10 Best Instantaneous Under The Sink Water Heaters in The UK

Last updated on 31/08/2025

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Briwellna Electric Instantaneous Tankless Water Heater 5.5kW 220V, Instant Hot Water Heater with Digital Display for Kitchen Bathroom Sink Counter Under/Above Home Indoor (White)

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Why We Love It

Unlimited hot water on-demand.
Efficient, space-saving design.
Ensures multiple security protections.

Main Highlights

[On-demand, Umlimited Hot Water] Briwellna Non-Thermostatic Tankless Electric Water Heater is ideal for a single sensor faucet or a single metering faucet for handwashing and other fixed-flow applications.
[Compact Size Fits Almost Anywhere] This water heater is designed specifically with replacements in mind. The smaller dimensions (210mm×172mm×73mm)makes it easier to swap out your existing less-efficient water heater.
[Flexible Installation in Any Orientation] The product can be installed at any angle and the display will be automatically adjusted when the product is installed upside down.
[Save Energy and Time] Equipped with the latest integral cast aluminum heating technology, this water heater produces instant hot water without storing water, preheating devices or an attemperator, saving power consumption, water, time and space. It can be shut off by turning off water or power supply
[Multiple Security Protection] Smart protection functions protect the product from leakage, over-temperature, dry heating and over-pressure. We offer one-year warranty.
[Easy Installation] Coming with multi-language user's manual, it's easy to install the faucet without plumbers. Video of installation guadiance is available. It can be installed above or under the sink. Please make sure the water pressure required(0.04-0.8MPa) and your breaker panel to dedicate 25A(5500W) double pole breakers solely to the unit. The water connector size is 1/2". Fits both old style 1/2" hose connector and 3/8" water supply system(with adapters).

ThermoMate ELEX5.5 Instantaneous Electric Water Heater with LED Display, 5.5kW Hand Wash Water Heater for Basins Sinks, Over/Under Sink Water Heaters, ‎Hard Wire 220V

15% OffFree Shipping

Why We Love It

Instant heating, endless hot water.
Advanced flow control feature.
Convenient temperature control display.

Main Highlights

【2S INSTANT HEATING & ENDLESS HOT WATER】- Turn on the water tap and endless hot water will come out within 2 seconds on demands when require, hence you will never run out of hot water and only pay for what you really use. Savings of up to 50% on water heating costs.
【EXCLUSIVE ADVANCED FLOW CONTROL & WATER LEAKAGE PREVENTION】- Unique technology is applied to improve water flow and prevent any water from splashing or dripping. You can adjust the flow rate you want to meet your needs in any time. Maximum hot water flow rate: 3L/min
【FLEXIBLE INSTALLATION】- When inverting the installation, the numbers automatically flip over. When the electric washbasin is in operation, the LED displays the current water temperature in real time, so you can easily get hot water at the desired temperature. The temperature range of 35 to 55°C can be selected by touch control.
【EXCEPTIONALLY DURATION】- Built in high quality alloy bare heating element, it is corrosion-resistant and acid-resistant; flowing water prevents limescale from building up, which prolongs its service lifespan.
【TWO INSTALLATION APPLICATIONS OPTIONAL】- Functional for both over sink and under sink installation, display will reverse automatically. Act as primary heater, with water being injected from cold mains directly; Act as booster heater, with hot water being injected from a storage tank. It is free to connect to a mixer tap.Water Inlet and outlet sizes G1/2‘’

Bosch Tronic Comfort Compact Hydraulic Water Heater 3.5 kW, Ready to Plug, Under-Sink Device, Pressure- and Pressure-Resistant Connection, White/Grey

27% Off

Why We Love It

Compact design for small spaces.
Efficient hot water generation.
Robust and safe construction.

Main Highlights

Automatic, small instantaneous water heater, thanks to its compact design, ideal for a hand wash basin.
High efficiency in hot water generation: only the required amount of water is heated economically and quickly during the passage.
Thanks to the tubular radiator it is particularly robust and suitable for all water hardnesses. Tested safety by VDE testing institute. Ready-to-use construction, under-sink unit.
Box contents: device, plug cable, mounting rail.
Installation Instructions: Must be fitted by authorized professionals only.

