Top 10 Best Undersink Water Filtration Replacement Parts in 2025 - #1 Top Picks Today

10 Best Undersink Water Filtration Replacement Parts of 2025

Find 10 best undersink water filtration replacement parts available on the market today. Join the millions of savvy shoppers who trust Greatest.Guide daily for reliable recommendations.

Updated April 14, 2025

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Captain O-Ring - Replacement 151122 O-Rings Compatible with Pentair Pentek Big Blue Water Filters OEM Size ORing Buna-N (3 Pack)

Replacement 151122 o-rings compatible with Pentair/Pentek style Big Blue Water Filter Housings (3 Pack)

Includes 3 replacement o-rings (also called seals or gaskets) to repair your leaking water filter housing [OEM UPC: 051678511220 , 885343762095]

151122 OEM Size o-rings are approximately 5.5" Inside Diameter x 5.83" Outside Diameter x 0.165" Thickness. Please confirm that you need this size o-ring and that your filter housing is listed on the list of compatible housings or that your product manual calls for the 151122 o-ring part number or one of the other part numbers listed below.

Direct Replacement for the following part numbers (see description below for full water filter compatibility list): Ace Hardware 4001756; American Plumber 152032, W10-OR; APEC O-RING-HB; Ametek Kleen-Plus 151122-03; Culligan OR-100, 151122-27, 01019189; HomeMaster #Oring122; Pentek 151122, BB BUNA-N

Molded from NSF 61 certified buna-n rubber for safe and clean drinking water. Manufactured and warrantied by Captain O-Ring LLC. Proudly assembled in the USA!

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APEC WATER

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APEC Water Systems Replacement Feed Water Adapter & Drain Saddle Valve For Undersink System (MOVEKIT)

APEC Water Systems Drain Saddle Valve used with reverse osmosis (RO) systems Fits standard 1-1/4" to 1-1/2" diameter pipes

APEC Water Systems Feed Water Adapter used with reverse osmosis (RO) systems Fits standard 1/2" or 3/8" faucet pipes

Moving Kit Consists of saddle valve, drain valve & tube plug

Manufactured using certified materials

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APEC WATER

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APEC Water Systems 1/4" Quick Connect Check Valve Replacement Part (CHECK-VAL)

Check valve replacement part for APEC RO-90, RO-PH90, RO-PERM, RO-PUMP, ROES-50, ROES-75, ROES-PH75, ROES-PHUV75, ROES-UV75 and ROES-UV75-SS

Featured 1/4 inch quick connect

Fits all under counter water filter systems

Manufactured using certified materials

Light weight,easy to Install and unload

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Waterdrop

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Waterdrop 10UA Under Sink Water Filter System, Reduces PFAS, PFOA/PFOS, Lead, Chlorine, Bad Taste & Odor, Under Counter Water Filter Direct Connect to Kitchen Faucet, NSF/ANSI 42 Certified, 8K Gallons

Less than ＄25.99 per replacement filter (Search " B085G66JTZ "on Amazon), save over 50% of cost on subsequent use.

[After Sales Assistance] Waterdrop Backs the WD-10UA's high-end technical performance with a comprehensive prorated performance service; should a quality issue arise with the filter, you can contact us.

[Deep Filtration and IAPMO Certified] Based on independent testing, this filter can efficiently reduces PFAS, PFOA/PFOS, large-particle contaminants such as rust, lead, chlorine, heavy metals, chemical impurities, and sand through thorough purification for clean drinking water. The filter is made of high BPA-free and lead-free materials. It also can successfully reduce chlorine, taste, and odor. This filter is certified by IAPMO against NSF/ANSI 372 Standard and NSF/ANSI 42 Standard. It can lower lead when tested by a third-party laboratory against NSF/ANSI 53 standards. Please use the "WD-10UA" search term to review the 42&372 certification on the IAPMO website.

