10 Best Tankless Water Heaters in 2026

Tankless water heaters provide endless hot water on demand without the need for a bulky storage tank. These modern units heat water instantly as it flows through the device, offering significant energy savings and space efficiency for homeowners looking to upgrade their plumbing systems.

We compared ten top-rated models from leading brands like Rheem, Westinghouse, and ThermoMate based on performance, efficiency, and safety features. Our analysis covers both electric and gas options to help you find the perfect match for your specific household needs and installation requirements.

Each pick in this guide highlights key strengths and ideal use cases so you can make an informed decision. Please note that availability and specifications may change over time, so always verify the latest details before making your final purchase decision for your home.

Top 3 Picks for Best Tankless Water Heaters

Top 10 Best Tankless Water Heaters in 2026 Compared

This side-by-side comparison highlights the key specifications and capabilities of each model to help you quickly identify which unit fits your home heating needs.

1. Westinghouse 11kW Tankless Water Heater Electric – Best Smart Electric Model

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Westinghouse 11kW Tankless Water Heater Electric

11kW Electric Power

WiFi Voice Control

240V Requirement

98% Efficiency

The Westinghouse 11kW Tankless Water Heater stands out as the top choice for modern smart homes seeking efficiency and convenience. With a perfect 5.0 rating from users, this electric unit delivers instant hot water in just three seconds while integrating seamlessly with your existing smart home ecosystem via voice control.

Pros

• Smart app integration
• Instant hot water
• High safety ratings
• Energy efficient
• Compact wall mount

Cons

• Requires 60A breaker
• Professional install advised

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Its standout features include WiFi compatibility allowing you to adjust temperatures remotely and voice command support for Alexa and Google Home. The temperature memory function ensures your preferred settings are restored after power outages, while the 4-layer protection system including leakage and overheat detection guarantees safe operation.

While it offers exceptional performance, users should note the electrical requirements of a dedicated 60A double-pole breaker and 8 AWG wire at 240V. This makes installation more involved than standard appliances but ensures stable and safe operation. The unit also requires cleaning the inlet filter every six months to maintain optimal flow.

This model is ideal for homeowners looking to upgrade to a smart home experience with reliable hot water for showers and sinks. The combination of high thermal efficiency, durable construction, and advanced connectivity features makes it a standout choice for residential applications today.

Smart Home Integration

Control your water temperature via mobile app or voice commands for ultimate convenience and energy management.

Safety and Durability

Built-in protections like IPX4 rating and separated water pathways ensure long-lasting safe operation in humid environments.

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2. Rheem RTGH Series 8.4 GPM Natural Gas – Best High Capacity Gas Model

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Rheem RTGH Series 8.4 GPM Natural Gas

8.4 GPM Flow

157,000 BTUs

Condensing Type

Indoor Install

The Rheem RTGH Series is a premium choice for large households needing robust hot water capacity. With an impressive 8.4 GPM flow rate at a 35-degree temperature rise, it can handle three to four simultaneous showers without any drop in temperature or pressure.

Pros

• High flow rate
• Ultra-low emissions
• Long warranty
• Energy efficient
• Safety features

Cons

• Requires professional install
• Higher upfront cost

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This model features industry-leading condensing technology that boosts its Uniform Energy Factor to 0.93, resulting in ultra-low gas bills. The ultra-low NOx emissions ensure compliance with strict environmental standards, making it a responsible choice for eco-conscious consumers.

Installation requires professional expertise due to direct venting and gas line requirements. However, the investment is supported by a 15-year heat exchanger warranty and a five-year parts warranty, ensuring long-term reliability and protection for your home heating system.

Best for large families or multi-bathroom homes, this unit delivers consistent performance with advanced safety features like built-in freeze protection. It is the perfect upgrade for those transitioning from a traditional tank system to a more efficient continuous hot water supply.

High Capacity Performance

Handles multiple water fixtures simultaneously without temperature drops for comfortable showers across the home.

Eco-Friendly Efficiency

Condensing technology reduces fuel consumption and emissions while maintaining high hot water output.