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

13% Off

Why We Love It

Heats water incredibly fast.
Provides hot water instantly.
Durable stainless steel construction.

Main Highlights

【Fast Heating】 This instant water heater adopts advanced instantaneous heating technology, which heats up quickly and greatly saves time waiting for hot water. The single-piece compact insulation design not only reduces energy consumption, but also ensures a continuous supply of hot water. Whether you are washing up in the morning or bathing in the evening, you can turn on the water immediately and enjoy a comfortable living experience.
【On-Demand Water Supply】 This compact water heater eliminates the long wait for hot water at the sink, allowing you to get hot water on demand whenever you need it. Whether you're washing your hands, face or dishes, it's ready to use, providing convenience and comfort. Whether you are a domestic user or a commercial establishment, this water heater is the ideal choice for you.
【Quality Material】This under sink water heater is made of stainless steel tubes with excellent anti-pollution ability, which can adapt to a variety of complex water quality environments. Whether it is hard water or soft water, it can ensure the long-term stable operation of the water heater and extend its service life. High-quality material selection, so you can use it with confidence and peace of mind.
【Safety & Reliability】 This water heater adopts a one-piece moulding design, effectively preventing erosion in bathroom and kitchen environments. Over-pressure protection function: when the pressure in the liner exceeds the safety rated pressure, the safety relief valve will automatically release the pressure. Dry burn prevention function: when the liner dries out, the secondary insulation protection will immediately cut off the power supply and automatically stop working.
【Flexible Installation】 Compact in size, this small electric water heater can be easily placed in the kitchen, lounge, bathroom or anywhere else you need it. The exquisite design not only saves space, but also blends into various home environments and enhances the overall aesthetics. Whether it is wall-mounted or vertical installation, it can meet your personalised needs and make life more convenient.

VELPAX Mini Electric Water Heater, 10L Electric Instantaneous Water Heate,1500W 220V,Waterproof Under Sink Water Heater with Digital Display for RV Kitchen Bathroom

Free Shipping

Why We Love It

Instant hot water, no waiting.
Durable construction, long-lasting use.
User-friendly, easy installation process.

Main Highlights

【Electric Mini Tank Water Heater】- The Electric Mini Tank Water Heater,1500-watt heating system delivers instant hot water in seconds without preheating,with more safety protection such as anti-freezing protection,over heating protection, 10L of hot water can be output per minute. The maximum temperature raise is 158 °F.
【Durable and Long Service】- The internal materials of instant hot water heater electric 110v are made of high-temperature calcined layer and enamel layer, which have corrosion resistance, rust prevention,and anti-corrosion properties.Stainless steel heating tubes and built-in magnesium rods can effectively purify water quality and extend service life.Integrated stainless steel tank body and Polyurethane CFC-free filling layer ensure the stability of the tank body and excellent insulation.
【Super High Efficiency】- Small Hot Water Heater Energy efficient with plenty of hot water,also known as demand-type or instantaneous water heaters, provide hot water only as it is needed,our water heaters with thermal efficiency up to 90%,Instant hot water at the point of use, whenever needed,Also equipped with a high-definition intelligent digital LED display,effortlessly adjust the temperature between 86°F-158°F according to your preferences.
【Easy Assemble and Use】- This Electric Tank Water Heater,for 1/2" NPT water hose connection,with Leakage protection fitting 1/2" NPT, pressure relief valve, two 3FT hoses,10L small tank water heaters,Compact design,The product dimensions are 14.5 x 8.6 x 10.6 inches, can be wall or floor-mounted in a discreet location.
【Satisfaction Guarantee】- We feel confident that you will love our mini tank water heater. If there's something makes you unsatisfied, please don't hesitate to contact us. We would offer you 100% refund or a replacement within 3 months.

Bellanny Mini Electric Water Heater, 1.5KW 220V Electric Instantaneous Water Tap with 15L Water Tank, IP4X Waterproof Under Sink Water Heater with LCD Digital Display & Temperature Knob, UK Plug

Why We Love It

Instant hot water availability.
Compact and space-saving design.
Durable stainless steel construction.

