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Under Sink Water Heater Comparison - April 2026
Overview: Are you looking for an efficient and convenient way to get hot water in your home? An under sink water heater could be the perfect answer. Read our reviews to find out which one is right for you.
110V-120V 1440-1500W Small Under Sink Tank 2.5 Gallon Water Heater Hot Storage,Mini Instant Electric RV TR Trailer Kitchen Compact,Food Truck 2 PCs 16” Long 1/2”FIP Stainless Steel Hose (BI-2.5)
Model
Rheem 3.5kW 120V Point of Use Thermostatic Tankless Electric Water Heater
Model
Tankless Water Heater Electric 110V, 3000W Instant Water Heater Under Sink, On Demand Hot Water Heater Electric with Digital Display, Electric Mini Water Heater for Kitchen Bathroom Washin
Brand
BISELONG
Brand
Rheem
Brand
xwdzswgs
Reviews
4,888 reviews
Reviews
120 reviews
Reviews
1,280 reviews
Tech Specs
is electric
Yes
is electric
Yes
is electric
Yes
color
White
color
Gray
color
White
included components
T-tube, hose, safety valve
included components
RTEX-04T Tankless Electric Water Heater
included components
1 × Mini Instant Hot Water Heater, 1 × English Manual, 4 × Screws
maximum temperature
149 Degrees Fahrenheit
maximum temperature
140 Degrees Fahrenheit
maximum temperature
131 Degrees Fahrenheit
wattage
1500 watts
wattage
3500 watts
wattage
3000 watts
maximum operating pressure
108 Pound per Square Inch
maximum operating pressure
150 Pound per Square Inch
maximum operating pressure
1.2E+3 Kilopascal
efficiency
98%
efficiency
Highly Efficient
efficiency
Efficient
product dimensions
11.2"W x 11.8"H
product dimensions
10.88"W x 5.88"H
product dimensions
4.33"W x 7.87"H
item weight
9.5 pounds
item weight
4 pounds
item weight
2.44 pounds
special features
Overheat Protection, Rustproof
special features
[IN] Space-saving Design, Energy-saving
special features
Dry Combustion Protection, LED Display, Lightweight
Here are the top 3 recommended products with more information to help you find the right product for you
9.7
1
BISELONG
110V-120V 1440-1500W Small Under Sink Tank 2.5 Gallon Water Heater Hot Storage,Mini Instant Electric RV TR Trailer Kitchen Compact,Food Truck 2 PCs 16” Long 1/2”FIP Stainless Steel Hose (BI-2.5)
Why we love it
Highly energy efficient.
Compact and space-saving.
Quick and easy installation.
Main highlights
【Safety protection】 Certified by CE, ROHS, and FCC for safety and reliability. Electrical insulation at the entrance/exit. Leak proof plug. High quality insulation material with high temperature limiting device and automatic temperature control. Multi layer protection ensures safety.
【Rapid Temperature Recovery】The BISELONG water heater is made from 0.04inch (1.1mm) thick 304 stainless steel and uses laser welding technology, ensuring it never rusts, withstands high pressure, and doesn't leak! The 1500w "L" shaped heating element increases the heat exchange area with the water in the tank, speeding up the heating process and eliminating the long wait for hot water beside the sink! (It can heat up to your desired temperature in 8-15 minutes for up to two sinks at a time).
【Product Upgrade】On June 25, 2023, the product was fully upgraded—the water heater’s 304 stainless steel lining will be thickened to 0.04 inches (1.1 millimeters), providing a longer service life, and the unit weight increased to 8.4lbs (3.8 kilograms). The insulation material and foam insulation were replaced, improving the Improved insulation effect, making it more energy-efficient!
【Note】Due to the improvement in product quality, the warranty period for water heaters purchased after July 4, 2023, is 2 years. According to buyer feedback, some water heaters had quality issues. Based on the photos provided by the buyers, it was found that they mistakenly installed the pressure relief valve at the outlet (red end)!
【Energy-Saving Smart Inverter】Automatically keeps water warm and stores hot water. The compact 2.5-gallon tank can be installed under the sink, with a thermal efficiency of 99% and a maximum temperature of 149℉. It has a built-in smart chip that heats to the temperature you set, and when it reaches the desired temperature, it automatically insulates to keep the heat in.Additionally, it helps reduce scale buildup!
【Easy Installation】Water connection tube is 1/2''FPI, electrical requirements: 120v (AC), single voltage: 1500w with plug connection wire, maximum water pressure 108PSI, recommended circuit breaker rating: 15Amps, BISELONG electric water heater can be installed on walls or floors, in a concealed position.
【Customer Service】If there are any quality issues with the product or problems with installation, you can contact us at any time. Our customer service is online for 16 hours!！
【Compact Design Saves Space】BISELONG has always been committed to original design! Its compact, square design makes this water heater ideal for homes, under sinks, RVs, food trucks, and more. It can be installed in cabinets or used in conjunction with washing machines and dishwashers. The product dimensions are 13.0''L x 11.4''W x 10.6''H inches.
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9.6
2
Rheem
Rheem 3.5kW 120V Point of Use Thermostatic Tankless Electric Water Heater
Why we love it
Compact and space-saving design.
Efficient and energy-saving operation.
Consistent hot water supply.
Main highlights
SAVES SPACE: Ideal for low flow point-of-use applications, such as in a bathroom, office breakroom, wet bar, or garage. The compact size of the water heater is up to 98% smaller than a standard electric water heater.
INSTALLATION: Designed to be mounted in an upright position with the inlet and outlet water connections at the bottom of the unit for ease of installation with no venting required.
ELECTRICAL REQUIREMENTS: 1 x 30 AMP Double Pole Breaker Required. Product installation hard wired to 120 volts requiring a 30-amp breaker.
EASILY ADJUSTABLE: Thermostatic temperature controls in 1-degree increments ranging from 80 to 140 degrees Fahrenheit for on-demand, consistent hot water.
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9.5
3
xwdzswgs
Tankless Water Heater Electric 110V, 3000W Instant Water Heater Under Sink, On Demand Hot Water Heater Electric with Digital Display, Electric Mini Water Heater for Kitchen Bathroom Washin
Why we love it
Heats water instantly.
Compact and space-saving.
Easy temperature control.
Main highlights
SAFETY INTELLIGENCE RELIABLE - This under sink water heater has multiple protection functions. IPX4 waterproof, leakage protection, dry-burning protection, automatic power-off in over-temperature and inactive states. Tankless hot water heater electric can meet your outlet temperature requirement. Large water flow means low temperature and small water flow means high temperature. TIP: Install vertically to avoid malfunction of the heating elements (E2).
QUALITY WARRANTY & IMPORTANT NOTE - We provide a 24-month warranty for the electric water heater tankless. If you encounter any after-sales issues regarding the small hot water heater, you can always contact our electric tankless water heaters support team. Tip: This electric hot water heater is recommended to be connected with wires with a cross-sectional area of ≥ 2.5 square millimeters, and connected to trip switches of over 32a for use.
MINI INSTANT HOT WATER HEATER - This 110 volt water heater is equipped with state-of-the-art technology, with 3000W power, LED display. The electric tankless water heater 110v can raise the water by 82° F (28°C) (0.3GPM) -131° F( 55 °C) (0.5GPM) in 3-5 seconds, saying goodbye to long waiting times for hot water. The tankless electric water heater can set Fahrenheit or Celsius degrees by holding a power button for 6 seconds.
LIGHTWEIGHT PORTABLE DESIGN - This small water heater compact design, is suitable for installation in the bathroom, kitchen under the sink, etc. The on demand water heater adopts a wall-mounted design, freeing up valuable space for your home, enjoy hot water at any time. This instant hot water heater under sink qualifies for ETL standard, you can expect the outstanding performance of this point of use water heater in the coming years.
EASY TO INSTALL AND APPLICATION - This under sink instant water heater comes with premade fixing screw holes, an English manual, and 1/2 inch NPT standard interface. This small electric water heater is ideal for spaces such as kitchens, apartments, bathrooms, RVs, and camping. The comfortable water temperature generated by this 110V water heater is suitable for cleaning food, bowls, clothes, face, hands, etc.
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Under Sink Water Heater Buyer's Guide
Written by Ryanne Brown
Intro
Under sink water heaters are a great way to get on-demand hot water in your kitchen or bathroom. These units are attached to the sink and connected to the existing hot water line, allowing you to have instant hot water without having to wait for the water to heat up in a tank. Before you buy an under sink water heater, there are some important features to consider so you can find the best model for your needs.
Capacity
One of the most important features of an under sink water heater is its capacity. You should look for a unit that can provide enough hot water for your needs. Some units come with a built-in tank, while others are tankless and provide an unlimited supply of hot water without having to wait for the water to heat up. Consider the size of your family and the number of fixtures in your home when choosing a unit.
Type
Under sink water heaters come in two different types: electric and gas. Electric models are the most common and are generally more energy-efficient than gas models. Gas models require a direct connection to a gas line, which may be more expensive to install. Consider your energy source when choosing a unit.
Temperature Range
The temperature range of an under sink water heater is also important. Look for a unit that can provide a wide range of temperatures so you can adjust it to meet your needs. Some models come with a digital thermostat that allows you to set the exact temperature you want.
Energy Efficiency
Energy efficiency is another important feature to consider when buying an under sink water heater. Look for a unit that has an energy-saving mode so it can save energy when not in use. Additionally, look for a unit that has a high energy efficiency rating, which will help reduce your energy costs over time.
Installation
Finally, you should consider the installation process when choosing an under sink water heater. Some models require professional installation, while others are designed to be installed by the homeowner. Consider how much time and effort you are willing to put into the installation process when making your decision.
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9.7
1BISELONG
Highly energy efficient.
Written by Ryanne Brown
