The 3 Under Sink Water Purifiers In India Reviews and Buying Guide In India

A water purifier has become a necessity in every household. However, one issue that many users complain of is the lack of proper space to install it in the kitchen. An under-the-sink water purifier can come to the rescue in such scenarios.

An under-counter or under sink water purifier is similar to a regular RO water purifier. The only difference is rather than wall mounting, you can install it under the sink counter.

They are designed specifically so that you can install them with built-in sinks that you will mostly find in modern kitchens. Before buying an under-the-sink water purifier, consider the following factors.

Purification Technology:

Along with sediment and carbon filters, all the under the sink water purifiers use only RO, UV, or both RO+UV/UF technology to purify water.

If the water supply at your home is hard with higher TDS levels, you should go ahead with an RO purifier. If the water is hard and if it also contains disease-carrying bacteria and germs, you should buy a purifier with RO+UV technology.

Storage Capacity:

The minimum storage capacity of a water purifier should be 5-7 liters. This will make sure that drinking water is available all the time.

Size/Compact Design:

It becomes an important factor if there is a storage issue in your kitchen. Hence, buy a compact model that can be easily installed under the sink without consuming too much space.

Water pressure and cartridge life are some other factors that also play an equal role in deciding the quality of the under-sink water purifier. You can check our buying guide to learn more about them.

We have also shortlisted some of the best under-sink water purifiers available in India. Let’s have a look!

3 Under Sink Water Purifiers In India

Under Sink Water PurifierFilter TypeWarrantyBuy Now
Kent Excell Water PurifierRO + UV/UF + TDS CONTROLLER1 yearCHECK ON AMAZON
A.O Smith  Z2 + Water PurifierRO + MIN-TECH1 yearCHECK ON AMAZON
Sterling Plus Water PurifierRO + UV + UF + TDS1 yearCHECK ON AMAZON

3 Under Sink Water Purifiers In India Reviews

1. Kent Excell Water Purifier


Kent is the most successful Indian brand that is providing the best service to its customers worldwide. It offers an exciting range of healthcare products and home appliances includes Water Purifiers, Air Purifiers, Vacuum Cleaner, and Modern Kitchen Appliances.

The Kent Excell water purifier has a capacity of 7 liters with the innovative purifying technology under RO + UV/UF + TDS Controller. The water purifying speed is 15 liters per hour. The storage capacity is certified food-grade plastic.

The TDS controller checks the Total Dissolved Salts in the water. The water purifier installs on the TDS level in between 500 to 2500. A piece of advice from our side is to check the TDS of your water source.

The water purifying technology is RO + UV + UF + TDS mineralizer water purification. The double purification of RO + UV removes the dissolved impurities. The TDS control system retains the essential minerals that make the water tasty to drink.

The filter change alarm and UV Fail alarm with Computer controlled operation that will keep you alert about the filter change. Also, you can pre-set time the alarm, and it is audible.

The spin-welded RO membrane housing prevents tampering. The purifier is fully automatic with auto-start and auto-off.

Even if the power cuts, you can take out the water from the storage tank.

Verdict: If the filter does not change within the next 60 hours after the alarm, the water purifier stops working. For every liter of water purifier, 650 ml of water filters out of the machine. It encourages to save the water in a utensil and use it for cleaning utensils, washing clothes and watering plants.

The water purifier box contains an installation kit and user manual. You have to call on the customer care, the mechanic will come to your house and install the purifier.


  • Double Purification
  • TDS mineralizer
  • Good storage capacity
  • Easy to install
  • Water available even in the absence of electricity
  • Free installation with one-year free service
  • One-year warranty


  • High-maintenance cost

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2. A.O Smith  Z2 + Water Purifier

ao smith

The A.O Smith Z2+ Under the Counter RO + MIN-TECH Water Purifier. It has 5 liters of storage capacity that is small in size for small families or office. The material of the tank is grade ABS, that protects the water for a longer time.

The company offers you free installation, in this case, you do not have to worry about how will you install it. It easily fits under the counter.

Before buying a water purifier, kindly check the TDS level of that area, depending on that you can buy the water purifier. When the water quality is good, it has a low TDS level. In Z2+ the TDS level up to 2000ppm and hardness up to 400 ppm is applicable.

