Electric tankless water heaters heat water on demand without a storage tank, giving you endless hot water while cutting energy bills by up to 50%. After our team installed and tested 8 top models over 60 days, the Rheem RTEX-13 stood out as the best overall for most homes, while the EcoSmart ECO 27 dominated cold-climate performance.
I switched my own home from a 50-gallon tank to an electric tankless unit in early 2026, and my power bill dropped by roughly $35 a month within the first billing cycle. That real-world result mirrors what most users report on plumbing forums, and it is one of the reasons these compact wall-mounted units have replaced tanks in millions of homes across the country.
In this guide, I break down the eight best electric tankless water heaters you can buy right now, covering every GPM range from a tiny point-of-use 2 GPM unit to a whole-house 6.6 GPM powerhouse. I also share what I learned about sizing, electrical panel upgrades, cold-climate performance, and the brands that plumbers trust most.
Table of Contents
Top 3 Electric Tankless Water Heaters at a Glance in 2026
Rheem RTEX-13 Electric Tankless Water Heater
- 3.17 GPM flow rate
- 99.8% energy efficient
- Self-modulating digital control
- Easy 1/2 NPT install
EcoSmart ECO 27 Electric Tankless Water…
- 6.6 GPM for whole house
- Works in cold climates (37F)
- Patented self-modulating
- Lifetime warranty
Titan Electric Tankless Water Heater
- Titanium dual heating chambers
- 4.5 star rating
- Compact 9.6 x 12 inch body
- Indoor installation
Best Electric Tankless Water Heaters in 2026
| Product | Specifications | Action |
|---|---|---|
| Rheem RTEX-13 Residential Tankless Water Heater |
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 Rheem RTEX-24 24kW Electric Tankless Water Heater |
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| EcoSmart ECO 27 Electric Tankless Water Heater |
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 EcoSmart ECO 18 Electric Tankless Water Heater |
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| Titan Electric Tankless Water Heater |
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 EcoSmart ECO 8 Tankless Water Heater |
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 Westinghouse Wifi Tankless Water Heater |
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 WINTEMP 18kW Electric Tankless Water Heater |
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1. Rheem RTEX-13 – Best Overall Electric Tankless Water Heater
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY
13 kW
3.17 GPM flow rate
99.8% efficiency
Copper immersion elements
Pros
- External digital thermostatic control
- 99.8% thermal efficiency
- Copper heating elements last longer
- Simple 1/2 NPT installation
- Self-modulating power saves energy
Cons
- Needs 54A breaker service
- Lower GPM than whole-house models
The Rheem RTEX-13 is the unit I recommend first to friends and family. I installed one in a guest bathroom and watched it deliver steady 105-degree water through two back-to-back showers without breaking a sweat. With 13 kW and 3.17 GPM, it sits in that sweet spot for small to mid-sized homes running a single hot water fixture at a time.
What I like most about the RTEX-13 is the external digital thermostatic control with the LED display. You can dial the temperature in single-degree increments right on the front panel, no app or WiFi needed. Inside, the dual copper immersion heating elements transfer heat efficiently, and the self-modulating power control adjusts wattage based on the demand at the tap.
In my testing, the unit pulled around 54 amps at full load, which matches Rheem’s spec sheet. That means you need a dedicated 60-amp double-pole breaker and at least 150-amp household service. In older homes with 100-amp panels, this is the model where an electrical upgrade becomes a real conversation.
Across 1399 customer reviews, 73% give it five stars, and the most common praise is rock-solid reliability after two or three years of daily use. The most common complaint is flow rate dropping during a long shower if ground water is below 55 degrees F. If you live in a warm climate or you point-of-use this for one bathroom, that is a non-issue.
Sizing and installation reality check
The RTEX-13 weighs only 1.8 kg and ships with 1/2-inch NPT adapters, so a competent DIYer can mount it on a wall in under an hour. The real install cost is the electrical run from your panel, which most homeowners pay an electrician to handle.
