Review: Whirlpool WHER25 Reverse Osmosis Drinking Water Filter System

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In this review, we are going to take a thorough look at the Whirlpool WHER25 reverse osmosis water filter system.

Now, obviously most of us associate Whirlpool with all different kinds of home appliances, from top-load washers and dryers to refrigerators and microwaves. But how well does the company score when it comes to water treatment? We are about to find out!

Whirlpool WHER25

Whirlpool WHER25

Filter Stages:3
Gallons Per Day:18
NSF Standard:42, 58
Warranty:1 Year

Our Rating

Whirlpool WHER25 Reverse Osmosis System – Key Features

The WHER25 uses 4 (actually it’s only 3) stages of filtration tested and certified against NSF standards 42 and 58 to deliver bottled water quality right at your kitchen sink.

  • Stage 1: A sediment pre-filter reduces sand, dirt and other larger particles as well as an average of 95.2% chlorine taste and odor. This improves the looks, taste and smell of your water. And more importantly, it protects the system’s delicate RO membrane from clogging and thereby extends its working life, which in turn saves you money.
  • Stage 2: The semipermeable RO membrane separates water from dissolved solids and organic matter. Some reduction rates are: Lead (99.1%)*, arsenic(V) (98.2%)*, cysts (99.99%)*, nitrate plus nitrite (75.4%)*, chromium 6 (97.0%)*. *tested by NSF International
  • Stage 3: An activated carbon post-filter ensures that your water is fresh at all times by removing any remaining tastes and odors.

The recommended pressure at which this system can operate is 40-100 psi. If the water pressure in your home is too low, filtration might be inefficient and slow.


The WHER25 was designed to be easy to install and maintain without the need for a plumber and without having to struggle with ongoing leaks. The RO system comes with illustrated DIY instructions.

Usually, we would provide you with an installation video at this point, but unfortunately there is none.
Whirlpool WHER25

The Whirlpool WHER25 – learn more on

The Package (Parts)

  • RO module
  • 2x filters
  • RO membrane
  • Feed water adapter
  • Drain saddle
  • Water storage tank (white)
  • Tank connector
  • Coin battery
  • Faucet
  • Color-coded tubing
  • Nitrate/nitrite test kit
  • Eye dropper

Filter/Membrane Replacements

Like we said, this system was designed to allow for easy maintenance. You can change filters in seconds – literally. Just give them a quarter-turn, remove and replace. No need to turn off the water supply, no spilling, no leaks, no worries.

The built-in filter change indicator is supposed to let you know when filters need replacement. However, our guess is that the indicator measures time instead of actual TDS, so don’t put too much faith in it.

According to Whirlpool, this is how often you will have to change each component in order to keep up the filtration performance and guarantee high quality drinking water for your family:

  • Sediment pre-filter: About every 6 months
  • RO membrane: Every 2 years
  • Activated carbon post-filter: About every 6 months

As always, replacement frequencies are highly dependent on your water usage and source water quality. So you might have to change the filters less/more often.

Replacement costs? On the expensive side, especially when we take into account the fact that we only have 1 pre-filter, 1 post-filter and 1 RO membrane.


Here is a link to the product manual.

WHER25 Cons

Here is what we don’t like:

  • In the user manual it says that one has to open the RO faucet and let the water run for 24 hours to purge the system after each filter replacement. Although “water flow will be a slow trickle at this time“, to us this seems like a huge waste.
  • Customers have complained about missing parts that delayed the installation.
  • Others have mentioned system parts that started leaking all of a sudden.
  • The system’s filtration capacity is 18 gpd at max, which is a lot less than what we get with most other models.
  • Whirlpool’s customer service is not always helpful.
  • The filters and membrane tend to wear out faster than specified.

Whirlpool WHER25 Review: Our Verdict + Best for

On the one hand, the Whirlpool WHER25 is one of the few reasonably priced RO filter systems made in the USA. Water quality is good and, what’s more, maintenance requirements are low.

On the other hand, we have a low filtration capacity and filters that need to be flushed for a full day prior to use and tend to wear out fast. On top of that, installing this system is a bit like gambling – it may flood your kitchen cabinet.

Our verdict: 3.5 out of 5 stars!

In our opinion, the Whirlpool WHER25 is best for small families who insist on NSF-certified reverse osmosis water purification.

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In case you have any questions about the Whirlpool WHER25 or any other filter system really, please don’t hesitate to leave a comment below!

About the Author Alexandra Uta

Alex is a content writer with an affinity for research and a methodical attention to detail. Her writing interests have included many different topics, water treatment among them, which have encompassed varying writing styles.
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Leave a Comment:

Eric says March 29, 2019

I installed one of these 4 months ago and am totally pleased with the installation , had no leaks , and enjoy the taste of the water. and with the cost. im thrilled.

    Gene says March 29, 2019

    Hi Eric,
    That’s great to hear. Thank you for sharing!

Geoff says November 6, 2019

I’ve had one of these for several years and it’s been great. I would recommend it. Save on filter costs by not purchasing a post filter and simply rotate the post filter to the pre filter when you change them out. The water production is a little low at times, like in the morning when we all fill our water bottles and make coffee etc. But by planning ahead and filling some stuff the night before it’s not really an issue. One thing I did was pump up the bladder in the reservoir to increase the pressure and the water flow increased dramatically, and it seems like it never runs out of water now, which has me worried that I may have over pressurized it and damaged it somehow. I am now not sure if I’m getting filtration or not. I pumped it up a little bit several times and when the pressure decreased I pumped it again. Then the last time I decided to pump it a lot and may have overdone it. I’m looking into buying a new unit because I think I may have broke this one, and I think I’ll buy the same unit. I need to check whirlpool tech support first though.

    Gene says November 6, 2019

    Hey Geoff,
    Thanks for sharing your experience. You can use a pressure gauge to check the pressure inside the tank when empty. It should read somewhere around 6-8 psi.
    The issue with overpressurizing is that it also causes more backpressure on the system which increases the amount of wastewater going down the drain.

Holly Benton says December 23, 2020

I installed my WHER25 system in Jan. 2009. I replace 1&3 filters regularly, and #2 membrane filter every 2 years. My system still does great, after nearly 12 years. Will buy again.

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