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3. ThermoMate 4.5kW Tankless Under Sink – Best Compact Budget Pick

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ThermoMate 4.5kW Tankless Under Sink

4.5kW Electric

Under Sink Use

120V Power

Compact Size

The ThermoMate 4.5kW Tankless Under Sink Water Heater is an excellent budget-friendly option for point-of-use heating needs. Designed to fit under sinks or in tight spaces, it provides instant hot water for faucets in bathrooms or kitchens without the bulk of a tank system.

Pros

• Affordable price
• Easy installation
• Touch control
• Space saving
• Waterproof rating

Cons

• Limited flow rate
• Single point use

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Its sleek compact size makes it ideal for small apartments or office restrooms where space is at a premium. The unit features a digital touch control panel allowing precise temperature adjustments in one-degree increments ensuring consistent hot water delivery every time.

While it is not designed for whole-house heating, it excels at specific tasks like hand washing or dish washing. The self-modulating power feature ensures energy efficiency by only using what is needed to heat water when the faucet is on.

This model is perfect for renters or homeowners looking for a simple cost-effective upgrade to a specific faucet. The IP25 waterproof rating and ETL approval provide peace of mind regarding safety and durability in daily residential use.

Space Efficient Design

Compact dimensions allow installation in tight cabinets or under counters where larger units would not fit.

Instant Point of Use

Delivers hot water in seconds to faucets saving energy and eliminating cold water wait times.

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4. Rheem RTG Series 7.0 GPM Natural Gas – Best Standard Gas Model

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Rheem RTG Series 7.0 GPM Natural Gas

7.0 GPM Flow

160,000 BTUs

Natural Gas

Indoor Install

The Rheem RTG Series offers reliable whole-house heating for residential use with a strong flow rate of 7.0 GPM. It delivers endless instant hot water for two to three simultaneous showers ensuring that your household never runs out of hot water during peak usage times.

Pros

• High efficiency
• LeakGuard included
• Digital controls
• Space saving
• CSA certified

Cons

• Venting required
• Installation costs

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This model is equipped with LeakGuard Leak Detection and Prevention technology which protects your home from water damage by detecting internal leaks. Combined with advanced safety features like freeze protection and flame failure protection, it offers robust security for your home infrastructure.

Energy efficiency is a key selling point with a Uniform Energy Factor of 0.82 that can save up to 34 percent on energy costs compared to tank heaters. The digital LED temperature control panel allows for precise adjustments ensuring comfortable water temperatures at all times.

Ideal for replacing aging tank water heaters, this unit frees up valuable floor space with its wall-mount design. It is a solid choice for families looking for a balance of performance safety and energy savings without the complexity of condensing systems.

Leak Protection

Built-in LeakGuard monitors the system for leaks preventing potential water damage and costly repairs.

Efficiency Savings

On-demand heating technology significantly reduces energy bills compared to maintaining a heated tank.

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5. 14kW ORBEK Tankless – Best Mid-Range Electric

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14kW ORBEK Tankless

14kW Electric

3.38 GPM

240V Power

LED Display

The 14kW ORBEK Tankless Water Heater delivers comfortable hot water for multiple points of use with a solid flow rate. Its advanced water-electricity separation technology minimizes scale buildup ensuring lasting performance and reducing the need for maintenance over time.

Pros

• Energy efficient
• Stable temp control
• Compact design
• Safety protections
• Easy install

Cons

• Requires 60A breaker
• Limited to 3 points

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Users appreciate the stable temperature control provided by the built-in chip which adjusts power 20,000 times per second. This ensures that water temperature stays within one degree of the set point for a comfortable shower experience even when water pressure fluctuates.

Safety is prioritized with ETL certification and multiple protection systems including leakage over-temperature and dry-heating protection. The unit also features lightning resistance and undergoes rigorous factory testing to ensure safe operation in various residential environments.

This model is well-suited for households looking for an affordable electric solution with reliable performance. The compact design saves space while providing enough capacity for a shower and kitchen use making it a versatile upgrade for many homes.

Stable Temperature

High-speed chips adjust heating power instantly to maintain consistent water temperature.

Durability

Separation technology protects internal components from corrosion extending the unit's lifespan.

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6. 14kW Tankless Electric – Best Value 14kW

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14kW Tankless Electric

14kW Electric

Sink & Shower

240V Power

LED Display

The 14kW Tankless Electric Heater offers an efficient solution for simultaneous usage in kitchens and bathrooms. With thermal efficiency up to 99.8 percent it eliminates standby energy loss ensuring you only pay for the hot water you actually use.