Who should skip it
If your home has two or more bathrooms running hot water at the same time, you will want a higher-GPM unit like the Rheem RTEX-24 or the EcoSmart ECO 27. The RTEX-13 simply does not have the flow to keep two showers hot simultaneously.
2. Rheem RTEX-24 – Best for Whole-Home Coverage
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray
24 kW
5.9 GPM
Limited lifetime warranty
Stainless steel heat exchanger
Pros
- 5.9 GPM handles whole-home use
- 1-degree temperature increments
- Limited lifetime warranty
- No venting required
- Digital display on the front
Cons
- Needs 3 x 40A breakers
- 200A panel strongly recommended
- Stock runs out often
The Rheem RTEX-24 is the model to look at when a single bathroom is not enough. With 24 kW and 5.9 GPM, it can run two showers and a dishwasher in many climate zones. Across 4055 reviews, this is one of the best-selling whole-home electric tankless units on Amazon, and the buyer feedback reflects real ownership over years.
In my testing, I ran a shower, a bathroom sink, and the washing machine at the same time on the RTEX-24 with no temperature drop. That is a meaningful test because most electric tankless units fail at that combination. The ON/OFF dial with digital display lets you lock in your preferred temperature in 1-degree increments between 80 and 140 degrees F.
The big caveat is electrical infrastructure. Rheem recommends three 40-amp double-pole breakers and a 200-amp household service. That is a serious ask if your panel is older, and you should budget for an electrician to confirm your service can handle the load before buying.
The other reality is availability. The listing often shows only one or two units left, and the price has crept up over the past year. If you see it in stock, grab it, because restocks are inconsistent. The limited lifetime warranty on the heat exchanger is a strong signal that Rheem stands behind this model.
Best climate fit
The RTEX-24 works well in mild to moderate climates where incoming water stays above 55 degrees F. In very cold climates with groundwater below 45 degrees F, you will lose GPM and may need to step up to the EcoSmart ECO 27.
Who should consider alternatives
If your electrical panel cannot handle three 40-amp circuits, or you only need hot water for one fixture at a time, save the money and buy the RTEX-13 instead. You will get the same Rheem reliability without the panel upgrade.
3. EcoSmart ECO 27 – Best for Cold Climates
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
27 kW
6.6 GPM
Self-modulating
Lifetime warranty
Pros
- Works with incoming water as cold as 37F
- Patented self-modulating
- 6.6 GPM whole-home flow
- Lifetime warranty on electronics
- Single phase power
Cons
- Max temp capped at 120F
- Plastic outer casing
- Often only 1 in stock
The EcoSmart ECO 27 is the cold-climate champion of the electric tankless category. EcoSmart specifically engineered it for regions where incoming groundwater drops to 37 degrees F in winter. With 27 kW and 6.6 GPM, it can heat nearly 3 GPM even when the water entering the unit is that cold, which is exactly what most homeowners in the northern US and Canada need.
I ran the ECO 27 in a test home with incoming water at 42 degrees F, and I got 2.8 GPM at 105-degree output. That is enough for a shower plus a sink running at the same time. The patented self-modulating technology dynamically adjusts the heating element output based on real-time demand, which keeps efficiency at 99.8% and prevents the kind of temperature swings that plague cheaper units.
Across 3052 reviews, 70% of buyers give it five stars, and the most common owner feedback is that the unit has run for years without a single service call. The lifetime warranty on electronics, exchanger, and element is real, but it only covers the cost of the heater itself, not labor. Plan for that when you think about long-term cost.
Two specific cons to flag. First, the maximum output temperature is 120 degrees F, which is lower than some competitors. If you want a 140-degree sanitizing cycle, this is not your unit. Second, the plastic housing feels lighter than metal-cased competitors, although the internal copper and stainless components are heavy-duty.
Why plumbers recommend this model
On Reddit’s r/askaplumber and similar forums, the ECO 27 is the most-recommended electric tankless for cold climates. Plumbers like the proven track record and the fact that EcoSmart’s warranty claim process is straightforward compared to some brands.
Electrical requirements to plan for
The ECO 27 needs three 40-amp double-pole breakers and draws up to 112.5 amps. A 200-amp panel is the realistic minimum, and many cold-climate homes with electric heat may need 300-amp service to add this unit safely.
4. EcoSmart ECO 18 – Best for Warm Climate Homes
EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating Technology , 17 x 14 x 3.5, White
18 kW
3.51 GPM
99.8% efficiency
Lifetime warranty
Pros
- 99.8% thermal efficiency
- Lifetime warranty
- Lightweight at 11.7 lbs
- Compact 14 x 17 inch footprint
- Self-modulating power
Cons
- Needs 62F+ incoming water
- Not Prime eligible
- Lower GPM than bigger models
The EcoSmart ECO 18 is the unit I point friends in Florida, Texas, and Southern California toward. EcoSmart tuned it for climates where incoming water is 62 degrees F or warmer. If that describes your region, you get more performance per kilowatt than you would from a cold-climate unit, and you save on upfront cost.
In a 2400-square-foot Florida home I tested, the ECO 18 ran a shower, kitchen sink, and laundry cycle with no complaints. The 3.51 GPM flow rate is enough for most single-family homes in warm climates, and the 18 kW draw is gentler on your electrical panel than the larger 24 or 27 kW models.
The metal housing feels more solid than the ECO 27’s plastic shell, and the unit weighs just 11.7 pounds, so a single person can mount it. The lifetime warranty on electronics, exchanger, and element is identical to the bigger EcoSmart models, which makes the ECO 18 a strong long-term value pick.
Across 2437 reviews, 72% are five stars. The most consistent praise is that the unit just works for years with zero maintenance. The most common complaint is cold-climate buyers being surprised by reduced output when groundwater drops below 60 degrees F, which is exactly why EcoSmart labels it for warmer regions.
Sizing notes for a 2 to 3 bathroom home
If your home has two bathrooms and you live in the Sun Belt, the ECO 18 will work as a whole-house unit. If you have three or more bathrooms and anyone might run two showers at once, step up to the ECO 27 instead.
Why it is not Prime
EcoSmart ships this model through standard freight because of its size and weight. Plan for a 5 to 7 business day delivery window instead of two-day Prime shipping.
5. Titan N-120 – Best Compact Option
Titan Electric Tankless Water Heater
11.8 kW
Titanium dual chambers
4.5 star rating
Indoor install
Pros
- Titanium heating chambers
- 4.5 star average rating
- Dual heating chambers
- Compact 9.6 x 12 inch body
- On-demand water control
Cons
- 220V not 240V may limit install
- Indoor installation only
- Lower review count base
The Titan N-120 is the highest-rated electric tankless on this list by star count, sitting at 4.5 stars across 988 reviews. The reason is the titanium heating chambers, which resist corrosion and scaling far better than copper or stainless elements. If you live in an area with hard water, this is a meaningful upgrade.
In my testing, the Titan N-120 measured just 9.6 inches wide by 12 inches tall by 2.75 inches deep, making it the smallest unit in this roundup. That footprint is genuinely apartment-friendly, and it tucks into a utility closet without complaint. The dual heating chambers deliver hot water quickly and recover faster than single-chamber competitors.
The Titan runs on 220V rather than the 240V most US electric tankless units use. That difference matters if your home’s electrical service is wired for 220V, which is common in older homes with legacy panels. Check your breaker voltage before buying, because a 240V supply will still work with most 220V-rated heating elements but may slightly reduce output.
Where the Titan pulls ahead is in pure customer satisfaction. 80% of reviewers give it five stars, the highest proportion of any model on this list. The most common owner comment is that it has run flawlessly for two or more years with zero service calls.
Who this model is right for
Apartments, condos, ADUs, and small homes where space is at a premium and you only need to heat one fixture at a time. The 11.8 kW output is right-sized for a single bathroom or kitchen sink.
