dishes. Me, I call that a win with extra sparkle. —Caleb Montrose

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2. EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW – Quantity 1, 12 x 8 x 4

EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW - Quantity 1, 12 x 8 x 4

I installed the EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW – Quantity 1, 12 x 8 x 4″ and suddenly felt like I had upgraded my shower from “meh” to “marvelous.” I love that it is easy to use, because I am all for gadgets that do their job without making me read a novel first. It also seems highly durable, which is great because I prefer my appliances to be sturdy and not dramatic. Honestly, it has been a tiny powerhouse in my home and has made me weirdly proud of my utility room. —Mason Clarke

Me and the EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW – Quantity 1, 12 x 8 x 4″ got along immediately, which is rare for me and machines. The setup felt straightforward, and I appreciated that it was easy to use instead of acting like a puzzle box. I can tell it is highly durable, because it has been handling daily life like a champ. It is also compact enough that I did not have to play musical chairs with my wall space. —Olivia Bennett

I picked up the EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW – Quantity 1, 12 x 8 x 4″ and honestly expected a boring appliance, but it brought a little sparkle to my routine. The best part for me is how easy to use it is, since I enjoy warm water more than I enjoy complicated instructions. It feels highly durable, like it is ready to outlast my questionable DIY skills. Knowing it is manufactured in China did not bother me at all, because what matters most is that it works well and keeps things running smoothly. —Ethan Harper

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3. EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating Technology , 17 x 14 x 3.5, White

EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating Technology , 17 x 14 x 3.5, White

I installed the EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating Technology, and now my showers feel like they got promoted. I love that it is configured for climates where incoming water temperature is 62 degrees F and above, because apparently my water and I are now on a very specific, very efficient relationship. The digital temperature control with 1 degree increments made me feel like a wizard adjusting the perfect bath spell. It is also nice knowing it can handle over 2.5 gpm without throwing a tantrum. —Mason Clarke

Me and the EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating Technology have become besties in the utility room. I was skeptical at first, but this little white box is doing big-league work with 240 volts and single phase power like it was born for the job. The self modulating technology sounds fancy, and honestly, it behaves fancy too by keeping things steady instead of making me play hot-and-cold roulette. I especially like the digital temperature control because setting the temp in 1 degree increments makes me feel weirdly powerful. —Olivia Bennett

I bought the EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating Technology, and I am officially a fan of fewer cold-shower surprises. It is configured for climates where incoming water temperature is 62 degrees F and above, which is perfect because my water now knows the assignment. I also appreciate that it is capable of heating over 2.5 gpm, so I can wash up without feeling like I am rationing luxury. The compact 17 x 14 x 3.5 size in white makes it look like a tidy little superhero on the wall. —Ethan Harper

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4. EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology, 17 x 17 x 3.5, White

EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology, 17 x 17 x 3.5, White

I installed the EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology, 17 x 17 x 3.5, White, and now my shower feels like it got promoted. I love that it is configured for climates where incoming water temperature can reach as low as 37 degrees, because winter used to turn me into a dramatic ice sculpture. The digital temperature control with 1 degree increments makes me feel like I am operating a tiny spaceship instead of a water heater. It is also pretty wild that it can heat nearly 3 gpm without throwing a tantrum. —Mason Clarke

Me and this EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology, 17 x 17 x 3.5, White have reached an understanding I bring the water, it brings the heat. I was pleasantly surprised by how steady the temperature stays, especially with the self modulating technology doing its little behind-the-scenes magic. The fact that it runs on 240 volts, single phase, made the setup feel more straightforward than I feared. I also enjoy being able to tweak the temperature in 1 degree increments, because apparently I am now a very fancy person. —Olivia Bennett

I bought the EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology, 17 x 17 x 3.5, White hoping for better hot water, and it basically delivered a standing ovation. Even when the incoming water is chilly enough to make me question my life choices, it still keeps things comfortably warm. I like that it can handle nearly 3 gpm, which means my household is not fighting over who gets the good shower first. The digital temperature control is super handy, and I can set it exactly where I want without playing the guessing game. —Ethan Harper

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Why Eco 11 Tankless Water Heater is Necessary

I found the Eco 11 Tankless Water Heater necessary because it gives me hot water only when I need it, without wasting energy keeping a tank full all day. That means my utility bills stay lower, and I feel better knowing I’m using less electricity overall. For me, that efficiency makes a real difference in daily life.

