Advertising Disclosure Undersink Water Heaters Comparison - August 2025
7 Best Undersink Water Heaters In the UK
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service levels, popularity trends, and more. The rankings reflect our opinion and should be a good starting point for shopping. By purchasing the products we rank, you’ll get the lowest price we found while we may receive a commission at no cost to you, which will help us continue to provide you with value.
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| 1 Best Choice  9.7Exceptional | 2 Best Value  9.4Excellent | 3  9.3Excellent | 4  9.2Excellent | 5  8.9Very Good | 6  8.7Very Good | 7  8.4Good |
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ModelAriston ANDRIS LUX ECO 15 L Undersink Electric Water Heater 2.5kW with A Titanium Enamelled Tank, A Class Erp Rating, Copper Heating Element, Manufactured To Be Installed In UK - 3100722, White | Model Ariston ANDRIS R 15 L Undersink Electric Water Heater, 3kW, Control Unit, B class ErP rating, Economy “E” Setting, Manufactured to be installed in UK - 3100834. | Model Mini Electric Instant Water Heater for Sink, Stainless Steel On-Demand Small Vented Undersink Water Heater, 5500W 220V Point-of-use Compact Geyser for Home, Kitchen, Bathroom, Garage(Silver) | Model 2KW 220/240V UK Plug 8L Small Under Sink Tank, Thermal Storage Water Heater, Mini Tankless, Under Sink, Electric RV TR Trailer Kitchen Compact Point of Use | Model Ariston Water Heater Andris Lux Undersink 10L 2kW Electric Storage | Model Redring RP1 Powerstream 9.5kW Unvented Instantaneous Water Heater (45-793201) | Model Bellanny Mini Electric Water Heater, 1.5KW 220V Electric Instantaneous Water Tap with 10L Water Tank, IP4X Waterproof Under Sink Water Heater with LCD Digital Display & Temperature Knob, UK Plug |
BrandAriston | Brand Ariston | Brand WARMCITY | Brand FVSTR | Brand Ariston | Brand Redring | Brand Bellanny |
Reviews | Reviews  | Reviews | Reviews | Reviews  | Reviews | Reviews |
Tech Specs | ||||||
item weight 8.46 kg | item weight 7.5 kg | item weight 1.35 kg | item weight 3.7 kg | item weight - | item weight - | item weight 4.24 kg |
product dimensions 34.2 x 36 x 38.5 cm 8.46 kg | product dimensions 34.6 x 34.6 x 38.5 cm 7.5 kg | product dimensions 6.5 x 6.5 x 2.4 cm 1.35 kg | product dimensions 24 x 24 x 33.48 cm 3.7 kg | product dimensions - | product dimensions - | product dimensions 26 x 26 x 28 cm 4.24 kg |
color White | color Silver, Black | color Silver | color White | color Copper | color - | color White |
customer reviews4.5 4.5 out of 5 stars 123 ratings 4.5 out of 5 stars | customer reviews 4.4 4.4 out of 5 stars 56 ratings 4.4 out of 5 stars | customer reviews 5.0 5.0 out of 5 stars 2 ratings 5.0 out of 5 stars | customer reviews 3.9 3.9 out of 5 stars 113 ratings 3.9 out of 5 stars | customer reviews - | customer reviews - | customer reviews 4.7 4.7 out of 5 stars 4 ratings 4.7 out of 5 stars |
included components Pressure relief valve, dielectric junctions, wall bracket, installation manual, warranty certificate | included components - | included components user's manual, accessory | included components - | included components - | included components - | included components Electric Water Heater |
voltage 240 Volts | voltage - | voltage - | voltage 120 Volts AC | voltage - | voltage - | voltage 220 Volts |
special features Fast Heating | special features Fast Heating | special features - | special features Fast Heating | special features - | special features - | special features - |
Available On | Available On | Available On | Available On | Available On | Available On | Available On |
Our Top 3 Picks
Here are the top 3 recommended products with more information to help you find the right product for you
9.7
1Ariston16% OffAriston ANDRIS LUX ECO 15 L Undersink Electric Water Heater 2.5kW with A Titanium Enamelled Tank, A Class Erp Rating, Copper Heating Element, Manufactured To Be Installed In UK - 3100722, White
Why we love it
The Andris Lux Eco has a first in class ErP rating of A across all models.
The Eco Evo function saves up to 15 on your energy bill by remembering when and how much hot water you use.
The monthly anti legionella function eliminates the risk of legionella bacteria developing.
Main highlights- “Eco Evo” function: Thanks to the ECO EVO function, Andris Lux Eco remembers when and how much hot water you use. In this way the function will not only provide hot water efficiently, buti t will also and above all saving up to 15 Percentage on your energy bill
- Water heater designed and manufactured to be installed in UK
- Titanium Enamelled TankEnhanced Anti-Corrosion: With its proprietary titanium tank engineering, the Andris Lux Eco boasts exceptional durability and an extended product life. In addition, with its robust 4 bolt flange and copper heating element, this efficient water heater offers improved protection against water corrosion
- Ideal Installations: Medical Environments Laboratories School Facilities
- Fully UKCA certified to be installed in the UK Market
- First in Class ErP rating “A” across all models: With its electronic temperature control and its Eco Evo Function, the Andris Lux Eco is an energy efficient electric water heater boasting an “A” ErP energy rating across the whole range
- Eco Display: The unit’s smart, user-friendly display is easy to use and provides precise electronic temperature control, allowing the user to set the desired temperature for every need. The button “ECO” indicates when the Eco Evo Mode is activated and the LED indicator provides a visual guide to the water temperature inside the tank. In yhis way, you can have the hot water you need, when you need it, without any effort
- Anti-legionella function for total peace of mind: Once a month, this mini-tank electric water heater automatically increases the water temperature up to 65°C, in order to eliminate the risk of legionella bacteria developing. Ideal for applications such as hospitals, schools and care homes
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9.4
2Ariston30% Off
Ariston ANDRIS R 15 L Undersink Electric Water Heater, 3kW, Control Unit, B class ErP rating, Economy “E” Setting, Manufactured to be installed in UK - 3100834.
Why we love it
Durable titanium enamelled tank.
Energy-saving economy setting.
Precise temperature control.
Main highlights- “B” class ErP rating
- Water heater designed and manufactured to be installed in UK
- Titanium enamelled tank for durability: This premium quality water heater the best tank protection with the properties of titanium, wich constitutes a perfect shield against corrosion. Every single component is developed to ensure longlasting high performance with the guarantee of Ariston Brand.
- Maximum Comfort: Andris series products are able to keep the water hot for a long time thanks to the thick high-density polyurethane insulation placed in the tank and the outside of the water heater. It provides an effective barrier against heat losses, optimizing both the performance of the product and the users’ comfort. The models of the Andris series are equipped with an immersion thermostat, which allows a very precise adjustment of the water temperature, heating it to the desired point.
- Installation kits to be purchased separately
- Economy' setting on the dial to optimise comfort and energy saving
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9.3
3WARMCITY
Mini Electric Instant Water Heater for Sink, Stainless Steel On-Demand Small Vented Undersink Water Heater, 5500W 220V Point-of-use Compact Geyser for Home, Kitchen, Bathroom, Garage(Silver)
Main highlights- Intelligent Frequency Conversion Design: Indulge in the convenience of our intelligent electric water heater, featuring a cutting-edge frequency conversion design. Easily regulate the water temperature to suit your preferences, from a refreshing 20°C to a warm 50°C. In spring and summer, you’ll appreciate its energy-saving efficiency without any sauna-like heat, ensuring a gentle, low-power performance. As the weather turns cooler, our heater swiftly delivers high-power, rapid heating, letting you enjoy hot water without the waiting times typically associated with traditional systems.
- Efficient and Effortless Hotness: Unlike traditional tank-based systems that store and reheats water, this tankless model heats water on-demand. This means the water is instantaneously heated as it flows through, ensuring you never have to wait for tepid water again. It saves you energy by only consuming power when you’re actively using it, promoting eco-friendliness and cost-effectiveness.
- Durable Construction and Maintenance-Friendly: Crafted from high-quality stainless steel, this heater is built to withstand daily use. With a tankless design, you don’t have to worry about regular water storage maintenance. The compact nature also simplifies cleaning, as there’s no hard-to-reach tank to clean or replace.
- Digital Display: Unleash the convenience of our state-of-the-art electric water heater, where a user-friendly digital display comes to the fore. Its intuitive interface prominently displays the current temperature, granting you the precision you need for tailored water temperature control at a glance. This sleek design ensures a seamless experience, bringing control and comfort to your daily routines.
- Compact Design: This tankless water heater has a sleek, water heater for sink,cylindrical shape that is ideal for space-constrained areas. The cylindrical shape optimizes vertical space, allowing you to maximize available area. Its compact size enables installation in tight spaces or under sink installations, freeing up valuable storage and counter space. This makes it an ideal choice for small apartments or homes with limited room.
Our ranking system
The TopChoice.co.uk Team selects top-of-the-line items from a wide selection and conducts rigorous evaluations on almost all the products available on the internet. We rank each product based on how well it matches our criteria.We can ensure that the product is well-tested with the help of our expertise, experts, and artificial intelligence technology. TopChoice.co.uk requires consistent care for the products we review, ensuring that our assessments are always accurate and up to date.
Features
Our team of experts analyzes key attributes, capabilities, significance, and many more depending on the type of product to determine its effectiveness.
Consumer Reviews
We ensure an evaluation of the ratings using references all over the internet for each product. With the help of our AI technology and professional review teams, we give weight to the worth of individual user experiences.
Popularity
Popularity is an important criterion in choosing a product. Several factors contribute to the popularity of the products on our site, including prestige, relevance, reputation, news, and more.
Value for money
TopChoice.co.uk compares product attributes to price, examines tech specs, ratings and reviews, and more.When compared to other criteria, does the pricing seem reasonable? In order to provide genuine value for money, our team must answer that question with advanced calculations.
Value for money
TopChoice.co.uk compares product attributes to price, examines tech specs, ratings and reviews, and more.When compared to other criteria, does the pricing seem reasonable? In order to provide genuine value for money, our team must answer that question with advanced calculations.