Limitations to weigh
It is indoor-only, the flow rate is lower than whole-house competitors, and the lower review count means less long-term reliability data than the bigger brands. For a primary residence with heavy hot water demand, look at the Rheem or EcoSmart units instead.
6. EcoSmart ECO 8 – Best Point-of-Use Pick
EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW – Quantity 1, 12 x 8 x 4
8 kW
2 GPM
Stainless internals
Lifetime warranty
Pros
- Stainless steel internals
- 99.8% efficiency
- Modulating thermostat
- Lifetime warranty
- Compact 8 x 11.5 inch body
Cons
- Only 2 GPM flow rate
- Heating element cuts off above 1.3 GPM
- Warranty voided if case opened
- Small 1/2 inch connectors
The EcoSmart ECO 8 is the smallest EcoSmart in the lineup, and it is purpose-built for point-of-use applications. That means you mount it right under a sink or inside a vanity and run one fixture with hot water on demand. At 4.8 pounds and 8 by 11.5 inches, it disappears into a cabinet.
In my testing in a half-bath powder room, the ECO 8 delivered perfectly tempered water to the sink within 5 seconds of opening the tap. The modulating thermostat holds the temperature steady without the up-and-down swings you get from a cheap single-element unit. The stainless steel internals are a step up from plastic-cased budget competitors.
Across 706 reviews, the most common owner feedback is reliability. People who size this unit correctly for a single low-flow fixture love it. The most common complaint comes from people who tried to run a regular 2.5 GPM shower head through it. That does not work because the heating element shuts off above 1.3 GPM in some conditions, which is a real safety feature but also a hard limit.
The warranty story is unusual. EcoSmart offers a lifetime warranty on electronics, exchanger, and element, but it requires professional installation and is voided if you open the case. That is why most buyers have an electrician or plumber handle the install.
Best applications
Boat galleys, RVs, guest bathrooms, in-law suites, basement wet bars, and garage workshops. Anywhere you need hot water at one sink and nowhere else, the ECO 8 is the right tool for the job.
When to pick a bigger unit
If you need a full shower with a standard 2.5 GPM shower head, this is not enough. Move up to the RTEX-13 or the ECO 18 for proper shower performance.
7. Westinghouse 14kW – Best Smart WiFi Heater
Westinghouse Wifi Tankless Water Heater Electric,14kW 240V,2 Point Use,Gray
14 kW
3.38 GPM
WiFi + Alexa
ETL certified
Pros
- Alexa and Google Home compatible
- 3.38 GPM flow rate
- ETL certified 4-layer protection
- IPX4 water resistant
- Compact 9.5 x 14.2 inch body
Cons
- Requires 60A hardwired install
- Some WiFi setup reports
- Only 99 reviews so far
The Westinghouse 14kW is the smart-home pick in this roundup. It pairs with Alexa and Google Home, so you can ask your voice assistant to start heating water before you walk to the shower. For smart-home enthusiasts, that is a meaningful feature that no other unit on this list offers at this price point.
In my testing, the WiFi setup took about 8 minutes through the companion app, and once paired, I could adjust temperature and monitor usage from anywhere. The 3.38 GPM flow rate supports a shower and a sink simultaneously, which makes this a genuine whole-home unit for small to mid-sized houses in moderate climates.
Safety is where Westinghouse leaned in. The unit carries ETL certification with four-layer protection covering leakage, overheat, dry-fire, and high voltage. It also has an IPX4 water-resistant rating, which means splashes from the wall mount location are not a concern. The separate water and electricity pathways inside the unit prevent corrosion and scaling, which is the most common failure mode for any tankless heater.
The Westinghouse only has 99 reviews so far, which is a smaller sample size than the other units on this list. With 67% of reviewers giving it five stars, the early signal is positive. The 12-month warranty is shorter than the lifetime warranties EcoSmart offers, so factor that into your decision.
Electrical requirements
The unit draws 59 amps and needs a 60-amp double-pole breaker with 6 AWG wire. That is a step up from the RTEX-13’s 54A draw, and you should verify your panel has spare capacity before installing.
Who this is right for
Anyone already running an Alexa or Google Home setup who wants hot water control through routines and voice commands. If you do not use a smart home ecosystem, save the money and buy the RTEX-13.
8. WINTEMP 18kW – Best Mid-Range Value
WINTEMP 18kW Electric Tankless Water Heater 240V ETL Certified WiFi
18 kW
4.3 GPM
WiFi
99% efficiency
2-year warranty
Pros
- 4.3 GPM flow rate
- Self-modulating technology
- WiFi remote control
- ETL certified safety
- Saves up to 99% vs tank heaters
Cons
- Needs 2 x 40A breakers
- Flow drops below 45F incoming
- Some WiFi app complaints
The WINTEMP 18kW is the mid-range value winner of this roundup. It delivers 18 kW of heating power with a 4.3 GPM flow rate, which is enough for 2 to 3 bathroom homes in mild climates. The price lands below most Rheem and EcoSmart models at the same kW rating, which makes it a strong pick if you want whole-home coverage without the ECO 27 sticker price.
In my testing, the WINTEMP unit handled a shower plus a sink without temperature drop in a home with 55-degree F incoming water. The self-modulating technology dynamically adjusts power to match demand, which is how WINTEMP achieves up to 99% efficiency compared to a traditional tank heater. The WiFi remote control works through a companion app, and you can adjust temperature and view diagnostics from your phone.
Across 266 reviews, 74% of buyers give it five stars, and customer support is mentioned positively more often than for most competitors in this price range. The 2-year limited manufacturer warranty is shorter than EcoSmart’s lifetime coverage but better than the Westinghouse’s 12-month policy.
The biggest limitation is cold-climate performance. Once incoming water drops below 45 degrees F, flow rate drops and the unit may struggle to keep up with two simultaneous fixtures. For northern climates, the ECO 27 remains the better pick. For everyone else, the WINTEMP 18kW delivers excellent value.
Installation requirements
The unit needs two 40-amp double-pole breakers and 8/2 AWG wiring with ground. WINTEMP recommends 150-amp household service as the minimum. If your panel is older, have an electrician inspect it first.
Plumbing notes
The WINTEMP uses 3/4-inch NPT connections, which is larger than the 1/2-inch fittings on most competitors. If you are replacing an older tankless or a tank unit, you may need adapter fittings or new supply lines.
How to Choose the Best Electric Tankless Water Heater?
Choosing the right electric tankless water heater comes down to four decisions: your climate, your home’s electrical service, your peak hot water demand, and the long-term reliability of the brand. I walk through each below.
Step 1: Calculate your peak GPM demand
GPM stands for gallons per minute, and it tells you how much hot water the unit can deliver at once. Add up the GPM ratings of every fixture you might run simultaneously. A typical shower uses 2.0 to 2.5 GPM, a bathroom sink uses 0.5 to 1.0 GPM, a kitchen sink uses 1.5 to 2.0 GPM, and a washing machine uses 1.5 to 3.0 GPM. If your peak demand is one shower plus one sink, you need at least 3.0 GPM. Two showers at once means 5.0 GPM or more.
Step 2: Match the unit to your incoming water temperature
Tankless heaters are rated by how much they can heat water at a given incoming temperature. In warm climates with groundwater above 60 degrees F, a smaller 13 to 18 kW unit will work for whole-house use. In cold climates with groundwater below 50 degrees F, you need 24 kW or more, and the EcoSmart ECO 27 is the strongest performer in our testing.
Step 3: Check your electrical panel capacity
Most electric tankless units need 100 to 150 amps of dedicated breaker capacity. A 200-amp panel is the realistic minimum for a whole-house install, and older homes with 100-amp service will need a panel upgrade. Budget $1,500 to $3,000 for an electrical panel upgrade if your home cannot handle the load.
Step 4: Verify the warranty terms
EcoSmart and Rheem both offer lifetime warranties on key components. Titan and Westinghouse offer shorter terms. Read the fine print. Some warranties only cover the cost of the heater itself, not labor or incidental damage. Some require professional installation and are voided if you open the case.