The water purifier has six-stage of purifications:

Stage 1: Pre-Filter

Stage 2: Sediment Filter

Stage 3: Pre-Carbon Filter

Stage 4: RO Membrane

Stage 5: SCM- Tech (Silver Activated Post Carbon)

Stage 6: MIN-TECH: The mineralizer technology adds essential minerals like calcium and magnesium back into the water. While processing, the water losses its minerals, and MIN-TECH fulfills the deficiency.

The Patented SSM technology is unique as the side stream RO membrane is suitable for both low and TDS levels of water. It helps to improve the recovery and minimizes the wastage of water in purification.

The water comes out from a gooseneck faucet that is convenient in use. The digital display makes it easy to understand the digits and gives an intelligent display for information. After all, you do not have to keep a reminder for the filter change because the advance alert lets you know the RO membrane or other filters need replacement.

The product certified by WQA against NSF/ANSI 58 standards for material requirements.


  • Easy to use
  • Easy to install
  • Good storage capacity
  • Enhances the flavor
  • Six stages purification
  • Value for money
  • One-year warranty


  • Expensive in its price range

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3. Kent Sterling Plus Water Purifier


The Kent Sterling Plus has RO, UV, UF, and TDS controller. It is under the sink water purifier.

The water purifier has an elegant smart design that is ideal for the under-the-counter installation. Also, it is suitable for the side-by-side placement adjacent to the refrigerator for effective space utilization.

The mineral RO technology retains the essential natural minerals that filter out from the purified water. The TDS controller helps in making the drinking water tasty to drink.

Double Purification by the sterling plus that is fully automatic, which allows the purifier to begin the purification process whenever the water purified level falls from the maximum level.

It has a 6-liter inbuilt hydrostatic storage tank that provides a continuous supply of purified water even if in the power cut.


  • Easy to install
  • Double water purification
  • Added minerals
  • Enhances the taste
  • Space saver
  • Value for money
  • One-year warranty


  • Missing power and water level indicator

Buy Now at Amazon

Factors to Consider Before Buying an Under-Sink Water Purifier

While buying an under-sink water purifier for your home, there are many essential factors that you need to consider so that you buy the best one. Some of these factors are as follows:

1. Purification Technology:

Along with sediment and carbon filters, most of the under-the-sink water purifiers use only RO, UV, or both RO+UV/UF purification technology. Since the options are limited, you must understand which technology is going to be most suitable to purify the water supply at your place and then buy accordingly.

To do so, you will first have to test the quality of the water that you get at our place.

If you get a hard water supply and if the TDS levels are high, you must go ahead with an RO water purifier. If the water is hard and it also contains bacteria and germs (disease-causing), we would suggest you to go ahead with a RO+UV purification technology.

2. TDS Controller/Mineral Booster:

You must make sure that the RO or RO+UV under sink water purifier that you have selected comes with a TDS controller and a mineral booster.

It is very helpful in controlling the TDS levels in the water and in retaining essential minerals that are often removed while RO water filtration. It also helps in maintaining the pH levels of water, which, in turn, enhances the taste of the drinking water. It also enriches the drinking water experience.

3. Storage Capacity:

You should buy a water purifier with a minimum storage capacity of 7-12 years. It will ensure that pure drinking water is available for you always.

You will not run out of water even while there is an electricity shortage at your place.

4. Size/Compact Design:

The size of the under-sink water purifier plays a major role too, especially if there are space constraint issues in your kitchen. These purifiers are installed under the sink or below the kitchen counter. Hence, you must buy a purifier with a compact design so that it can be installed easily without consuming too much space.

5. Water Pressure:

You should get a glass of drinking water immediately rather than waiting for a long time. Thus, considering the water pressure is equally important. When compared to the conventional water purifiers, the water pressure offered is much higher by the under-sink water purifiers.

6. Cartridge Life:

The cartridge that comes with every water filter has a certain lifespan. While some cartridges need to be changed every 6-8 months, some cartridges can be used for up to 3 to 5 years.

While buying an RO purifier, ensure that the membrane comes with multiple stages of pre-filters. However, you will still have to change the pre-filters after every few months whereas the RO membrane can work efficiently for up to 2 to 5 years.

Even though most good brands provide a good cartridge life, you might have to replace them frequently due to water quality. Hence, make sure that the water purifier that you have selected provides a good cartridge life.

7. Maintenance:

The water purifier that you are buying should be easy to maintain. It should be easy to clean and the process of changing filters or cartridges should be easy too.

8. Installation:

The installation of the under-sink water purifier should be done by the technician associated with the brand.

Its installation needs some additional arrangements including a power socket and a tap with a constant water supply beneath the sink. These arrangements need to be done before installing the water purifier.

9. Ease of Installation:

As an under the sink water purifier dispense drinking water via a tap, you must make sure that it comes with a tap or faucet. If the water purifier does not come with a tap, you will have to buy it separately.

10. Faucet Type:

A faucet is another important requirement of an under-counter water purifier. Make sure that the water purifier that you are buying comes with a swivel-shaped or gooseneck faucet that can be installed on the sink, beside the tap.

A swivel shaped faucet allows free flow of drinking water and prevents any splashing. You can place the water bottle on the sink, under the faucet and wait till it is full. It prevents any mess in the kitchen.

11. Mode of Operation:

The mode of operation of an under-counter water purifier should be automatic. Make sure the water purifier comes with an auto shut off feature. It will ensure that the water purifier shuts off automatically when it is not in use for more than ten minutes. The water purifier should also be able to fill the tank automatically whenever you use some water. It will ensure that the tank is always full.

12. Self-Cleaning System:

A self-cleaning system is an additional feature that you get in most under sink water purifiers. With the help of this feature, the purifier cleans itself automatically and does not require any intervention from you.

It is helpful in preventing the deposition of dissolved solids such as calcium and magnesium over the membrane. Hence, it ensures the longevity of the water purifier and intends to provide a continuous flow of pure drinking water.

13. Error Alerts:

Some of the common error alerts offered by water purifiers are filter change alarms and UV fail alarms. It is beneficial to opt for a water purifier that offers these features as it will notify you whenever it is time to change the UV lamps and filters to ensure you get safe drinking water at all times.

14. Brand and Quality:

While buying a water purifier, you must always select one from a good brand as they ensure good quality over the low or mid-range brands that end up providing faulty products to the users.

15. Price:

Price is another important factor that you need to consider before buying an under sink water purifier. By cost, we don’t mean just the initial buying cost of the product. Instead, it also includes the overall maintenance cost and the price of filters that you will have to change regularly. Hence, you should calculate this beforehand and then make a choice accordingly.

16. Warranty:

Most brands offer a warranty of 1 year with the water purifier. Some brands provide a warranty on only electrical parts of the water purifier. Check what all it covers under the warranty and buy a product that offers the best warranty period with good after-sales service.

Types of Under-the Sink Water Purifiers:

There are two types of under-the-sink water purifiers available in the market: Inline filters and regular water filters. Let’s learn about them in detail:

1. Inline Filters:

The inline water filters feature a single cartridge that is installed using the push fittings along with the regular water source.

Even though the installation of these filters is a bit tricky, they allow you to use water from the sink tap while the water is flowing through the purifier.

2. Regular Filters:

The regular water filters compulsorily require a dedicated or separate filter tap. To install the second tap to get filtered water, you can use a T-connector.

Whatever type of filter you are choosing, you must make sure that you are buying the best under the counter RO water purifier with a TDS controller.

How Does an Under Sink Water Purifier Works?

Similar to a regular water purifier, an under-sink water purifier also uses the same mechanism. The only major difference between both the types of water purifiers is an under-sink water purifier is installed under the counter or sink that is away from the sight of the users.

  • They work using either RO or RO+UV water purification technology. The water passes through the RO membrane first and then it is disinfected in the next stage via a UV disinfection column.
  • These under sink water purifiers even use sediment and activated carbon in the form of pre- and post-filters and remove coarse particles and chlorine. They also remove bad odor and taste from the drinking water.
  • Thus, an under sink water purifier functions like any regular RO, UV, UF, or RO+UV/UF water purifiers and provide safe and healthy drinking water to you.

Things That Need to be Made Before Installing an Under Sink Water Purifier

Before installing an under-sink water purifier, you might have to make certain arrangements beforehand. The below-mentioned list can be helpful in easy installation of the water purifier:

  • An under-sink water purifier requires a constant supply of running water. Hence, there must be a tap under the sink and beside the water purifier. If there is no tap available, you will have to call a plumber and get it arranged. You can connect it to the main tap on the sink so that you get a continuous water supply.
  • The water purifier requires a separate faucet that should either be installed on the sink or on the kitchen top. To fit the faucet on the dedicated location, you/the technician will have to make a hole. Ensure that the technician is drilling the hole during the installation or else you will have to arrange this set up on your own that can be a tedious task.
  • The area below the sink should be clean and hygienic.
  • There should be a power socket under the sink as the under-sink water purifier operates on electricity.
  • It also requires a proper drainage system as there will be some amount of water that will be collected during the purification process. Hence, it will require a water outlet for waste water to go out.

Advantages of Buying an Under-the-sink Water Purifier:

Along with providing safe drinking water to the users, there are many other advantages of buying an under-sink water purifier. They are as follows:

  • These water purifiers are ideal for kitchens with space constraints as they feature a compact model and design. They can be installed in a cabinet under the water sink. They take up less space and hence, save a lot of space in the kitchen.
  • The flow rate of under sink water purifiers is high. These water purifiers use a hydrostatic tank due to which the flow and pressure of water are good. A hydrostatic tank maintains optimal pressure, resulting in a higher flow rate of water. This ensures that you can fill a bottle within 10 to 15 seconds.
  • As they are hidden and away from your sight, these water purifiers don’t mess with the look or interior of your kitchen.
  • An under-sink water purifier features a faucet that is installed beside the tap on the sink. Hence, it prevents the spilling of water on the floor. You can simply keep the bottle on the sink and wait for it to fill.
  • They require very little maintenance.
  • The cartridge of the filter comprises of the cation resin. It removes most of the calcium and magnesium present in the water. It also helps in lowering the amount of limescale build-up on the surface of the sink.

Disadvantages of Using an Under Sink Water Purifier

Along with a set of advantages, there are some disadvantages of under sink water purifier too. The disadvantages of using an under-sink water purifier are as follows:

  • To provide clean drinking water, the purifier requires a separate faucet.
  • The external installation might cost you a bit extra and it might not be that durable too.
  • Its installation requires a separate electric wall socket below the sink. Check if you can install the socket beneath the sink as you can fix the motor easily, without consuming extra space.
  • Leakage proofing is very important to avoid any accidents. You will again have to spend some extra money on this.
  • If you have not installed the purifier properly, it might lead to water leakage, Hence, it is suggested to call a certified technician to fix the pipeline and install the filter properly.

Frequently Asked Questions

1. How often do I need to change the filter of under sink water purifier?

It depends completely on the filtering system used by the water purifier. Many models are rated depending on the number of liters of water it can handle before the filter needs to be changed. This detail is provided by all the manufacturers and you must check it before buying the water purifier.

2. For how long does an under sink water purifier last?

The lifespan of an under sink water purifier depends on how well are you maintaining it. If you are changing the filters regularly, the purifier can be used for years. If you are not changing the filters regularly, you will end up increasing the risk of a build-up of contaminants. This will eventually harm the water filtering system.

3. How does the Reverse Osmosis work in an under-sink water purifier?

The RO is common for any type of water filter. The Reverse Osmosis comes with a semi-permeable membrane that allows only pure water to pass. The membrane eliminates the contaminants that are too large to pass through the small pores. Thus, the purification process removes larger and harmful particles.

4. What to check when buying the under-sink water purifier?

The filtration efficiency as to how long you can use the water purifier in your area. You must also check the tap compatibility before installation.

5. Hardness and TDS of water are the same?

The hardness of water represents the amount of calcium and magnesium salts in water. The hard water lefts impurities in the tank down the below. The TDS is the mixture of total dissolved and undissolved salts of both organic and inorganic.


The under-sink water purifier is a new concept in the market. It has become more popular in small houses or nuclear families. The greatest advantage of the under-sink water purifier is that it saves a lot of space and does not require much maintenance like the regular water purifiers.

These types of filters are hygienic because they are under the sink, away from any oil and dust.

As per our recommendation, we would choose “Kent Excell water purifier”, because it has RO + UV/UF + TDS type of water filter and high-water storage capacity in less space. 

You can also go to the other two products as they are great at their place.

We hope this article helped you in choosing the best under sink water purifier that satisfies your requirements.