Pros

• Energy saving
• Instant heating
• Temperature memory
• Safe operation
• Compact size

Cons

• Requires 60A breaker
• Wiring complexity

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Its intuitive LED display allows for precise temperature settings and adjustments from 86 to 131 degrees Fahrenheit. The system maintains stable output even with water pressure changes ensuring a consistent and comfortable experience for users.

Safety features include leakage protection overheating protection and auto shut-off providing peace of mind. The advanced water-electricity separation technology helps prevent scale buildup extending the lifespan of the unit and reducing maintenance needs.

Best for small to medium homes needing a reliable electric backup or primary heater, this unit is designed for easy installation with straightforward wiring. The space-saving design makes it a great fit for tight spaces where traditional tanks cannot be installed.

High Efficiency

Zero idle power use means you save energy by not heating water until it is needed.

User Friendly Controls

Simple LED interface makes setting and monitoring temperatures easy for all users.

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7. 18L Propane Tankless – Best Portable Outdoor

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18L Propane Tankless

Propane Fuel

4.76 GPM

Portable Design

Indoor Outdoor

The 18L Propane Tankless Water Heater is the perfect companion for camping RV travel and outdoor activities. With a high heating output of 115,425 BTU per hour it delivers steady hot water for showers and washing in remote locations without power access.

Pros

• Portable and light
• High BTU output
• Safety features
• Digital display
• Easy setup

Cons

• Requires propane tank
• Not permanent install

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Its lightweight and compact design makes it easy to carry and set up anywhere. The digital display allows you to adjust the temperature between 17 and 113 degrees Fahrenheit ensuring comfort in various outdoor conditions.

Safety is critical for outdoor use and this unit includes comprehensive protections such as overheat protection dry combustion prevention and flame failure cutoff. These features ensure peace of mind during every trip regardless of the terrain or conditions.

Ideal for adventurers and pet owners who need hot water on the go this heater provides reliable performance without the bulk of a tank. It is an essential piece of gear for anyone looking to enhance their outdoor experience with comfort and convenience.

Outdoor Versatility

Designed for camping and RV use providing hot water wherever you need it without fixed plumbing.

Safety Protections

Multiple built-in safety systems prevent hazards during use in challenging environments.

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8. 110V 3000W Tankless – Best Standard 110V

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110V 3000W Tankless

3000W Power

110V Standard

Under Sink Use

LED Display

The 110V 3000W Tankless Water Heater is designed for standard outlets making it incredibly easy to install under sinks. With power up to 82 degrees at low flow it provides instant hot water for hand washing and dishwashing in apartments and small homes.

Pros

• Easy plug in
• Compact design
• Energy efficient
• Waterproof safety
• Simple install

Cons

• Low flow rate
• Not for showers

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Its compact wall-mounted design frees up valuable space while the advanced safety features ensure safe operation. The unit includes leakage protection dry boil protection and auto shut-off ensuring peace of mind during every use.

Note that this model is not suitable for showers as the flow rate is limited. It is ideal for point-of-use applications where a small reliable supply of hot water is needed without complex electrical upgrades.

Best for renters or those looking for a quick upgrade to a kitchen or bathroom sink this unit delivers reliability and energy savings. The ETL certification and 24-month warranty add to its value and user confidence.

Plug-and-Play

Standard 110V outlet compatibility allows for simple setup without needing an electrician.

Compact Utility

Small footprint fits easily under sinks keeping your countertops clear and organized.

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9. 110V 3000W Tankless – Best 110V Option

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110V 3000W Tankless

3000W Power

110V Standard

Under Sink Use

Energy Efficient

The 110V 3000W Tankless Water Heater is a highly rated option for standard electrical setups. It raises water temperature quickly at low flow rates making it perfect for small sinks in apartments or offices where a tank is not feasible.

Pros

• High rating
• Easy install
• Energy efficient
• Safety protected
• Compact size

Cons

• Flow rate limited
• Not for showers

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Safety is a priority with multiple safeguards including IPX4 waterproofing and dry-boil prevention. The unit is also ETL certified ensuring it meets rigorous safety standards for residential use.

