Finding the best 120 volt tankless water heater can be a game-changer for your home. These compact, on-demand units provide instant hot water right where you need it, perfect for a sink, bathroom, or small apartment. They save space and energy compared to traditional tanks. In this guide, we’ve tested and compared the top models to help you make the perfect choice for your needs.
In This Article
- 1 Quick Product Comparison
- 2 Our Top 10 Best 120 Volt Tankless Water Heater Reviews – Expert Tested & Recommended
- 2.1 1. Hydro Master Tankless Water Heater Service Valve Kit with Pressure Relief Valve for 3/4-Inch IPS Connections
- 2.2 2. Under Sink Tankless Water Heater, Electric, 110V/120V, Point of Use, Instant Hot Water, Compact Design
- 2.3 3. SIVUATEK 14kW 240V Electric Tankless Water Heater for Whole House Use with Self-Modulating and Compact Design
- 2.4 4. Stiebel Eltron Tempra 29 Plus Electric Tankless Water Heater with Eco Mode and On-Demand Hot Water
- 2.5 5. Rheem 3.5kW 120V Thermostatic Tankless Electric Water Heater for Point of Use
- 2.6 6. Mini Tankless Under Sink Instant Hot Water Heater Electric 3kW 120V Plug-in, Enlarged LED Digital Display
- 2.7 7. Bosch Tronic 3000 T 4-Gallon Electric Mini-Tank Water Heater with Shelf, Wall, or Floor Mount Options
- 2.8 8. Electric Tank Water Heater
- 2.9 9. Electric Tankless Water Heater for Under Sink Use in Kitchen and Bathroom: 110V 3000W with Digital Display
- 2.10 10. Tankless Water Heater Electric, Under Sink Instant Hot Water 110V 3KW, On Demand Point of Use for Kitchen and Bathroom
- 3 Complete Buying Guide for Best 120 Volt Tankless Water Heater
- 4 Frequently Asked Questions
- 4.1 Q: Can a 120 volt tankless water heater run a shower?
- 4.2 Q: How do I install a 120 volt tankless water heater?
- 4.3 Q: Are tankless water heaters more energy-efficient than tank models?
- 4.4 Q: What maintenance do 120 volt tankless water heaters need?
- 4.5 Q: How long do 120 volt tankless water heaters last?
Quick Product Comparison
Our Top 10 Best 120 Volt Tankless Water Heater Reviews – Expert Tested & Recommended
1. Hydro Master Tankless Water Heater Service Valve Kit with Pressure Relief Valve for 3/4-Inch IPS Connections
This Hydro Master valve kit is a must-have for installing or maintaining your tankless water heater. It includes everything you need for a secure connection, like hot and cold isolation valves and a pressure relief valve. Made from durable forged brass, it ensures a leak-free setup that lasts.
Key Features That Stand Out
- ✓ Durable forged lead-free brass construction
- ✓ All-in-one kit with isolation and pressure relief valves
- ✓ Full port ball valves for maximum flow
- ✓ Wide compatibility with brands like Rheem and Rinnai
- ✓ Factory-tested for reliability
Why We Recommend It
We love this kit because it simplifies installation and adds an extra layer of safety. The quality materials mean you won’t have to worry about leaks or repairs down the line.
Best For
This is best for DIY enthusiasts or professionals looking for a reliable valve kit to pair with their tankless water heater installation.
Pros and Cons
Pros:
- High-quality, durable brass build
- Comprehensive kit with essential valves
- Easy to install with standard connections
- Enhances safety with pressure relief
Cons:
- May be overkill for very simple setups
- Requires basic plumbing knowledge for installation
Customer Reviews
Customer Review: “I recently installed the Hydro Master Tankless Water Heater Valve Kit, and I’m thoroughly impressed. This kit made the installation incredibly easy and hassle-free. The valves are of excellent quality, providing a secure and leak-free connection.”
Customer Review: “I bought an electric tankless Stiebel Eltron Tempra 36pro and used this heavy duty, solid brass valve set. The valves fit perfectly straight out of the box. These are solid and well-made.”
2. Under Sink Tankless Water Heater, Electric, 110V/120V, Point of Use, Instant Hot Water, Compact Design
This under-sink tankless water heater is perfect for getting instant hot water in your kitchen or bathroom. It runs on standard 120V power and has a sleek, compact design that fits neatly under most sinks. With smart features like frequency conversion, it saves energy by adjusting power based on demand.
Key Features That Stand Out
- ✓ Compact and sleek design for under-sink installation
- ✓ Energy-saving frequency conversion technology
- ✓ Safety features with memory and alarm functions
- ✓ Easy to use with intuitive controls
- ✓ 120V plug-in for convenient setup
Why We Recommend It
We recommend this model because it delivers hot water on demand without taking up much space. The energy-efficient operation helps cut down on electricity bills.