[Innovative Design] Only a cold-water source should be used to power the filter. Its twist-and-lock construction and push-to-connect fittings enable installation in three minutes, three second replacement, and safety-assuring integration. This filter comes with a 3/8" line that connects directly to US sinks' standard 3/8" feed water valves. The system is connected to 1/2" and 3/8" cold water pipes and faucets with the use of the 3/8"-1/2" convertor fitting.

[Solve Clogging Problem] By upgrading the filtration area, our filter now provides a 20X increase in dirt adhesion area, enhancing filtration capability while minimizing the risk of clogging.

[Filter Replacement and Long Lifespan] This filter system may be upgraded with a UF filter or a MZ filter to meet your water needs. It is compatible with several filters with various functions. Each filter system has a maximum service life of 12 months or 8k gallons when used with municipal water, which is sufficient to cover the needs of an entire household. Before going on vacation, please Put the filters in separate sealed plastic bags, and store the bags in your refrigerator (NOT the freezer) to keep it fresh in 30 days.

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iSpring

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iSpring AFW43 Water Systems Feed Water Adapter, Fits 1/2" NPT and 3/8" COMP, Cold Water Supply Valve

Durable and easy to install - Push-in quick connect fittings offer easy DIY installation with no tools required

Fits Both 1/2" NPT and 3/8" Comp Cold Water Supply Valve

Suitable for most RO systems in the market

Ceramic valve disk for up to 1 million leak-free smooth turns

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Mattox 1/4" Quick Connect Water Purifiers Tube Fittings for RO Water Reverse Osmosis System - Pack of 12 (Ball Valve+Y+L+I+T Type) + 5 Meters (16 feet) Tubing - Polyethylene Plastic - White

Size: 1/4 inch ,Material: Polyethylene Plastic

Easy to use,Mini quick connect push tee 1/4-Inch OD

Push fit fittings, fit all water filter systems and RO system

Prolong the service life of RO membrane,Flexible, easy to cut

Designed for use with the Stealth Reverse Osmosis Systems,ice maker

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APEC WATER

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APEC Water Systems Replacement ORing for ROES-50 3.5" OD Reverse Osmosis Water Filter Housings, O-Ring (3 pcs O-Ring-Set-B)

IMPORTANT: A set of 3 O-rings for standard filter housings of APEC RO systems. Please kindly check the second gallery image for compatibility of this O-Ring set

Diameter 3.5 inch OD

Light weight, easy install and unload

Manufactured using NSF-compliant materials

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iSpring

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iSpring ICEK Ultra Safe Fridge Water Line Connection and Ice Maker Installation Kit for Reverse Osmosis RO Systems & Water Filters, 1/4", 20 feet

Connects any water filtration system (including reverse osmosis systems) to the ice maker or water dispenser of your fridge

Delivers crystal clear ice cubes and great tasting RO water to your fridge, superior to inline fridge filters

Kit includes everything you need for the installation - 20 feet 1/4" tubing, a 1/4" x 1/4" x 1/4" "T" fitting, an inline 1/4" x 1/4" shut off valve, and a compression fitting set. Tested by independent third-party to meet NSF/ANSI Standards

Durable and easy to install - Push-in quick connect fittings offer easy DIY installation with no tools required

Push-in quick connect fittings offer easy DIY installation with no tools required

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APEC WATER

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APEC Water Systems Feed Water Adapter 1/2" & 3/8" for Undersink System (SADDLE-FEED-1238)

Used with reverse osmosis (RO) systems

Fits standard 1/2" or 3/8" faucet pipes

Includes a 1/4" outlet needle valve to feed water to RO systems or water filter systems.

Manufactured using certified materials

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Waterdrop

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Waterdrop 15UA Under Sink Water Filter System, Reduces Lead, Chlorine, Bad Taste & Odor, Under Counter Water Filter Direct Connect to Kitchen Faucet, NSF/ANSI 42 Certified, 16000 Gallons, USA Tech

Ultra-long service life: When used with municipal water, each filter has a maximum service life of 24 months or 16,000 gallons.[1]

Compatibility: Our system perfectly fits the feed water adapter no matter with 3/8" or 1/2" connector. If a female threaded connector is needed to connect to your faucet, please send us a message. Our professional technical team will provide you with customized and systematic solutions.

Innovative multistage filtration: The Waterdrop Direct Connect Undersink Water Filtration System uses innovative multistage filtration. And it can effectively reduces chlorine, heavy metals, chemical iṁpurity, sediment and other large particles.[2] Enjoy healthy and pure water straight from your tap no need to buy bottled water anymore!

IAPMO certified filter: Made from premium BPA-free and lead-free materials, the under sink water filter is certified by IAPMO against NSF/ANSI 372 Standard, ensuring reliable use from inside to outside. Certified by IAPMO against NSF/ANSI 42 Standard, the water filter can effectively reduce chlorine, taste and odor. Tested by third party laboratory against NSF/ANSI 53 standard it can reduce lead. To look over the 42&372 certification, please search "WD-15UA" on IAPMO official website.

Easy installation: The under sink water filter system should be connected only to a cold water supply. With innovative push-to-connect fittings, the entire installation process takes less than 3 minutes. The system includes a 3/8 inchhose with a direct connection that adapts to standard 3/8 inch feed water valves under US sinks. The 3/8 inch 1/2 inch convertor fitting helps you connect the system to both 1/2 inch and 3/8 inch cold water lines and faucets.

Fast flow rate & multiple uses: The fast and stable water supply provides pure and fresh water that tastes like spring water. The tested full flow rate is 0.75 gpm at 60 psi. Developed for household and commercial use, the Undersink Water Filtration System can be installed in your kitchen, bathroom, RV, or office to meet your daily water needs. Ideal for drinking, cooking, skincare, and cleaning.

Disclaimer: While we strive for accuracy, we cannot guarantee that all product features listed are complete or error-free. Please confirm the details with the retailer before making a purchase.

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O-Ring 151122 Compatible with Pentair Big Blue Water Filter Housings Seals Gaskets (6/Pack)

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AXEON 150 GPD Membrane and Flow Restrictor - Undersink Water Filtration System Replacement Part - 1 Count

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Waterdrop 3US-MAX-F01 Maximum Under Sink Water Filter, Replacement for Filtrete® 3US-PF01, 3US-PS01, 3US-MAX-S01, Aqua-Pure C-Cyst-FF, Manitowoc K-00337, K-00338, NSF/ANSI 42 Certified, Pack of 2

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Our #1 Pick

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Captain O-Ring - Replacement 151122 O-Rings Compatible with Pentair Pentek Big Blue Water Filters OEM Size ORing Buna-N (3 Pack)

Replacement 151122 o-rings compatible with Pentair/Pentek style Big Blue Water Filter Housings (3 Pack)

Includes 3 replacement o-rings (also called seals or gaskets) to repair your leaking water filter housing [OEM UPC: 051678511220 , 885343762095]

151122 OEM Size o-rings are approximately 5.5" Inside Diameter x 5.83" Outside Diameter x 0.165" Thickness. Please confirm that you need this size o-ring and that your filter housing is listed on the list of compatible housings or that your product manual calls for the 151122 o-ring part number or one of the other part numbers listed below.

Direct Replacement for the following part numbers (see description below for full water filter compatibility list): Ace Hardware 4001756; American Plumber 152032, W10-OR; APEC O-RING-HB; Ametek Kleen-Plus 151122-03; Culligan OR-100, 151122-27, 01019189; HomeMaster #Oring122; Pentek 151122, BB BUNA-N

Molded from NSF 61 certified buna-n rubber for safe and clean drinking water. Manufactured and warrantied by Captain O-Ring LLC. Proudly assembled in the USA!

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