Watts Premier 4-Stage Undersink Reverse Osmosis System Review

When you are looking for a water filter system, there are many to choose from. However, Watts Premier 4-Stage Reverse Osmosis System is a great value for money choice. This article will review what this product has to offer and help you make an informed decision on whether or not it is right for you.

If you are looking for an under-sink water filter you know your tap water is full of added nasty chemicals and is still not always clean enough or even really safe to drink. Or you may have not thought about the health effects, you just want to get rid of the horrible taste that your tap water has.

Watts Premier 4-Stage Undersink Reverse Osmosis System Review

Your water travels a very long way before reaching your faucet, from source to tap it could be only a few miles but it could be hundreds of miles. It could have been sitting in holding reservoirs for a long time, absorbing metals and other contaminants. You simply have no idea where your home water supply has been before reaching you.

All the smell and taste come from contaminants and chemicals in the pipelines that are picked up in the race to reach your home. These contaminants cause odor and an unpleasant taste in your water. The Watts premier 4 stages reverse osmosis system safely and quickly removes all these contaminations from your water, 


Watts Premier 4-Stage Undersink

1. Watts Premier 4-Stage Undersink

Includes a RO Pure Reverse Osmosis module with pre-installed filters, parts bag, chrome, monitored, top mount, air-gap faucet, and 3 gallon storage tank.

  • This Reverse Osmosis system consists of 4-stages of filtration to provide you with high quality, great-tasting drinking water
  • Shut off valves in each filter head shuts off the water flow when cartridges are removed.
  • Check valves installed in the filter lid between cartridges prevent back-flow.

Four stages of filtration trap sediment and other particles to provide clean drinking water. Watts premier 4 stages reverse osmosis system is one of the best and affordable under sink systems that produces safer and healthier water. It is capable of removing 99% of contaminants from your Tap water.

If you truly care about the health of your family then you need to ensure they have access to clean, pure drinking water. The purification process of this premier water system will remove bacteria and viruses, guaranteed.

Interested to know more? then you can read on, if you don’t care about the specifics and just want a great value water filter then go get yourself a Watts Premier 4 Stage Filter unit and start enjoying clean great tasting water. 

Let’s Dive into the nitty-gritty details of the Watts Premier 4 Stage filter.

Features of Watts Premier 4-Stage Reverse Osmosis System


The efficiency of the system is determined by the water waste ratio.

Water waste is an unavoidable part of the reverse osmosis filtration process. You can’t expect purified water from a Reverse osmosis system without some wastage. Although, the ratio of water waste varies from system to system. It also depends on the feed water pressure & temperature.


For the Watts premier 4-stage RO-system, we don’t have any authorized water waste ratio from the manufacturer. But the tests have shown that this system waste between 3-4 gallons for every gallon of purified water produced.

Water Production

Water Production may change due to the feed water pressure and water temperature. But, at the standard pressure and temperature, it is capable of producing 50 gallons per day.

Which makes it an ideal under-sink water filter for small and medium-sized families.

This water production may not be enough for larger-sized families.

You can check out the APEC RO-90 filter which is the best water filter for larger families.

With a water pressure of 40 psi it works effectively, if the pressure is below 40 psi it can reduce the performance of your under-sink RO system.

Thankfully 40psi is the standard pressure that most households have.  So, you don’t have to take too much notice of this.

Best On Budget

Flow Doctor Water Pressure Gauge Kit

Flow Doctor Water Pressure Gauge Kit

All Purpose, 6 Parts Kit, 0 to 200 Psi, 0 to 14 Bars

If you want to confirm that you have enough water pressure, you can check the water pressure at your home using this Simple water pressure gaugeFlow%20Doctor%20Water%20Pressure%20Gauge%20Kit,%20All%20Purpose,%206%20Parts%20Kit,%200%20to%20200%20Psi,%200%20to%2014%20Bars,%20Standard%203/4%22%20Female%20Garden%20Hose%20Thread%20Plus%205%20Adapters%20to%20Test%20in%20Multiple%20Locations%20Indoors%20and%20Outdoors“> or you can use the bucket test method, but this is not as accurate. 

Filtration Process

Watts premier has the 4-stages of the filtration process. It removes 99.9% of contaminants from the feed water.

All 4 stages of the process have their own task to do.

Check what each stage of the filter does below:

Filtration Process

Stage 1: This stage ensures that the water is free from rust & dust. In short, this stage has the job of removing all the sediments and particles from water that has an impact on the color and taste of the water.

Stage 2: There are many particles that cause an unpleasant odor in your water and affect the taste of water making it less desirable, and in some cases, undrinkable. Stage 2 works to remove all these particles from water.

“Filters at stages 1 and 2 are known as pre-filters. Their performance has a direct impact on how effective the stage 3 filter RO-Membrane filter is.”

Stage 3: At this stage, the reverse osmosis membrane gets into action. It removes up to 99% of all possible harmful contaminants and TDS from the water. The contaminants include arsenic, viruses, fluoride, cadmium, bacteria & many more. A vast reduction in nitrites and nitrates also occurs during this stage.

“The filters that work after an RO-Membrane are called Post filters. They give final touches to water treatment

Stage 4: This stage ensures that you are drinking completely pure water. When you turn on the faucet, this stage of the process eliminates all the remaining microscopic particles and contaminants that previous stages may have not been able to filter out. 