Best For
Best for small homes, apartments, or anyone needing a point-of-use hot water solution for a single sink.
Pros and Cons
Pros:
- Instant hot water with no waiting
- Compact size ideal for tight spaces
- Energy-efficient with smart power adjustment
- Simple installation with plug-in design
Cons:
- May not handle high flow rates for showers
- Requires a dedicated circuit for optimal performance
Customer Reviews
Customer Review: “I’ve just unboxed this 6.5KW tankless water heater for our kitchen. First impressions are promising. Its compact design is perfect for our limited space. The promise of instant hot water is exciting.”
Customer Review: “Installation was straightforward, and it works well for our sink. The hot water comes quickly, and the energy savings are noticeable.”
3. SIVUATEK 14kW 240V Electric Tankless Water Heater for Whole House Use with Self-Modulating and Compact Design
Note: This is a 240V model, but we include it for comparison. The SIVUATEK heater offers whole-house hot water with a self-modulating feature that adjusts power based on flow. It’s compact and has a user-friendly digital display for easy temperature control.
Key Features That Stand Out
- ✓ Self-modulating technology for energy efficiency
- ✓ Compact design suitable for point-of-use or whole house
- ✓ Digital display for precise temperature control
- ✓ Provides endless hot water on demand
- ✓ Easy installation with included template
Why We Recommend It
We recommend it for its balance of performance and affordability. The smart modulation saves power while delivering consistent hot water.
Best For
Best for budget-conscious users needing a reliable whole-house or large-point-of-use solution with 240V power.
Pros and Cons
Pros:
- Affordable price for a 14kW model
- Self-modulating saves energy
- Compact and easy to install
- Digital controls for convenience
Cons:
- Requires 240V wiring, not 120V
- May need professional installation for some homes
Customer Reviews
Customer Review: “Update: if power goes out, it stays off. Mounting was a breeze with included template. My water is around 85 F, so no reduction in flow at the sink.”
Customer Review: “Bought this to replace an older one. It works better than the Marley we had for years!”
4. Stiebel Eltron Tempra 29 Plus Electric Tankless Water Heater with Eco Mode and On-Demand Hot Water
The Stiebel Eltron Tempra 29 Plus is a premium 240V tankless water heater known for its reliability and eco-friendly features. It provides a continuous supply of hot water with two temperature presets for convenience. Its sleek design saves space and requires no venting.
Key Features That Stand Out
- ✓ Eco mode for energy savings
- ✓ On-demand unlimited hot water
- ✓ Sleek, space-saving design with no venting needed
- ✓ Two temperature memory presets
- ✓ Hard-wired for 240V or 208V service
Why We Recommend It
We recommend it for its high performance and energy efficiency. The brand is trusted, and the Eco mode helps reduce power consumption without sacrificing comfort.
Best For
Best for homeowners wanting a reliable, whole-house tankless water heater with advanced features and 240V power.
Pros and Cons
Pros:
- Consistent and unlimited hot water
- Energy-efficient Eco mode
- Compact and ventless design
- User-friendly temperature presets
Cons:
- Requires professional installation due to high power needs
- Higher upfront cost
- Not 120V, so check your electrical setup
Customer Reviews
Customer Review: “For five years I’ve lived with a gas heater. I decided to go electric for solar compatibility. The installation went smoothly, and I’m happy with the results.”
Customer Review: “I recently had this installed in my two-story home. The installation took about four hours, and I couldn’t be happier. It provides great hot water on demand.”
5. Rheem 3.5kW 120V Thermostatic Tankless Electric Water Heater for Point of Use
This Rheem model is a true 120V tankless water heater designed for point-of-use applications. It’s compact, saving space under sinks or in small areas. With thermostatic controls, you can adjust the temperature in 1-degree increments for precise comfort.
Key Features That Stand Out
- ✓ 3.5kW power on 120V for easy installation
- ✓ Thermostatic temperature control from 80 to 140°F
- ✓ Compact size ideal for low-flow applications
- ✓ Saves space compared to traditional tanks
- ✓ Requires a 30-amp double pole breaker
Why We Recommend It
We recommend it because it’s from a reputable brand and offers reliable performance for single faucets or small spaces. The precise temperature control is a nice touch.
Best For
Best for bathrooms, office breakrooms, wet bars, or garages where you need hot water at one specific point.
Pros and Cons
Pros:
- True 120V operation for standard outlets
- Accurate thermostatic temperature control
- Compact and space-saving design
- Trusted Rheem brand quality
Cons:
- Limited to low-flow uses, not for showers
- Requires hard-wiring with a 30-amp breaker
Customer Reviews
Customer Review: “I’ve installed three of these, and all have worked flawlessly. One provides adequate hot water for a small home with a shower, sink, and appliances.”
Customer Review: “There are many factors to consider, like ground water temperature. I live in Florida, and this heater works well for my point-of-use needs.”
6. Mini Tankless Under Sink Instant Hot Water Heater Electric 3kW 120V Plug-in, Enlarged LED Digital Display
This mini tankless water heater is a 3kW 120V plug-in model perfect for under-sink installation. It has an enlarged LED digital display for easy control and is designed for low-flow use only, such as at a kitchen or bathroom sink.
Key Features That Stand Out
- ✓ 3kW 120V plug-in for simple setup
- ✓ Enlarged LED digital display with knob control
- ✓ Multi-protective and intelligent safety features
- ✓ Compact design for point-of-use
- ✓ Note: Not suitable for showers or multiple taps
Why We Recommend It
We recommend it for its user-friendly design and safety features. The plug-in option makes installation a breeze for DIYers.
Best For
Best for anyone needing a simple, under-sink hot water solution for a single faucet, with easy plug-and-play operation.
Pros and Cons
Pros:
- Easy plug-in installation
- Clear digital display for temperature control
- Multiple safety protections
- Affordable and compact
Cons:
- Limited to low-flow applications
- May not work well in very cold climates
Customer Reviews
Customer Review: “These are awesome, you should check your water heater every once a month. This brand is good so far!”
Customer Review: “This small 110 volt under counter tankless heater did not work for me. I had to send it back and get a tank style instead.”
7. Bosch Tronic 3000 T 4-Gallon Electric Mini-Tank Water Heater with Shelf, Wall, or Floor Mount Options
This Bosch mini-tank water heater is a 4-gallon electric model that provides hot water right where you need it. It’s not tankless but included for comparison. With flexible mount options and a 120V plug, it’s easy to install under sinks or in small spaces.
Key Features That Stand Out
- ✓ 4-gallon capacity for point-of-use hot water
- ✓ Flexible shelf, wall, or floor mount options
- ✓ Plugs into a 120V outlet for independent installation
- ✓ Glass-lined tank for long service life
- ✓ Thermal efficiency of 98%
Why We Recommend It
We recommend it for its reliability and ease of use. The small tank ensures hot water is always available without the wait of a tankless system.
Best For
Best for those who prefer a small storage tank over tankless, for applications like under-sink hot water in kitchens or bathrooms.
Pros and Cons
Pros:
- Consistent hot water with a small tank
- Easy plug-in installation
- Durable glass-lined construction
- Flexible mounting options
Cons:
- Takes up more space than tankless models
- Limited capacity for high-demand uses
Customer Reviews
Customer Review: “So far it’s working great. I mounted it under the kitchen sink. No more wasting water during a long wait. I get hot water in 6 seconds.”
Customer Review: “Bought this 5 years ago for my outdoor kitchen. It has worked well providing hot water when needed. Generally I don’t run out.”
8. Electric Tank Water Heater
This electric tank water heater is a mini-tank model that provides instant hot water with rapid reheat. It features a stainless steel tank for durability and multiple safety protections. It’s great for point-of-use applications where space is limited.
Key Features That Stand Out
- ✓ Rapid heating for instant hot water
- ✓ Durable stainless steel tank construction
- ✓ Safety features like leakage protection and auto temperature limit
- ✓ CE, ROHS, and FCC certified
- ✓ Compact design for easy installation
Why We Recommend It
We recommend it for its quick heating and robust safety features. The certifications ensure it meets high standards for reliability.
Best For
Best for small spaces like boats, RVs, or outdoor bars where you need a compact hot water solution with a tank.
Pros and Cons
Pros:
- Fast heating and reheat times
- High-quality stainless steel tank
- Comprehensive safety protections
- Compact and portable
Cons:
- Tank-based, so may run out of hot water
- Not tankless, so requires storage space
Customer Reviews
Customer Review: “We tried a small instant water heater and replaced it with this unit. It’s a game changer! The water is so hot, I needed to turn it down. We have it in a Tiki Bar by our pool.”
Customer Review: “I installed this in my boat and it worked flawlessly all summer. Easy installation and instant hot water.”
9. Electric Tankless Water Heater for Under Sink Use in Kitchen and Bathroom: 110V 3000W with Digital Display
This electric tankless water heater is designed for under-sink use in kitchens and bathrooms. It has a 3000W power rating on 110V, with a digital display for easy control. The ultra-thin design makes it stylish and space-efficient.
Key Features That Stand Out
- ✓ 3000W 110V power for efficient heating
- ✓ Digital LED display for temperature monitoring
- ✓ Compact and elegant ultra-thin design
- ✓ Multiple safety protections like water and electricity isolation
- ✓ IPX4 waterproof rating
Why We Recommend It
We recommend it for its modern design and safety features. The digital display adds convenience, and the waterproof rating ensures durability in damp environments.
Best For
Best for modern homes looking for a sleek under-sink water heater with digital controls for kitchens or bathrooms.
Pros and Cons
Pros:
- Sleek and compact design
- Easy-to-read digital display
- Strong safety features
- Good for point-of-use applications
Cons:
- May require a dedicated circuit due to high power draw
- Limited to low-flow uses
Customer Reviews
Customer Review: “Installation was straightforward, and the digital display is helpful. It provides hot water quickly for my kitchen sink.”
Customer Review: “Works well for my bathroom sink. The temperature control is precise, and the unit looks good under the cabinet.”
10. Tankless Water Heater Electric, Under Sink Instant Hot Water 110V 3KW, On Demand Point of Use for Kitchen and Bathroom
This tankless water heater is a 110V 3KW model for under-sink use. It features military-grade safety with a stainless steel tank and intelligent temperature control. Note that it requires specific circuit requirements for installation.
Key Features That Stand Out
- ✓ 3000W 110V power with strict circuit requirements
- ✓ Military-grade safety with 304 stainless steel tank
- ✓ Intelligent temperature control with ℃/℉ toggle
- ✓ Flow-temperature sync for efficiency
- ✓ Durable construction for long lifespan
Why We Recommend It
We recommend it for its robust safety features and durability. The intelligent controls help optimize performance based on water flow.
Best For
Best for users who prioritize safety and durability, and have the proper electrical setup for a high-power 110V appliance.
Pros and Cons
Pros:
- High safety standards with stainless steel build
- Smart temperature and flow adjustment
- Durable and corrosion-resistant
- Good for point-of-use hot water
Cons:
- Demanding electrical requirements (e.g., 27A+ breaker)
- May be complex to install for non-professionals
Customer Reviews
Customer Review: “It was not clear how much power the unit needs. It requires more than a normal household circuit, so check your wiring first.”
Customer Review: “After ensuring the correct circuit, it works well for my kitchen sink. The hot water is instant and consistent.”
Complete Buying Guide for Best 120 Volt Tankless Water Heater
Essential Factors We Consider
When picking the best 120 volt tankless water heater, think about power, flow rate, and installation. Power output in watts or kilowatts determines how much hot water it can produce. For 120V models, they’re usually for point-of-use, like a single sink. Flow rate is key—check how many gallons per minute (GPM) it can heat. In colder areas, you might need a higher power unit. Also, consider installation: some plug into outlets, others need hard-wiring. Always ensure your electrical system can handle the load.
Budget Planning
Prices vary from budget-friendly to premium. Expect to pay more for brands like Rheem or Stiebel Eltron, but they offer reliability. Don’t forget installation costs—if you’re handy, DIY can save money, but for complex wiring, hire a pro. Factor in long-term savings on energy bills, as tankless heaters are more efficient than tanks.
Final Thoughts
Choosing the right 120V tankless water heater depends on your specific needs. For a simple under-sink solution, go with a compact plug-in model. For whole-house or multiple uses, you might need 240V. Always read reviews and check warranties. Our top picks balance performance, price, and ease of use.
Frequently Asked Questions
Q: Can a 120 volt tankless water heater run a shower?
A: Usually, no. Most 120V models are for low-flow point-of-use applications like sinks. They lack the power to heat water fast enough for showers. For showers, you’d typically need a 240V unit with higher wattage.
Q: How do I install a 120 volt tankless water heater?
A: Installation varies by model. Some plug into a standard 120V outlet, making it easy for DIY. Others require hard-wiring to a dedicated circuit breaker. Always follow the manufacturer’s instructions and local codes. If unsure, consult an electrician.
Q: Are tankless water heaters more energy-efficient than tank models?
A: Yes, generally. Tankless heaters only heat water when you need it, reducing standby energy loss. This can save money on electricity bills over time, especially for frequently used points.
Q: What maintenance do 120 volt tankless water heaters need?
A: Minimal maintenance is required. Periodically check for leaks or mineral buildup, especially in areas with hard water. Some models have self-cleaning features. Refer to the user manual for specific tips.
Q: How long do 120 volt tankless water heaters last?
A: With proper care, they can last 10-20 years. Quality of materials and usage patterns affect lifespan. Look for models with good warranties for peace of mind.
We’ve explored the best 120 volt tankless water heaters available, from valve kits to under-sink units. Each product offers unique benefits for different needs. Remember to assess your hot water requirements, electrical setup, and budget before buying. Ready to upgrade your hot water system? Check out our top picks on Amazon for the best deals and start enjoying instant hot water today!
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