# Why are appliance water filters so expensive?

**URL:** <https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290>\
**Category:** Factual Questions\
**Created:** [September 22, 2026, 8:22pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290 "2026-09-22T20:22:47Z")\
**Posts on this page:** 20\
**Page:** 1

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**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\
**Post date:** [September 22, 2026, 8:22pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/1 "2026-09-22T20:22:47Z")

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I have a hot water dispenser for my kitchen sink that needs to be replaced (dispenses 200°F water on demand). The Insinkerator brand offers a water filter “system” for over $120. The system is just a cap with the hose fittings, and you screw the filter cartridge into the cap. Replacement filters are ~$50.

WTF? The filter will extend the life of the tank (I’ve gone through two of them). But it doesn’t seem like it should be so expensive.

Filters for my refrigerator are similarly expensive. It’s just a filter smaller than a can of tennis balls.

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**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\
**Post date:** [September 22, 2026, 8:29pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/2 "2026-09-22T20:29:32Z")

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Because they can?

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**Author:** ![Johnny\_Bravo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_bravo/32/493_2.png) [@Johnny\_Bravo](https://boards.straightdope.com/u/Johnny_Bravo)\
**Post date:** [September 22, 2026, 9:16pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/3 "2026-09-22T21:16:02Z")

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Same business model as printers: lock you into an ecosystem and then gut you on refills.

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**Author:** ![ThelmaLou](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thelmalou/32/390_2.png) [@ThelmaLou](https://boards.straightdope.com/u/ThelmaLou)\
**Post date:** [September 22, 2026, 10:15pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/4 "2026-09-22T22:15:26Z")

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Likewise, glucometers are cheap, diabetes test strips are relatively expensive.

That’s how they make money.

* * *

Because of the reference to _tennis balls,_ this thread has a tag of “tennis.”  
🤔

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**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\
**Post date:** [September 22, 2026, 10:19pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/5 "2026-09-22T22:19:14Z")

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I think King Gillette invented the approach; sell the razors cheap but charge dearly for the proprietary replacement blades. If possible, switch to a whole-house water filter that uses generic filter cartridges.

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**Author:** ![We\_re\_wolves\_not\_werewolves](https://avatars.discourse-cdn.com/v4/letter/w/838e76/32.png) [@We\_re\_wolves\_not\_werewolves](https://boards.straightdope.com/u/We_re_wolves_not_werewolves)\
**Post date:** [September 22, 2026, 10:27pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/6 "2026-09-22T22:27:48Z")

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yep, for all the reasons stated above. And, many of the designs are patented, preventing competition from low cost generics. see, just by way of example, [US8137551B1 - Push filter with floating key lock - Google Patents](https://patents.google.com/patent/US8137551B1/en?oq=8%2C137%2C551)

which has been the subject of various patent infringement cases against various generic filter manufacturers.

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**Author:** ![XOldiesJock](https://avatars.discourse-cdn.com/v4/letter/x/ec9cab/32.png) [@XOldiesJock](https://boards.straightdope.com/u/XOldiesJock)\
**Post date:** [September 22, 2026, 11:05pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/7 "2026-09-22T23:05:20Z")

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We have a 15 year old Whirlpool refrigerator that insists we replace the water filter every six months…or maybe something terrible will happen? I don’t know. The filters have gone up in price over the years and now cost around $60. I have now spent more on those filters than the cost of the refrigerator itself.

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**Author:** ![WolfpackJeep](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpackjeep/32/2921_2.png) [@WolfpackJeep](https://boards.straightdope.com/u/WolfpackJeep)\
**Post date:** [September 22, 2026, 11:11pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/8 "2026-09-22T23:11:58Z")

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I have a Kenmore fridge that is still chugging along, so I replace the filter whenever the light turns red. (I failed to do this once, and I’ve always blamed that for an ice plug that formed in one of the lines in the freezer.) I have given up on buying Kenmore-branded filters; the last few I bought leaked horribly. I’ve had decent luck with aftermarket filters on Amazon; don’t buy the cheapest thing, and read the reviews.

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**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\
**Post date:** [September 23, 2026, 12:08am UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/9 "2026-09-23T00:08:57Z")

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Can’t you just ignore the filter, particularly if you don’t connect the water supply line?

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**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\
**Post date:** [September 23, 2026, 2:17am UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/10 "2026-09-23T02:17:22Z")

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Well, in OP’s cae, it’s a water boiler, so not connecting the water line is not very helpful.

But a refrigerator filter is not needed if the fridge isn’t connected to a water line (or doesn’t have an icemaker and/or water dispenser to connect). But obviously, some people value having those amenities even if the filters add to the cost, and “just don’t do that” isn’t a very insightful contribution.

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**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\
**Post date:** [September 23, 2026, 9:47am UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/11 "2026-09-23T09:47:16Z")

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> [@Dewey\_Finn](#):
>
> I think King Gillette invented the approach; sell the razors cheap but charge dearly for the proprietary replacement blades.

And then printers, with printer ink/cartridges.

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**Author:** ![ZonexandScout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zonexandscout/32/544_2.png) [@ZonexandScout](https://boards.straightdope.com/u/ZonexandScout)\
**Post date:** [September 23, 2026, 12:45pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/12 "2026-09-23T12:45:13Z")

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I have an older Brondell under-the-sink water filter that uses a single cartridge that costs about $50. My wife and I like it a lot, but the cartridges do begin to “slow down” after about 8 months. Due to some recent kitchen repairs, I figured we should just go ahead and replace the entire unit. We found that we could get a three-cartridge unit that should extend the life of the cartridges to more like two years. (It has two stages of pre-filter.) The cost of a set of three replacement cartridges is $75, even though one of the cartridges (the final one) is the exact same cartridge used in our previous single cartridge system. Go figure.

“Whole house” filters (string, paper, or activated charcoal) are much less expensive per unit and have much better flow capacity. They use larger, sturdier filter holders with less robust filter inserts. If I could fit a couple under my kitchen sink (string and then charcoal), I would probably go that direction instead.

Having a water filter that is completely sealed and has the special valve and seal so it can just insert and twist is obviously a major factor in the high cost of some filters.

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**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\
**Post date:** [September 23, 2026, 3:14pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/13 "2026-09-23T15:14:08Z")

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When getting anything that has consumables like this, I make sure it’s a reputable brand that will likely be around in the future and preferably even has some off-brand part support (with no features that detect if you’re using the cheaper version). There are few reputable refrigerator brands today, Samsung is especially bad and saw the news this morning that a firmware update bricked their fridges.

Printers are often cheaper than the replacement cartridges, but note that buying a new printer is not an economic hack, they come with underfilled cartridges. Brother is the best brand especially for basic black and white laser jets. Epson EcoTank if you need color. I’ve used enough HPs at work to know better than to get one for personal use.

I have not investigated house water filters, fridge (POS Samsung that came with house and is limping along) just gets municipal water which is good enough, we have a Brita pitcher for regular consumption.

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**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\
**Post date:** [September 23, 2026, 3:26pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/14 "2026-09-23T15:26:43Z")

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> [@ThelmaLou](#):
>
> Likewise, glucometers are cheap, diabetes test strips are relatively expensive.

I have seen advertisements to buy your unused test strips.

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**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\
**Post date:** [September 23, 2026, 7:45pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/15 "2026-09-23T19:45:00Z")

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> [@thelurkinghorror](#):
>
> Printers are often cheaper than the replacement cartridges,

I think you meant to write “Inkjet printers are often …”

If you buy a laser printer, none of those problems obtain.

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**Author:** ![crazyjoe](https://avatars.discourse-cdn.com/v4/letter/c/f14d63/32.png) [@crazyjoe](https://boards.straightdope.com/u/crazyjoe)\
**Post date:** [September 23, 2026, 9:06pm UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/16 "2026-09-23T21:06:49Z")

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I have a fridge with similarly expensive filters. Instead of replacing the cartridges, I buy inline filters (linked below), that use “push to connect” fittings. If your ice/water line is plastic – as most newer ones are these days – it is super simple to turn off the supply, cut it in the middle somewhere and then push the supply end into this filter. Then turn the water on and flush 3 or 4 gallons into a 5-gallon bucket to get the loose carbon dust out (you can use this water to water your plants with, but it will not taste good if you drink it). Then turn the water off and hook the other end into the loose end of your water connection. It lasts for 10k gallons or a year (after a year, even if you didn’t use 10k gallons, the water starts to taste a little funny) and costs \< $20. I write the date I installed it on the filter so I remember when to change it, and also put a reminder in my phone. I suspect you could do something very similar for your hot water dispenser. In fact, I have a similar unit I bought for my upstairs sink for $36 (replacement filter cartidges are \< $20, this kit came with hoses).

[Amazon.com: GE GXRTDR Exterior Refrigerator/Icemaker Filtration System, White : Appliances](https://www.amazon.com/GE-GXRTDR-Exterior-Refrigerator-Filtration/dp/B002OIEOCG/ref=sr_1_4_pp?crid=11ON7YGH02L86&dib=eyJ2IjoiMSJ9.0rDI9utxfGxQGDG6cIJA5DUBhAZstd1ayiyP3ZtcidU9jwau6NHkW406915wrVzkPzHg_qclqSS7s9U9X5mdJSVgi0vIeBlKQssKd_mfF-sodTSceS6lrYTgEQNlRvdIP3mCo24dnpVoUObykgt-HhndmXMLV2PTbYbFl10biGclX1DF8RYEiJBoaJNr1hDL7gveH8hdYsziCqTxmfmnaCjHsD1bxcJbIuqoKhVkaIY.yDA7ghe1hIC1OE8VTzlQ7YDsrP4fn1rRcCbnzNLhkes&dib_tag=se&keywords=inline%2Bwater%2Bfilter%2Bfor%2Bfridge&qid=1790197196&sprefix=inline%2Bwater%2Bfilter%2Bfor%2Bfridge%2Caps%2C176&sr=8-4&th=1)

[AQUA CREST 5KDC Under Sink Water Filter System | Reduces PFAS, PFOA/PFOS, Chlorine, Direct Connect Under Sink Water Filter, NSF/ANSI Tested, 5K Gallons Ultra High Capacity - Amazon.com](https://www.amazon.com/dp/B089D156HL?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_3&th=1)

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**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\
**Post date:** [September 24, 2026, 12:47am UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/17 "2026-09-24T00:47:10Z")

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Sadly, this is no longer true.

HP is charging upwards of $400 for new toner on their color lasers. The one I have (Laserjet 451DN) will still take aftermarket toners, which is the only way I can afford to run it. The 3rd-party toners are around 1/10 the price of HP.

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**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\
**Post date:** [September 24, 2026, 1:16am UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/18 "2026-09-24T01:16:55Z")

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Ah hah! The operative word in your problem is “HP” rather than “inkjet” or “laser”.

I have one of these; I paid $499 ~2 years ago; it’s ~15% higher due to stupidity now:

> **[Amazon.com: Brother MFC-L3780CDW Wireless Digital Color All-in-One Printer | 31...](https://www.amazon.com/Brother-MFC-L3780CDW-Wireless-Subscription-Replenishment/dp/B0CFCW8PGV)**
>
> The Brother MFC-L3780CDW wireless laser printer all-in-one is designed for small business leaders and home office users, combining copy, scan, and fax functionalities into a single device. This laser printer scanner copier all-in-one consistently...

A set of four genuine Brother cartridges is here:

> **[Amazon.com: Brother Genuine TN2294PK Standard Yield 4-Pack Printer Toner...](https://www.amazon.com/Brother-Genuine-Standard-Cartridge-TN229/dp/B0BNQFCPZY)**
>
> Print confidently up to 1500 pages black and 1200 pages color (Cyan, Magenta, and Yellow)(1) with Brother Genuine TN2294PK Standard Yield Toner Cartridges. Brother Genuine toner is the only replacement toner brand engineered by Brother for Brother...

Various no-name cartridge sets of 4 start at $59 & go up to ~$200. These folks claim 2000+ pages:

> **[Amazon.com: TN229XL MFC-L3780CDW Toner Cartridges 4 Pack for Brother...](https://www.amazon.com/TN229XL-MFC-L3780CDW-Cartridges-Brother-MFC-L3720CDW/dp/B0H8SLPLDK)**
>
> Amazon.com: TN229XL MFC-L3780CDW Toner Cartridges 4 Pack for Brother MFC-L3720CDW | TN-229XL TN229 XL Compatible for HL-L3280CDW HL-L3220CDW MFC-L3720CDW MFC-L3765CDW HL-L3295CDW MFC-L3780CDW Printer(BK/Y/C/M) : Office Products

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**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\
**Post date:** [September 24, 2026, 2:27am UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/19 "2026-09-24T02:27:28Z")

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> [@LSLGuy](#):
>
> I think you meant to write “Inkjetprinters are often …”
> 
> If you buy a laser printer, none of those problems obtain.

No, its lasers too. [For example Wirecutter mentions it here](https://www.nytimes.com/wirecutter/reviews/best-laser-printer/).

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**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\
**Post date:** [September 24, 2026, 2:54am UTC](https://boards.straightdope.com/t/why-are-appliance-water-filters-so-expensive/1033290/20 "2026-09-24T02:54:12Z")

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> [@XOldiesJock](#):
>
> insists we replace the water filter every six months…or maybe something terrible will happen?

Well at some point it quits being effective at filtering because the activated charcoal is spent and has retained all the stuff it’s going to retain. But also my understanding is they could harbor bacteria or mold at that point since it also removes the chlorine which helps prevent that. I am a little light on facts there.

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