Which Water Filter Fits My Frigidaire Refrigerator? (PureSource Lines)

The right Frigidaire refrigerator water filter depends on which PureSource generation your fridge was built for – and the generations do not interchange. A WF3CB will not seat in a fridge designed for an ULTRAWF, and an ULTRAWF will not seat in one built for EPTWFU01. Before you buy anything, do the one thing that settles it: read the model number printed on the filter you are pulling out, or look it up in your owner’s manual. One fridge line uses different filters across model years, so the brand on the door is never enough.

This guide maps the five filters Frigidaire and its parent company Electrolux have shipped, explains why they are not cross-compatible, and tells you how to verify a filter’s NSF claims before you trust them.

The Short Answer: Match the Generation, Not the Brand

Frigidaire’s PureSource program has run through several distinct cartridge generations. Each one has a different body shape, port, and seating mechanism, so a fridge accepts exactly one of them:

• PureSource 2 – WF2CB: An older front-loading cartridge for side-by-side models, typically grille-mounted at the base.
• PureSource 3 – WF3CB: A roughly 9-inch twist-in cartridge, common on side-by-side and some French-door units built across the late 2000s and 2010s.
• PureSource Ultra – ULTRAWF: A push-and-click cartridge used in many Gallery and Professional French-door models.
• PureSource Ultra II – EPTWFU01 (also sold as Electrolux EWF02): The successor to the Ultra, used on French-door and side-by-side units produced after roughly 2015.
• PWF-1: A pitcher-style / standalone PureSource filter that appears in some configurations and is sometimes listed alongside the in-fridge cartridges; it is not a drop-in for the cartridge slots above.

The names look like a tidy sequence, but the hardware is not. PureSource 2, 3, Ultra, and Ultra II are physically different parts. You cannot reason your way from “I have a Frigidaire” to a single SKU. You confirm it.

How to Identify Your Exact Frigidaire Filter

There are three reliable ways to nail down your filter, in order of confidence.

1. Read the old filter. The fastest method. Pull the cartridge you have now and read the molded text. Genuine PureSource filters print the model – WF3CB, ULTRAWF, EPTWFU01 – directly on the housing. If an aftermarket filter is installed, it usually prints the Frigidaire number it replaces.

2. Look up your refrigerator’s model number. Find the appliance model tag, usually on the inside wall of the fresh-food compartment, along the top edge, or on the side near the crisper. Match that model number against Frigidaire’s accessory listing. Note the model tag often carries trailing revision digits (for example, a French-door model code may end in RF0 through RF9); those revisions can share a filter, but confirm rather than assume.

3. Note the slot mechanism as a tiebreaker. A push-and-click round cartridge inside the fresh-food compartment points to ULTRAWF or EPTWFU01. A twist-in cartridge points to WF3CB. A front-loading cartridge behind the bottom grille points to PureSource 2 (WF2CB). This narrows the field, but it is a hint, not proof – still verify the printed model.

If you want a guided walk-through that asks for your model and returns the matching cartridge, our which-filter-fits finder does exactly that. It will not override the number printed on your current filter, though – that printed number is always the final word.

Why the PureSource Generations Are Not Cross-Compatible

It is tempting to assume a newer filter is simply a “better” version that drops into an older slot. It is not. The cartridges differ in length, diameter, port geometry, and how they lock in. The WF3CB is about 9 inches long and twists in; the ULTRAWF is shorter and pushes in with a quarter-turn click; the EPTWFU01 uses a different keyed interface again. Force the wrong one and you either cannot seat it or you break the seal and bypass filtration entirely – water flows, but unfiltered.

This is the trade-off Frigidaire made by redesigning the cartridge over the years: each generation seals better or installs more easily than the last, at the cost of backward compatibility. That is honest engineering, but it means there is no universal Frigidaire refrigerator water filter. The correct answer is always “the one your specific fridge was built to seat.”

If you are weighing a genuine Frigidaire cartridge against an aftermarket equivalent, the fit question and the certification question are separate. A third-party filter can match the body shape and still make weaker performance claims – or stronger ones it has not independently certified. Treat fit and filtration as two checks, not one.

What the NSF Certifications Actually Mean

Filter listings throw around “NSF certified” loosely. Two standards matter most for a refrigerator filter, and they are not the same promise:

• NSF/ANSI 42 covers aesthetic effects – chlorine taste and odor, and some particulates. This is the comfort tier. It does not speak to health contaminants.
• NSF/ANSI 53 covers health effects – lead, cysts (Cryptosporidium and Giardia), mercury, and other contaminants with a health basis. This is the tier that matters if lead is your concern.

Genuine Frigidaire PureSource cartridges such as the ULTRAWF are tested and certified to NSF/ANSI 42 and 53, and the Ultra-class filters add NSF/ANSI 401 (the standard for “emerging contaminants” like trace pharmaceuticals). The Ultra-class cartridge uses a roughly 0.5 micron carbon block, which is what lets it make particulate and cyst claims rather than taste-only claims.

The honest caveat: an NSF 53 lead claim is SKU-specific, not brand-wide. A filter line being “NSF certified” tells you almost nothing on its own – a cartridge can be certified to 42 only and still wear the NSF mark. This matters most with aftermarket filters, where the marketing copy and the actual certified scope often diverge. Before you trust any lead-reduction claim, look up the exact model number in NSF’s official listings at info.nsf.org and confirm Standard 53 and lead are both listed for that specific SKU.

Lead is worth the diligence. The EPA’s regulatory action level for lead in drinking water is 15 ppb, and NSF tightened the pass/fail criterion for certified lead-reduction units to 5 ppb – but those numbers only protect you if the filter you actually installed carries the certification, not just the brand family. The EPA also maintains guidance on identifying filters certified to reduce lead. If you are on a private well or an older service line, certified lead reduction is a feature to confirm, not assume.

When a Refrigerator Filter Is Not the Right Tool

A PureSource cartridge is a point-of-use polish for the water and ice coming out of one appliance. It is excellent at chlorine taste, odor, particulates, and – on the Ultra-class SKUs – certified health contaminants. It is not a whole-home solution, and it does not address two common water problems at all.

If your real issue is hardness – scale on fixtures, spotty glassware, soap that will not lather – a fridge filter does nothing for it. That is a water softener’s job, and sizing one correctly matters; our water softener sizing calculator walks the grain-capacity math. If you are after near-complete contaminant removal across the whole kitchen, a reverse-osmosis system is the heavier tool; you can weigh the long-run cartridge and membrane costs with our reverse osmosis cost calculator before committing. Matching the tool to the actual problem saves money – a $40 fridge cartridge cannot fix hardness, and a $400 RO unit is overkill if all you wanted was better-tasting ice.

Frequently Asked Questions

Can I use a WF3CB in place of an ULTRAWF?

No. The WF3CB (PureSource 3) is a twist-in cartridge and the ULTRAWF (PureSource Ultra) is a push-and-click cartridge with different body geometry. They are not interchangeable. Confirm the model printed on your current filter before ordering – one Frigidaire fridge line uses different filters across model years.

How long does a Frigidaire PureSource filter last?

Frigidaire generally rates its PureSource cartridges for about 6 months or roughly 200 gallons, whichever comes first. Hard water, sediment, or heavy dispenser use can shorten that. Many models track usage and turn on a “replace filter” indicator; replace on the indicator or the 6-month mark, not on taste alone, since a filter can exhaust its capacity before the water tastes noticeably worse.

Does the Frigidaire ULTRAWF filter remove lead?

The genuine ULTRAWF is certified to NSF/ANSI 53, which covers lead reduction, in addition to NSF/ANSI 42 (taste and odor) and 401. Verify the exact cartridge you buy carries the Standard 53 lead listing at info.nsf.org before trusting a lead claim – this is especially important with aftermarket filters, where the certified scope may be narrower than the marketing implies.

Is an aftermarket Frigidaire filter as good as the genuine one?

Sometimes, but you have to check two things separately: does it physically seat in your slot, and does that specific SKU carry the NSF certifications it claims. A good aftermarket filter matches the body shape and independently certifies its performance; a poor one matches the shape but certifies only NSF 42 while implying health-grade filtration. Look up the exact model in NSF’s listing rather than trusting the product page.

Where is my refrigerator’s model number?

Look inside the fresh-food compartment – along the top edge, on a side wall, or near the crisper drawers. It is on a printed or stamped label. Use that full model number (including any trailing revision digits) to confirm your filter, since two visually similar Frigidaire fridges from different years can take different PureSource cartridges.

The Bottom Line

There is no single Frigidaire refrigerator water filter. There are at least five PureSource-family cartridges – WF2CB, WF3CB, ULTRAWF, EPTWFU01, and the standalone PWF-1 – and the generations do not interchange. Identify yours by reading the printed model on your current filter or your refrigerator’s model number, not by the brand on the door. Then, if lead matters to you, verify the exact SKU’s NSF/ANSI 53 listing before you trust the claim. Match the generation, confirm the certification, and you will buy the right filter once.

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Sources and further reading:

• Frigidaire, PureSource 3 (WF3CB) water filter product page
• Frigidaire, PureSource Ultra II (EPTWFU01) water filter product page
• NSF International, official Drinking Water Treatment Unit certification listings
• NSF International, stricter lead-reduction certification requirements
• U.S. EPA, guide to identifying drinking water filters certified to reduce lead