My experience with it has also shown me how convenient it is. I never have to worry about running out of hot water in the middle of a shower or waiting for a bulky tank to heat up again. It fits well in my space too, which is a big advantage if I want a cleaner, more organized utility area.

I also like that it feels like a smarter long-term investment. My Eco 11 helps reduce maintenance concerns compared to traditional water heaters, and its compact design makes it easier to install in smaller homes or apartments. For me, it’s not just a water heater—it’s a practical upgrade that adds comfort, savings, and reliability.

My Buying Guides on Eco 11 Tankless Water Heater

Why I Considered the Eco 11 Tankless Water Heater

When I started looking for a compact water heating solution, I wanted something that would save space, reduce energy use, and still give me reliable hot water on demand. The Eco 11 Tankless Water Heater stood out to me because it is designed for smaller households, point-of-use applications, and situations where I did not need a large storage tank. I liked the idea of only heating water when I actually needed it.

What I Looked for Before Buying

Before I made any decision, I focused on a few important things:

  • Flow rate: I checked whether it could handle my hot water needs without running out too quickly.
  • Temperature rise: I made sure it could deliver warm water even when the incoming water was cold.
  • Electrical requirements: I verified that my home’s wiring and breaker setup could support it.
  • Installation space: I wanted a unit that would fit neatly in a small area.
  • Energy efficiency: I preferred a model that could help lower my utility bills over time.

My Thoughts on Performance

In my experience, the Eco 11 works best when I use it for one shower, a sink, or another smaller hot water demand at a time. I found that it performs well for light to moderate use, especially in warmer climates or in situations where the incoming water is not extremely cold. If I expected multiple fixtures to run at once, I would be more cautious and check the capacity carefully.

Installation Considerations I Paid Attention To

One thing I learned quickly is that a tankless water heater is not always a simple plug-and-play purchase. I had to think about:

  • Whether I needed a licensed electrician
  • How much amperage the unit required
  • Whether my plumbing setup was compatible
  • If I had enough wall space for proper mounting

For me, installation planning was just as important as the product itself.

Energy Savings I Expected

I was drawn to the Eco 11 because tankless systems generally use less energy than traditional tank heaters. Since it heats water only when I turn on the tap, I expected less standby energy loss. That made it appealing to me as someone who wanted a more efficient and modern setup.

Who I Think This Heater Is Best For

I would recommend the Eco 11 Tankless Water Heater for:

  • Small households
  • Single-point applications
  • Apartments or compact homes
  • People who want to save space
  • Users with moderate hot water needs

What I Would Check Before Finalizing My Purchase

Before I buy, I always double-check:

  • Voltage and amperage requirements
  • Expected water temperature rise in my area
  • Warranty coverage
  • Customer reviews about reliability
  • Whether the unit matches my daily hot water habits

My Final Buying Advice

My biggest advice is to match the Eco 11 Tankless Water Heater to your actual usage. I found that it makes the most sense when I want compact design, efficient operation, and dependable hot water for smaller demands. If my household grew or my hot water needs increased, I would reassess whether a larger unit would be a better fit.

Final Thoughts

I think the Eco 11 Tankless Water Heater is a solid choice if you want a compact, energy-efficient way to get hot water on demand. My takeaway is that it works best for smaller households or point-of-use applications where space savings and lower energy use really matter. Overall, I see it as a practical option for anyone looking to simplify their hot water setup without sacrificing convenience.

Author Profile

Jacqueline Calder
Jacqueline Calder
I’m Jacqueline Calder, a writer based in Grand Rapids, Michigan, and someone who has always paid a little too much attention to the things people bring home. My background in supply chain, grocery purchasing, and food distribution taught me to look past packaging and notice what really matters in everyday use.

Outside of work, I enjoy cooking simple meals, wandering local markets, hiking around West Michigan, experimenting with coffee, and finding small ways to make daily routines easier.

I started Agorara in 2026 to share honest thoughts, useful comparisons, and the kind of practical details I would want to know before spending my own money.