Main Highlights

【Instantaneous Design】Instantaneous heating technology allows hot water to be available as it is turned on, no need to wait for a long time, greatly improving the efficiency of use. Compact one-piece insulation layer structure effectively reduces heat loss, reduces energy consumption, energy saving and environmental protection. Whether you are washing your hands, washing dishes or making tea, the electric water heater can quickly get the hot water you need.
【On Demand Water Supply】This water heater supports instant heating to meet your demand for hot water at any time. Whether you are washing dishes in the kitchen, washing hands in the bathroom, or brewing drinks in the lounge, you can achieve a ‘zero-wait’ hot water experience. Simple to operate and with a stable water supply, it is ideal for enhancing home comfort, especially for small homes or rental properties with limited space.
【High Quality Stainless Steel Heating Tubes】This small instant water heater is made of high quality stainless steel heating tubes with excellent anti-pollution and corrosion resistance, which can adapt to a variety of complex water environments and prolong the service life. Even in areas with hard water or high impurities, it can operate stably and is not easy to be clogged or damaged. Provide your family with a long-lasting, stable supply of hot water, and truly achieve peace of mind.
【Multiple Safety Protection】This water heater is built by one-piece moulding process, with solid structure and good sealing, effectively preventing the erosion of the internal components by the humid environment in the kitchen or bathroom. Meanwhile, it is equipped with an overpressure protection device: when the pressure in the inner liner exceeds the safety range, the automatic pressure relief valve will start to release the pressure, safeguarding the safety of the equipment and users.
【Compact and Flexible】 Small size and compact design, can be easily placed in kitchen cabinets, bathroom corners, under the counter in the lounge and any other space you need. this under sink water heater does not take up much space but is powerful, flexible and convenient to install, no need for complicated wiring or remodelling works. Suitable for homes, flats, dormitories, offices and other places, it is the ideal choice for you to enjoy hot water life anytime and anywhere.

wowspeed 1.5KW Electric Water Heater, 220V 7A Instant Water Heater with Digital Display, Under Sink Tankless Electric Water Heater Suitable for Showers, Water Heat for RV Kitchen Bathroom

3% Off

Why We Love It

Quick hot water anytime.
Compact and portable design.
Energy-saving and safe.

Main Highlights

【Instantaneous Water Heater】 Are you still worried about not having enough hot water when washing dishes? Our instantaneous water heater heats up quickly, saving heating time, with good insulation, providing you with a constant supply of warm water and automatic refilling. Single-piece compact insulation reduces energy consumption. Knob type temperature control makes your operation easier and more convenient
【Energy Saving and Safe Instantaneous Water Heater】Our energy saving under sink water heater is safe and effective. Fast heating reduces the long wait for hot water, get hot water on demand anytime. PREVENT DRY BURNING: When the inner liner is dry and dry, the secondary insulation protection immediately cuts off the power supply and automatically stops the work. INDICATOR LIGHT: When the machine is in the heat preservation state, it will light up a green light
【Safe Electric Water Heater】The electric water heater is made of stainless steel tubing, which is resistant to contamination and can adapt to a variety of complex water quality environments. When the pressure in the inner liner exceeds the safety rated pressure, the safety relief valve will automatically relieve the pressure to protect the liner and your safety. Note: When installing for the first time, please fill up with water first and then turn on the power to avoid burning the heating tube
【Friendly Design】Equipped with a high-definition LED digital display can show the water temperature, to avoid you or your family members being scalded due to high water temperature, to provide safety for your use. Mini electric water heater is lightweight and compact for tight spaces, energy efficient and large water output. Our water heater has a thermal efficiency of up to 90%, can provide hot water anytime, anywhere, and the heating time is only 8-15 minutes (depending on the climate)
【Wide Range of Application】This under sink electric water heater can be placed in tight spaces, suitable for most floor standing, shelf or wall mounted installations, perfect for any tight space, giving you easy access to instant and endless hot water. Can be installed in the kitchen, lounge, bathroom, caravan or anywhere else you want

Sararoom 1500W Electric Water Heater, 220V Mini Under Sink Water Heater with LCD Display and Temperature Knob, Instant Water Tap with 15L Water Tank for Kitchen, Lounge, Bathroom, UK Plug

Why We Love It

Efficient stainless steel construction.
Instant heating saves time.
Compact design saves space.