Installation is straightforward with pre-drilled holes and standard connections. Users can easily mount it on a wall to save space while enjoying the benefits of on-demand hot water for daily tasks.

Ideal for those looking for a reliable affordable solution for point-of-use heating this model delivers consistent performance. The 24-month warranty and responsive customer support provide additional confidence for your purchase.

Reliable Performance

High thermal efficiency ensures warm water is available whenever needed without wasting energy.

Safety First

Multiple protections like dry-boil prevention ensure safe operation in compact spaces.

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10. 18kW Electric Tankless – Best High Output Electric

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18kW Electric Tankless

18kW Electric

Self-Modulating

WiFi Control

4.3 GPM

The 18kW Electric Tankless Water Heater delivers powerful performance suitable for multiple bathroom homes. Its self-modulating technology adjusts power consumption based on flow rate ensuring stable temperature and maximum efficiency during use.

Pros

• High flow rate
• Energy savings
• WiFi remote
• Compact design
• ETL certified

Cons

• Requires 150A service
• Heavy electrical demand

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With WiFi control you can adjust the temperature remotely and monitor usage easily. This feature adds convenience and allows for better management of your household's energy consumption.

Installation requires significant electrical capacity and consultation with a qualified electrician is recommended. However once installed it frees up storage space and provides endless hot water without the need for preheating.

Ideal for homeowners in mild climates needing high output electric heating this unit offers reliable comfort. The safety protections and 2-year warranty ensure peace of mind while you enjoy hot water anytime and anywhere.

Powerful Output

High flow rate ensures enough hot water for multiple showers or household uses simultaneously.

Smart Control

Remote WiFi access lets you manage settings conveniently from your smartphone.

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Buying Guide – How to Choose the Best Tankless Water Heaters

Selecting the right tankless water heater involves understanding your home's needs and the available options.

Fuel Type

Choose between electric gas or propane based on your home's existing utilities and availability. Electric units are easier to install but may require significant electrical upgrades while gas units provide higher flow rates for whole-house use.

Consider fuel costs and installation requirements when deciding which fuel type fits your home best.

Flow Rate

Flow rate measured in gallons per minute determines how much hot water the unit can deliver. Larger homes with multiple bathrooms should look for higher flow rates to ensure simultaneous showers and sinks do not run out of hot water.

Calculate your peak flow needs by adding up the flow rates of fixtures you use at the same time.

Power Requirements

Electric tankless heaters often require dedicated circuits with high amperage and specific wire gauges. Check your electrical panel to ensure it can handle the new load before purchasing an electric model.

Always consult a qualified electrician to confirm your home's capacity and ensure safe installation.

Energy Efficiency

Energy efficiency ratings help you understand how much energy the unit will consume compared to traditional tanks. Higher efficiency means lower utility bills and a smaller environmental footprint.

Look for models with self-modulating technology that adjust power use based on real-time demand.

Installation Space

Tankless units are compact but require specific clearances for ventilation and maintenance. Measure your available space carefully to ensure the unit fits without obstructing other systems.

Wall-mountable designs are common and help maximize floor space in utility rooms or closets.

Safety Features

Modern units come with essential safety features like overheat protection leakage detection and freeze protection. These features protect your home from potential damage and ensure safe operation.

Always choose models certified by recognized standards organizations for reliability and compliance.

Smart Controls

Smart features like WiFi and voice control allow you to adjust temperatures remotely. These conveniences can enhance your experience and help manage energy usage more effectively.

Consider if smart integration is a priority for your lifestyle when comparing different models.

Warranty

Warranties vary by manufacturer and model typically covering parts and heat exchangers for different periods. A longer warranty indicates confidence in product durability and longevity.

Review warranty terms carefully and ensure you understand any requirements for maintaining coverage.

How to Use and Care for Your Tankless Water Heaters

Regularly check inlet filters and clean them to maintain optimal water flow and heating performance. Sediment buildup can reduce efficiency and shorten the lifespan of the unit.

Set the temperature to a comfortable level that balances safety and energy savings. Most users find settings around 120 degrees Fahrenheit ideal for daily use.

Schedule periodic maintenance checks with a professional to inspect connections and safety features. This helps ensure the unit continues to operate safely and efficiently over time.

Frequently Asked Questions

Final Thoughts on Choosing the Best Tankless Water Heaters