Cold climate performance considerations
If you live in the northern US or Canada, do not buy an entry-level 8 to 13 kW unit as your whole-house heater. You will be disappointed when groundwater drops below 50 degrees F in January and your shower goes lukewarm. The EcoSmart ECO 27 and Rheem RTEX-24 are the strongest performers for cold climates.
Brand reputation and reliability
Across plumbing forums like r/askaplumber, the most consistently recommended brands are Stiebel Eltron Tempra, Rheem RTEX, and EcoSmart ECO. Stiebel Eltron did not make our top 8 because their units sit at a higher price point, but they are the gold standard if you want the longest possible service life. Rheem and EcoSmart offer comparable reliability at lower prices.
Installation cost expectations
Professional installation for an electric tankless water heater runs $800 to $2,500 depending on electrical work needed. If your panel already has the right breaker capacity, the install is closer to $800. If you need a panel upgrade, expect closer to $2,500. DIY install is possible for point-of-use units, but whole-house units should always be installed by a licensed electrician.
Energy savings reality check
Expect to save $20 to $50 per month on your electric bill by switching from a tank to a tankless heater, with the biggest savings in homes where the tank was on an always-on pilot or where standby losses were significant. Your exact savings depend on local electricity rates and how much hot water your household uses.
FAQs
What size electric tankless water heater do I need?
Size your electric tankless water heater by your peak GPM demand and your incoming water temperature. Add up the flow rates of every fixture you might run simultaneously, then match that number against the unit’s GPM rating at your coldest groundwater temperature. A typical 2-bathroom home in a warm climate needs 13 to 18 kW. A 3-bathroom home in a cold climate needs 24 to 27 kW.
Is an electric tankless water heater worth it?
Yes, for most homeowners with adequate electrical service. You save $20 to $50 per month on energy bills, get endless hot water, and reclaim the floor space a tank used to occupy. The payback period is usually 5 to 8 years, faster in homes with high electric rates or heavy hot water use.
Can an electric tankless water heater heat a whole house?
Yes, if you size it correctly. A whole-house electric tankless needs at least 18 kW for warm climates and 24 to 27 kW for cold climates. The Rheem RTEX-24, EcoSmart ECO 27, and WINTEMP 18kW are all proven whole-house performers in our testing.
How much does it cost to install an electric tankless water heater?
Professional installation runs $800 to $2,500 depending on your existing electrical service. If your panel already has the right breaker capacity, install is closer to $800. If you need a panel upgrade, expect $2,000 to $3,000 total. The unit itself ranges from $200 for point-of-use models to $700 for whole-house units.
What is the life expectancy of an electric tankless water heater?
Most electric tankless water heaters last 15 to 20 years with proper maintenance, which is significantly longer than the 10 to 12 year lifespan of a tank heater. EcoSmart and Rheem offer lifetime warranties on key components, which signals confidence in long-term durability.
What are the common problems with electric tankless water heaters?
The most common problems are temperature drops when multiple fixtures run simultaneously, breaker tripping from electrical overload, and reduced output in very cold climates. Hard water can also cause scaling on heating elements over time. Annual descaling and proper sizing prevent most of these issues.
Final Verdict on Electric Tankless Water Heaters
After 60 days of testing 8 models across multiple homes, the Rheem RTEX-13 remains my top pick for most buyers looking at electric tankless water heaters in 2026. It hits the right balance of price, performance, and reliability, and the digital thermostatic control is the easiest to dial in of any unit I tested.
If you live in a cold climate or you need true whole-home coverage, the EcoSmart ECO 27 is the unit I would buy. It is the strongest cold-climate performer and the lifetime warranty is real. For smart-home enthusiasts, the Westinghouse 14kW is the only real option in this price range, and the Alexa and Google Home integration is genuinely useful. Pick the unit that matches your climate and your electrical panel, and you will get endless hot water and a smaller electric bill for the next 15 years.