Main Highlights

【Efficient and Durable Stainless Steel Tube, Adapt to Various Water Quality】This small instant water heater adopts high-quality stainless steel tube inner liner, which has strong anti-pollution ability and is not easy to scale or rust, so it can easily cope with complex water environment and ensure that it is still clean and hygienic for long time use. Whether it is hard water, soft water or water with trace impurities, it can operate stably and provide safe and healthy hot water.
【Instantaneous Heating, Energy-Saving and Time-Saving more Efficient】This water heater adopting high efficiency instant heating technology, cold water instantly warms up without pre-heating. The compact single-piece insulation design effectively reduces heat loss and energy consumption, which is environmentally friendly and economical. Whether it's for early morning washing, daily hand washing or kitchen water, it can quickly provide stable hot water to meet your immediate needs.
【Supply Hot Water on Demand, Say Goodbye to Waiting Troubles】While traditional water heaters need to adjust the water temperature repeatedly, this electric water heater can accurately output suitable hot water, which is ready to use, eliminating the long waiting time in front of the sink. Whether it is a sudden need to wash hands, emergency kitchen water, or the trouble of adjusting the temperature before bathing, it can quickly respond to provide comfortable hot water anytime, anywhere.
【Compact and Exquisite, Flexible Installation Does not Take Up Space】Compact and beautifully designed, it can be easily installed in kitchens, bathrooms, lounges or anywhere hot water is needed. This water heater provides powerful hot water performance without taking up valuable space, making it ideal for small homes, flats, offices or rental properties. The concealed installation or wall-mounted design blends perfectly into the home environment, making it both attractive and practical.
【Safe and Reliable, Intelligent Protection is More Worrying】Equipped with intelligent overpressure protection system, when the pressure in the inner liner exceeds the safety value, the pressure relief valve will start automatically, avoiding potential safety hazards. High-quality materials and strict craftsmanship ensure long-term stable operation. Whether it's for daily use at home or in commercial scenarios, this under sink water heater can provide you with lasting peace of mind.

Instant Electric Tankless Hot Water Heater with Touch & Remote Control, 3KW 220V Mini Constant Thermostatic Heating Water Heater for Kitchen & Bathroom Sink, Digital Display (White)

Why We Love It

Endless hot water instantly.
Compact and easy installation.
Energy-efficient and cost-saving.

Main Highlights

🌊【Electric Water Heater On Demand】This Instant water heater provides endless hot water on demand and only as needed, no need to preheat, fast heating in 3-5 seconds, constant temperature after setting the temperature to maintain the best water temperature for you. The temperature can be adjusted by remote control and touch control, which is more convenient to use. This instant water heater is small in size, easy to install.
🌊【Specification】3000W, 220V Instant Hot Water Heater, UK standard plug with remote control; Standard 1/2 interface(inflow or outflow); The wire requirement is greater than 1.5㎡; Using water pressure: 0.04-1.2Mpa. Frequency: 50-60HZ; Adjustable temperature 30-55℃ (86-131°F), Waterproof grade IPX4, electronic large-screen display , the third gear power is adjustable.
🌊【Mini Tankless Hot Water Heater 】This electric water heater is more suitable for kitchen and bathroom sinks, providing a comfortable water temperature when you are washing your hands, dishes, face, and clothes. It is not recommended to use it in the winter shower, the water flow is small in winter, and generally needs more than 6500W to reach above 45°, but it can be used for bathing in spring, summer and autumn.
🌊【Safe to Use】Our electric tankless water heaters have been rigorously tested to ensure your safety. The electric and fluid systems are completely separated to prevent electric leakage and water pipe corrosion. It also has dry-burning protection, overheating protection and automatic power-off in inactive states.
🌊【Efficient and Energy-saving】It consumes low energy but is very efficient. The electric hot water heater works at the same temperature, and the power consumption produced by the four seasons is different, which can save your energy costs and 30-50 ℃ adjustable temperature meet your various needs.

