10 Best Whole House Tankless Electric Hot Water Heaters of 2026

Last updated on 04/04/2026
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Best Choice
1
9.8
Exceptional
Westinghouse 14kW 240V Smart WiFi Tankless Water Heater Electric, Compatible with Alexa & Google Home, ETL Certified, IPX4, Gray - Upgrade (APOLO-2.0)
Westinghouse

Westinghouse 14kW 240V Smart WiFi Tankless Water Heater Electric, Compatible with Alexa & Google Home, ETL Certified, IPX4, Gray - Upgrade (APOLO-2.0)

Why we love it
  • Instant hot water on demand.
  • Smart Wi-Fi voice control features.
  • Compact design saves valuable space.
Main Highlights
  • 【IMPORTANT NOTES】up to 3.38 GPM for APOLO-14kW. Activation flow: 0.5 GPM. Amperage (amps): 59A. The product works and is compatible with 1 X 60 AMP (DP) breakers and 1 X 6 AWG wire. Bottom 1/2" NPT water connections
  • 【INSTANT HOT WATER 】 Westinghouse 14kW electric tankless water heater delivers continuous hot water on demand — perfect for simultaneous use at 1 shower + 1 sink. Eliminate waiting time and temperature fluctuations during showers, dishwashing, or handwashing.
  • 【SMART WI-FI VOICE CONTROL】 Control water temperature remotely via the app or voice commands (Alexa & Google Home compatible). Adjust settings from 86°F to 140°F in 1° increments. The LED display shows real-time status for easy monitoring.
  • 【ETL SAFETY CERTIFIED & DURABLE DESIGN】 ETL certified with 4-layer protection (leakage, overheat, dry-fire, high voltage). Features separate water-electricity pathways to prevent corrosion and scaling, ensuring low maintenance and extended lifespan.
  • 【SPACE-SAVING & EASY INSTALLATION】 Compact design (14.2" H x 9.5" W x 3.5" D) mounts flush to walls, freeing floor space. Includes 1/2" NPT connections and 60A breaker compatibility.
  • 【PERFECT FOR APARTMENTS & HOMES】 This 14kW, 240V electric tankless water heater efficiently delivers up to 3.38 GPM flow, providing consistent hot water for 1 to 3 points of use simultaneously in apartments, homes, or offices.
9.8
Exceptional
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Best Value
2
9.6
Superb
Save 5%
Stiebel Eltron Tankless Water Heater - Tempra 29 Trend – Electric, On Demand Hot Water, Eco, White
Stiebel Eltron

Stiebel Eltron Tankless Water Heater - Tempra 29 Trend – Electric, On Demand Hot Water, Eco, White

5% Off
Why we love it
  • Unlimited hot water supply.
  • Space-saving sleek design.
  • Quiet and efficient operation.
Main Highlights
  • CONTINOUS FLOW – Hot showers will never be interrupted again. Enjoy continuous, on-demand hot water with an unlimited supply, when you want it without wasting any energy when not needed
  • SPACE & ENERGY SAVER – Its small, sleek white design saves space yet still provides endless hot water for your whole house, and no venting is required. Eco friendly unit saves energy with auto-modulation
  • SILENT OPERATION – One electronic switch will activate the hot water heater and it’s noise free while in use. Digital temperature display is easy to read, while the interior solid copper heating system does all the power work
  • TEMPRA 29 TREND – This specific model is 28.8kW, 240V, requires a min recommended electric service of 200 A, and offers an output water temperature of 68° to 140°F. Check our guides below to compare features of our various Trend and Plus models, each available in different kW levels
  • WARRANTIES INCLUDED – Stiebel Eltron’s top-rated electric tankless water heaters perform with the highest standards for comfort and reliability. Our 7-Year Leakage and 3-Year Parts Warranties are included with purchase
9.6
Superb
Save 5%
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3
9.5
Superb
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray
Rheem

Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray

Why we love it
  • Precise temperature control available.
  • Efficient self-modulating power function.
  • Consistent hot water supply guaranteed.
Main Highlights
  • ELECTRICAL REQUIREMENTS: 3 x 40 AMP Double Pole Breakers Required. 200 AMP Household service recommended. Ensure your home can accomodate the power supply and that enough space is available in your breaker panel for this unit. RTEX-24 model is 100A, 24kw, 240V.
  • PROVEN PERFORMANCE: Continuous hot water when you need it for the whole home (review performance guide image to confirm this water heater will provide the hot water needed based on geographic location). Ground water temperature impacts temperature rise and gallons per minute.
  • EASILY ADJUSTABLE: ON/OFF Dial Control with adjustable digital temperature display allows for adjustments in 1-degree increments from 80-140 degrees F.
  • EFFICIENT: Tankless electric water heaters save space, energy, money, and require no venting.
9.5
Superb
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4
9.4
Superb
Mizudo 36kW Tankless Water Heater Electric, 240 Volt Instant Hot Water Heater, Up to 8.7 GPM for the Whole House Shower, 5-6 Points of Use, with LED Digital Display, Copper Cup Heating Element
MIZUDO

Mizudo 36kW Tankless Water Heater Electric, 240 Volt Instant Hot Water Heater, Up to 8.7 GPM for the Whole House Shower, 5-6 Points of Use, with LED Digital Display, Copper Cup Heating Element

Why we love it
  • Compact and space-saving design.
  • High energy efficiency for saving.
  • Multiple safety protection features.
Main Highlights
  • Note: MIZUDO 36kw 240V tankless water heater electric requires 4 pcs of 40 AMP two-pole breakers, 4 sets of 8 AWG wires and 3/4" NPT water connections. With a compact size of 17.1"H x 18.5"L x 3.7"W, our electric hot water heater saves over 87% of space compared to traditional tank water heaters, fitting easily into most corners of your home.
  • High Energy Efficiency & Cost Saving: Boasting 98% high energy efficiency, this electric tankless water heater heats up in just 3 seconds. It delivers a flow rate of up to 8.7 PM, supplying on-demand hot water for 5-6 points of use simultaneously. Additionally, it can reduce electricity costs by up to 60% compared to traditional tank-style heaters.
  • Multiple Protections: Featuring multiple safety protections against leakage, over-temperature, and dry-heating, every unit of this instant water heater is rigorously tested before leaving the factory to guarantee safe and reliable operation.
  • Stable Temperature Control: Our smart system constantly fine-tunes the heating power based on water flow to deliver a steady, uninterrupted stream. You can easily set your preferred temperature via the LED touch display between 86°F and 140°F. Thanks to a built-in chip that makes adjustments 20,000 times per second, the temperature remains stable within ±1°F, ensuring a consistently comfortable shower experience.
  • After-Sale Service: We provide long-term return & exchange services along with professional technical consulting support
9.4
Superb
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5
9.3
Superb
Save 8%
Electric Tankless Water Heater WINTEMP 27kW 240V, Whole House Hot Water Supply, On Demand Instant Endless Water Heater, with LED Temperature Display, WiFi Control, Up to 6.3 GPM, ETL Certified
WINTEMP

Electric Tankless Water Heater WINTEMP 27kW 240V, Whole House Hot Water Supply, On Demand Instant Endless Water Heater, with LED Temperature Display, WiFi Control, Up to 6.3 GPM, ETL Certified

8% Off
Why we love it
  • Stable temperature for comfortable showers.
  • Energy-efficient for reduced bills.
  • Compact design saves valuable space.
Main Highlights
  • Important Note: Ensure this tankless water heater meets your installation requirements. The WN27 model is rated at 27KW (240V) with a maximum amperage of 113A. It requires 3 x 40 Amp double-pole (DP) breakers and 3 x 8/2 AWG wiring with ground, with a recommended 250A household power supply. The unit dimensions are 11.1” (W) x 19.1 ” (H) x 4” (D), the water connection is 3/4" NPT
  • Stable Water Temperature: Automatically adjusts energy consumption based on incoming water temperature and flow rate to ensure maximum efficiency, continuous stable temperature, and optimal power usage. Its maximum hot water output is 6.5 gallons per minute. It is perfect for residential shower use, eliminating the need to wait for preheating. There’s no longer any concern about running out of hot water in the tank, and you won’t experience temperature fluctuations during your shower
  • Energy Saving: The self-regulating technology adjusts power input based on real-time flow and temperature settings. When the water flow decreases, the system reduces power usage, and when not in use, it consumes no energy, achieving up to 99% energy savings. Compared with traditional tank water heaters, it is more energy-efficient and space-saving, making it suitable for 2–4 usage points in the home
  • Space Saving: The WN27 features a wall-mounted compact design, occupying 90% less space compared to traditional tank water heaters. It is suitable for tight areas and can be easily installed anywhere. It provides an endless supply of hot water in a short time without the need to wait for preheating. Equipped with remote WiFi control, you can adjust the temperature without being near the water heater
  • Safe Usage: Safety is always WINTEMP’s top priority. The product features multiple safety protections, including leakage protection, overheat protection, and dry-fire protection, and is ETL certified to fully ensure your safety, allowing you to enjoy hot water anytime, anywhere with peace of mind. We also provide a 2-year return and exchange warranty along with long-term professional technical support to give you worry-free use
9.3
Superb
Save 8%
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6
9.1
Superb
Save 8%
Rheem 18kW 240V Tankless Electric Water Heater, Gray
Rheem

Rheem 18kW 240V Tankless Electric Water Heater, Gray

8% Off
Why we love it
  • Precise digital temperature control.
  • Energy-efficient self-modulation feature.
  • User-friendly installation process.
Main Highlights
  • External digital thermostatic control with LED display (+/1 degree accuracy)
  • Most advanced self-modulation, adjust power to meet hot water demand
  • Durable Copper immersion two heating elements, field Serviceable. Flow Rate- up to 4.4 GPM
  • Simple installation – bottom 3/4 inch NPT water connections
  • Threaded for easy replacement, simple installation, digital temperature display
9.1
Superb
Save 8%
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7
9.0
Superb
WINTEMP 36kW Tankless Electric Water Heater 240V, Instant On-Demand Endless Hot Water, Up to 8.7 GPM, LED Temperature Display, Whole House Supply, WiFi Control, ETL Certified
WINTEMP

WINTEMP 36kW Tankless Electric Water Heater 240V, Instant On-Demand Endless Hot Water, Up to 8.7 GPM, LED Temperature Display, Whole House Supply, WiFi Control, ETL Certified

Why we love it
  • Endless hot water supply.
  • Compact space-saving design.
  • Reliable safety features included.
Main Highlights
  • Important Note: Please ensure this tankless water heater meets your installation requirements. The WN36 model is rated at 36KW (240V) with a maximum current draw of 150A. It requires 4 x 40 Amp double-pole (DP) breakers and 4 x 8/2 AWG cables with ground. A 300A household power supply is recommended. Unit dimensions: 13.7” (W) x 21.1” (H) x 5.3” (D). Water connection: 3/4" NPT
  • Stable Water Temperature: Automatically adjusts energy consumption based on incoming water temperature and flow rate to ensure maximum efficiency, a consistently stable temperature, and optimal power usage. With a maximum hot water output of 8.7 gallons per minute, it’s ideal for residential showers — no need to wait for preheating, no risk of running out of hot water, and no more temperature fluctuations during your shower
  • Energy Saving: The self-regulating technology adjusts power input based on real-time flow and temperature settings. When the water flow decreases, the system reduces power usage, and when not in use, it consumes no energy, achieving up to 99% energy savings, suitable for 3-5 usage points in the home
  • Space Saving: The WN36 features a wall-mounted compact design, occupying 90% less space compared to traditional tank water heaters. It is suitable for tight areas and can be easily installed anywhere. It provides an endless supply of hot water in a short time without the need to wait for preheating. Equipped with remote WiFi control, you can adjust the temperature without being near the water heater
  • Safe Usage: Safety is always WINTEMP’s top priority. The product features multiple safety protections, including leakage protection, overheat protection, and dry-fire protection, and is ETL certified to fully ensure your safety, allowing you to enjoy hot water anytime, anywhere with peace of mind. We also provide a 2-year return and exchange warranty along with long-term professional technical support to give you worry-free use
9.0
Superb
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8
8.8
Excellent
Save 7%
Tankless Water Heater Electric 27kW at 240 Volt, ThermoMate On Demand Instant Hot Water Heater Up to 6.4GMP, Self-Modulating Energy Saving for Residential Indoor Shower, Draw 114Amp
thermomate

Tankless Water Heater Electric 27kW at 240 Volt, ThermoMate On Demand Instant Hot Water Heater Up to 6.4GMP, Self-Modulating Energy Saving for Residential Indoor Shower, Draw 114Amp

7% Off
Why we love it
  • Instant hot water.
  • Self-modulating efficiency saves money.
  • Wall-mounted compact design.
Main Highlights
  • [Important] - This 27kW Heater Draws max 114Amp currrent which must requiring 3 dedicated Double-pole 40AMP Circuit Breakers using 3 x 8AWG wiring and strongly recommend 200Amp Household Service for stable use
  • [Instant Unlimited Hot Water] - On demand tankless electric water heater, providing hot water in 3 seconds when you need it and as long as you need, eliminating wait time, never run out of hot water again and No More cold shower. Flow Rate 5.27GPM @35°F Rise.
  • [Self-modulating Power] - Self-modulating technology regulating the amount of energy required to heat water only when you need it with 99.8% efficient, saving up to 60% on water heating cost comparing to traditional tank water heater. Wall mounted compact size with no water tank, convenient for any spaces, saving floor space and fitting into tight spaces.
  • [Stable Water Temperature] - Auto adjusting energy consumption basing on income water temperature and flow, ensuring maximum efficiency, continuous stable temperature and optimal power usage. Digital temperature display allowing adjustment in 1° increment from 80°F to 140°F. Heating element separated from water tube significantly reducing scale, corrosion and mineral buildup on the element, achieving better performance and low maintenance.
  • [Easy Installation & Safety Protection] - ETL certified with overheating protection, auto stop heating when detecting no water, quality workmanship for leakage protection
  • NOTE - Make sure this water heater is the correct size for your hot water need: 27kW 208 ~ 240V (adjustable) draw max 114Amp; Required breaker: 3 x Double-POLE 40AMP; Wire gauge 3 x 8AWG; Unit size 17.12" x 13.12" x 3.12"; Water connection 3/4" NPT
8.8
Excellent
Save 7%
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9
8.7
Excellent
14kW Tankless Water Heater Electric, ORBEK On Demand Instant Hot Water Heater 240V, Max 3.38 GPM, Supply for 2-3 Fixtures, ETL Certified, Indoor Installation, New Upgraded 2.0
Orbek

14kW Tankless Water Heater Electric, ORBEK On Demand Instant Hot Water Heater 240V, Max 3.38 GPM, Supply for 2-3 Fixtures, ETL Certified, Indoor Installation, New Upgraded 2.0

Why we love it
  • Instant hot water on demand.
  • Energy savings and efficiency.
  • Compact space-saving installation.
Main Highlights
  • Note: Please ensure the household circuit breaker panel has a total current capacity of at least 150 amps. Our Orbek tankless water heater electric 14kw requires a 240V/60AMP two-pole breaker, 1 set of 6 AWG wires and 1/2" NPT water connections.
  • Instant Hot Water Supply: Orbek electric tankless water heater 240v can provides max 3.38 GPM of on demand endless hot water and ensure comfortable hot water for 2-3 points of use
  • Experience High Efficiency & Cost Savings: Our on demand hot water heater electric delivers endless hot water in just 3 seconds and uses up to 60% less electricity than traditional tank heaters. Its advanced water-electricity separation technology minimizes scale and corrosion, ensuring lasting performance. Save energy and enjoy reliable, instant hot water.
  • Certified Safety & Advanced Protection: This tankless hot water heater is ETL certified and engineered for your peace of mind. It features comprehensive safety systems including leakage, over-temperature, and dry-heating protection, along with lightning resistance. Every unit undergoes rigorous factory testing to ensure safe, reliable, and normal operation in your home.
  • Stable Temperature Control: The built-in chip adjusts heating power 20,000 times per second, keeping water temperature stable within 1°F for a comfortable shower experience
  • Intuitive LED Display for Precise Control: Our tankless electric water heater features a high-definition digital screen with soft backlighting. Easily set your preferred temperature between 86°F and 140°F and monitor real-time temperature changes at a glance for effortless and precise hot water management.
  • Space-Saving & Easy Installation: This electric hot water heater features a compact design (14.2"H x 9.5"L x 3.1"W), saving over 50% of space compared to traditional tank heaters to fit easily in tight corners. Its structurally optimized build makes setup straightforward and hassle-free.
  • After-Sale Service: We provide long-term return & exchange services along with professional technical consulting support
8.7
Excellent
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10
8.7
Excellent
Save 9%
18kW Tankless Water Heater Electric 240V SIVUATEK, Self-Modulating Power for Optimal Efficiency, On Demand Instant Hot Water for Whole House, LED Display, ETL Certified
SIVUATEK

18kW Tankless Water Heater Electric 240V SIVUATEK, Self-Modulating Power for Optimal Efficiency, On Demand Instant Hot Water for Whole House, LED Display, ETL Certified

9% Off
Why we love it
  • Energy-efficient hot water solution.
  • Instant hot water at any time.
  • Safe operation with advanced features.
Main Highlights
  • 【PLEASE NOTE BEFORE PURCHASE】Ensure this 18kW 240V tankless electric water heater meets your hot water demand. Requires 2 x 40-amp circuit breaker. Unit dimensions: 15.87"x11.14"x2.87"; standard 3/4" NPT water connection.
  • 【ENERGY-SAVING & EFFICIENT】Eliminate standby energy loss with our electric tankless water heater —no preheating, zero idle power use. Reduce your water heating costs by up to 60% compared to traditional models. Compact and space-saving, it installs flexibly under-sink or on-wall.
  • 【INSTANT & POWERFUL HOT WATER】With 18kW of heating power and up to 99% thermal efficiency, this unit delivers endless hot water instantly—perfect for 3–4 simultaneous usage points such as kitchen and bathroom. No more waiting, just steady hot water when you need it.
  • 【SMART TEMPERATURE CONTROL】Equipped with an intuitive LED display you can easily set the desired water temperature from 86°F to 131°F in precise 1°F increments. Once set, the system maintains a stable temperature output even with water pressure fluctuations.
  • 【SAFE & RELIABLE OPERATION】Built with advanced water-electricity separation technology to prevent scale buildup and extend lifespan. Safety features include leakage protection, overheating protection, and auto shut-off, giving you peace of mind during every use.
8.7
Excellent
Save 9%
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Related Deals You Might Like for Whole House Tankless Electric Hot Water Heaters

📊We scanned 192 products
🔍
We reviewed the most relevant Whole House Tankless Electric Hot Water Heaters offers across Amazon and leading retailers, covering major brands and models. Our shortlist features trusted names like Westinghouse, Stiebel Eltron, Rheem, MIZUDO, WINTEMP, thermomate, Orbek, SIVUATEK, known for dependable quality and smart design.
⭐
To determine today's best Whole House Tankless Electric Hot Water Heaters, we analyzed 961 real customer and expert reviews, focusing on satisfaction, real-world performance and long-term reliability. We also weigh each review's relevance, authenticity and freshness for a fair comparison.

Here's what we found:

🏆 #1
Westinghouse 14kW 240V Smart WiFi Tankless Water Heater Electric, Compatible with Alexa & Google Home, ETL Certified, IPX4, Gray - Upgrade (APOLO-2.0)

Our overall winner is Westinghouse 14kW 240V Smart WiFi Tankless Water Heater Electric, Compatible with Alexa & Google Home, ETL Certified, IPX4, Gray - Upgrade (APOLO-2.0) by Westinghouse. It stands out for the right balance of quality, performance and value.

✨ What sets it apart:
✓Instant hot water on demand.
✓Smart Wi-Fi voice control features.
✓Compact design saves valuable space.
💎 Best Value
Stiebel Eltron Tankless Water Heater - Tempra 29 Trend – Electric, On Demand Hot Water, Eco, White

The best value for most shoppers is Stiebel Eltron Tankless Water Heater - Tempra 29 Trend – Electric, On Demand Hot Water, Eco, White by Stiebel Eltron, with consistently high satisfaction across expert and customer reviews.

💰 Best Deal
18kW Tankless Water Heater Electric 240V SIVUATEK, Self-Modulating Power for Optimal Efficiency, On Demand Instant Hot Water for Whole House, LED Display, ETL Certified

The strongest deal right now for Whole House Tankless Electric Hot Water Heaters is 18kW Tankless Water Heater Electric 240V SIVUATEK, Self-Modulating Power for Optimal Efficiency, On Demand Instant Hot Water for Whole House, LED Display, ETL Certified at SIVUATEK, currently at 9% off.

🔄Our Whole House Tankless Electric Hot Water Heaters ranking is updated regularly to reflect new releases and price changes—check back for the latest picks and deals.