We have reviewed only convenient, trustworthy, durable, and top-performing RO systems. There are many Osmosis water filters that are really difficult to install, causing nothing but frustration and headaches, when all you want is simple filtered water from your tap. 

 But it is not the case with Watts Premier RO pure system, because the mounting, and installation of this filtration system is so simple and straightforward. You won’t need an engineering degree or plumbers qualification, you definitely will not be needing to pay for a professional to assist with the installation of the Watts Premier Filter. 


Instructions Manual

If you are new to the reverse osmosis system you can use the Instructions manual that comes along with the system. The instructions Manual is Concise, easy to understand, and well-written.

Before starting the process you should spend a little time reading the instructions manual, to ensure you do not make an error and damage the system.

Faucet Installation

The faucet installation is the only step in your installation process that may take a little bit more effort. The faucet needs to be installed in your kitchen sink before having purified water. The faucet installation requires a hole of 1 ¼” diameter in your sink.

Your installation process might be more effortless if your sink already has a hole. Otherwise, you have to drill the hole to set up the faucet. Drilling the hole is not that difficult, but it is the one part of the installation that intimidates some people and can make the process a little longer for those who are not used to working with power tools.

Filter Replacement

Watts premier Filter replacement is essential for keeping the performance at the maximum level. If you have done the installation of the system by yourself, then the filter replacement will not be an issue for you.

Filter Replacement Process
The filter Replacement of this Under sink water system is a piece of cake.

Let’s have a quick look at the filter replacement process

  • Lift-filter, Press button
  • Pull filter down
  • Remove Cap from the new filter
  • Push in the new filter

One really cool feature of this under sink osmosis system is an LED light that indicates the time when filters need to be replaced. TDS meter is also an important tool to check when filter replacement is required.

The Standard lifespan reported by the manufacturer is below. Although, the lifespan of filters also gets affected by the quality of feed water, and the frequency of use.

  • Filter 1 & 2 has to be replaced after 6 months
  • Filter 3 has a duration of 2-5 years
  • Filter 4 has to be replaced after 1 year

What Else We Love About the Watts RO System?


From the many RO systems we have previously reviewed, it is one of the more affordable systems available. Both in terms of the initial purchase cost and the ongoing filter maintenance cost, this system rates as a very reasonably affordable unit. The cost of the system is well below what you would expect to pay for a filter with all the features that the Watts premier 4 stages reverse osmosis system has.

High-Quality Components

The quality of components keeps the cost of maintenance and filters down. All the components are certified, which ensures that you will not be constantly changing filters and fixing leakages or worse fixing damages caused by leakages.

Shut Off Valve

Watts Premier RO pure 4-stage system has a shut-off valve to avoid water wastage. It automatically stops the water flow when the storage tank is full. You don’t have to monitor the water flow or storage tank.


This system has a 3 Year limited warranty. The manufacturers stand behind the quality and durability of the unit. You can consider it the best risk-free investment in your kitchen & health.

Better Than Bottled Water

You will have a compact & highly effective water filtration plant right in your kitchen. You don’t have to keep buying expensive bottled water after you get this system. Watts premier reduces the use of bottled water from many customers’ homes.

Satisfied Customers

Over 500 happy customers can’t be wrong, confirming that the performance of this system is one of the best options on the market, you can read the reviews yourself here on Amazon. There are a few reviews that are from people who clearly did not take the time to read the instructions. But typically these issues can be solved within no time after doing some research. 

One complaint that a few customers are having is it makes a small amount of noise while the filtration process is in operation.

Personally, a little bit of noise after using the water filter isn’t going to be a deal breaker for me, but you can make your own mind up. 


  • Taste better than Bottled water
  • Premium Quality Components
  • Ease of Installation
  • Quick and relatively simple filter replacement
  • Does not consume much electricity
  • 3 years limited warranty
  • Affordable filters


  • Faucet installation not so simple for some
  • Makes a very small amount of noise during operation

Final Thoughts

This under-sink reverse osmosis system ensures that you will have good value for your money. Watts premier does not have some of the advanced stages of filtration found in more expensive RO filters, and that’s why it might not be suitable for those who have well-sourced water.

However, it has all the essential features it needs to ensure you get great quality filtered water at home for your family. It is definitely a great system, capable of producing fresh-tasting, purified water for you. The system is more suitable for medium and small-sized families connected to mains municipal water and reasonable water pressure. 

The cost of this RO water system won’t make a big dent in your hip pocket. It will pay for itself in no time at all if you consider there will be no need to buy any more bottled water after having this system installed. 

It is recommended due to its affordability, design, high-quality components, and efficiency.

Similar Products

It’s not mandatory to have a large number of filtration stages to purify the water completely. There are many 4 Stages reverse osmosis systems that are also available that are really worth considering.

Like watts premier, Brondell H2O+ Circle and APEC RO-CTOP Reverse osmosis systems are also worth considering as they also are very good at removing contaminants effectively from the water to produce purified fresh-tasting water.

Have you found this review useful? 

Your friends and family might be interested too. Share to let them know more about this RO water filtration system.

Similar Posts