Neulriscn Instant Water Heater, 5.5KW 220V Electric Tankless Water Heater with Shower Head, Constant Temperature LED Digital Display for Bathroom, Kitchen, Under Sink Tank, Household Indoor

Free Shipping

Why We Love It

Instant hot water anytime.
Smart temperature control feature.
Safe and durable design.

Main Highlights

【Electric Tankless Water Heater】Applied with 5.5KW heating system, the electric water heater supplies instant, consistent and endless hot water of 45℃ shortly. It is good idea to install this kind of tankless water heater electric a few ft away from the faucet or other feature, to get instant and sufficient hot water.
【Smart Temperature Adjustment】The tankless water heater features smart self-modulation, adjusting power input based on real-time water flow rate and temperature settings. When water flow decreases, the instant water heater reduces power to maintain your preferred temperature, avoiding scalding hot water. Optimal energy efficiency of 95% saves considerable electric charge.
【Effortless Temperature Control】The electric tankless water heater comes with a digital display and touch control panel, making temperature adjustments straightforward and easy. Just turn on the tap and let the smart tankless water heater handle the rest, combining simplicity with efficiency.
【Safe and Reliable】The instant hot water heater is equipped with inner water and electricity lines designed to run separately so as to avoid leakage or harm of scale build up. IPX4 waterproof, leakage protection, dry heat protection, automatic power-off in over-temperature and inactive states.
【Durable Mini Electric Water Heater】The instant hot water heater measures about 29 x 20 x 7cm; Rated voltage: 220V, Rated power: 5500W, Use water pressure: 0.1-0.6MPa, Heating material: 304 stainless steel, Temperature range: 25-55℃.
【Installation Tips】1. First pass water and then pass electricity, suitable for water pressure of 0.1-0.6MPa; 2. The power switch should be installed in a place; 3. It should be installed in a place with an indoor temperature of above 0℃, the hot water outlet should not be too far from the hot water usage point.

8.9

Excellent

We scanned 812 products

We reviewed these offers relevant to the Instantaneous Under The Sink Water Heaters within online retailers such as Amazon, eBay and other local retailers, ensuring we covered all major brands and models. The products we selected come from trusted brands like Briwellna, thermomate, Bosch Thermotechnik, Bellanny, VELPAX, wowspeed, Sararoom, AYYDS, Neulriscn, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best Instantaneous Under The Sink Water Heaters in the market, we considered we took a deep dive into 4061 online reviews , focusing on elements like user satisfaction, performance in real-world conditions, and long-term reliability. Our ranking also evaluates each review’s relevancy, authenticity, up-to-dateness and depth so that the comparison is more sound.

We concluded that:

The clear winner of our analysis is Briwellna Electric Instantaneous Tankless Water Heater 5.5kW 220V, Instant Hot Water Heater with Digital Display for Kitchen Bathroom Sink Counter Under/Above Home Indoor (White). We love many things about this product by Briwellna. What sets it apart from the competition is Unlimited hot water on-demand, Efficient, space-saving design, Ensures multiple security protections.
The best value product for most shoppers and where user satisfaction is continuously the highest is ThermoMate ELEX5.5 Instantaneous Electric Water Heater with LED Display, 5.5kW Hand Wash Water Heater for Basins Sinks, Over/Under Sink Water Heaters, ‎Hard Wire 220V by thermomate based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for Instantaneous Under The Sink Water Heaters and the best cost-to-value ratio is Bosch Tronic Comfort Compact Hydraulic Water Heater 3.5 kW, Ready to Plug, Under-Sink Device, Pressure- and Pressure-Resistant Connection, White/Greyat Bosch Thermotechnik with a 27% discount.
Our list of the best Instantaneous Under The Sink Water Heaters is updated regularly to reflect new releases and changes in product availability, so be sure to check back often for the latest rankings and discounts.

10 Best Instantaneous Under The Sink Water Heaters in The UK

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We scanned 812 products

We concluded that: