The model number decides, not the feature list
ULTRAWF is sold as PureSource Ultra, while WF3CB is sold as PureSource 3. Frigidaire assigns different product numbers and different alternate-part-number lists to them. A shared location, installation verb, flow rating, or certification standard cannot turn one family into the other.
Find the permanent appliance label rather than reading only the badge on the door. Copy every character, including the suffix. Frigidaire’s product pages include a compatibility field where the appliance model can be entered, and its support guidance says the owner’s manual provides model-specific filter information. If the lookup, manual, and old cartridge disagree, preserve photos and ask Frigidaire to resolve the complete model before ordering.
The loose filter is supporting evidence only. A previous owner may have inserted the wrong part, a service record may use an abbreviated family name, and a marketplace title may combine unrelated search terms. The model record is stronger evidence.
For a repeatable lookup workflow, use Which Frigidaire refrigerator water filter fits my refrigerator?.
Side-by-side facts from Frigidaire
This table is useful after compatibility has been established. It is not a cross-fit chart. Even when headline specifications match, connection geometry, housing engagement, seals, and model approvals remain family-specific.
Frigidaire lists alternate numbers for ULTRAWF including 241791601, 242017801, 242017805, and 242294401. Its WF3CB page instead lists numbers including 242069601, 242069603, 242086203, and 242294501. Treat those as family-specific official references, not an invitation to bridge the two lists.
What the certification language really means
Frigidaire states that each system is tested and certified by NSF International against NSF/ANSI Standards 42, 53, and 401 for the reduction claims on its performance data sheet. Standard 42 generally addresses aesthetic effects such as taste and odor claims; Standard 53 covers specified health-effect claims; Standard 401 addresses specified emerging compounds or incidental contaminants. The exact certified reductions and test conditions remain those named in the exact sheet.
Do not convert “certified to 42, 53, and 401” into “removes everything covered by those standards.” Certification applies to stated claims for an identified model or system. It also does not certify that a similarly shaped cartridge fits your refrigerator. NSF advises consumers to check the certification mark, standard, and specific contaminant claims, not merely a vague “tested” statement.
Frigidaire also states that its genuine filters carry Water Quality Association sustainability certification to WQA/ASPE/ANSI S 803. That is separate from contaminant-reduction certification. Keep sustainability, filtration performance, and appliance fit as three different checks.
Strict purchase gate for ULTRAWF
Choose ULTRAWF only if the complete refrigerator model is confirmed for ULTRAWF by Frigidaire’s compatibility checker, current model documentation, or Frigidaire support. The verified genuine ULTRAWF offer associated with this guide is Amazon ASIN B002JAKRAM. Before checkout, confirm that the live listing identifies Frigidaire, ULTRAWF/PureSource Ultra, the intended quantity, and a trustworthy seller. Do not use this ASIN for a model that calls for WF3CB, WF2CB, EPTWFU01, FPPWFU01, or another family.
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Strict purchase gate for WF3CB
Choose WF3CB only if the complete refrigerator model is confirmed for WF3CB by Frigidaire’s compatibility checker, current model documentation, or Frigidaire support. The verified genuine WF3CB offer associated with this guide is Amazon ASIN B0045LLC7K. Recheck the live title, Frigidaire branding, WF3CB/PureSource 3 identity, quantity, and seller before buying. A refrigerator confirmed for ULTRAWF does not pass this gate merely because the cartridge appears similar.
If WF3CB is confirmed, the dedicated Frigidaire WF3CB replacement guide covers the physical change and post-installation checks.
Installation similarities still do not prove substitution
Frigidaire describes both filters as push-to-lock designs. For the correct cartridge, the general pattern is to slide it into its housing and push until it locks. Always defer to the appliance manual, support the housing, and work by hand. If the filter will not enter squarely or will not latch with normal pressure, stop. Trimming a key, moving seals, forcing the cover, or using pliers can damage the receiver and create a pressurized leak.
Use New Frigidaire refrigerator water filter won’t go in if a model-confirmed filter resists installation. Resistance is a diagnostic clue, not a reason to try the competing family.
Once installed, Frigidaire instructs users to run water for approximately three minutes, or 1.5 gallons, to prime the filter and discard that water. Dispense in manageable intervals, inspect the connection and floor, and check again after the ice maker cycles. Follow the exact manual if its procedure differs.
The Frigidaire new-filter flushing guide explains how to measure the purge without confusing a dispenser cutoff with completion.
Replacement timing is a limit, not a promise
Both current pages say to replace by six months or 200 gallons, whichever comes first. Frigidaire also notes that larger households, frequent dispenser use, or high sediment may justify earlier replacement. Flow, taste, odor, a filter indicator, prolonged disuse, and local water conditions can all prompt review.
Do not extend service merely because water still comes out. Conversely, do not diagnose a wrong family solely from a six-month reminder; the indicator usually tracks time or use rather than reading the cartridge’s certified performance. Record the installation date, exact family, purchase source, purge amount, and any change in flow.
If the wrong one is already installed
Do not keep pushing, twisting, or dispensing to “see if it settles.” Photograph the old and new labels, housing, appliance model tag, and any leak or control message. If water is escaping, stop dispensing and close the dedicated supply valve if it is safe and accessible. Protect electrical areas.
If the cartridge is dry and fully seated but the family conflicts with official model documentation, ask Frigidaire for removal and replacement guidance. Do not assume that temporary water flow proves a safe seal or certified application. For active leakage, move directly to New Frigidaire refrigerator water filter leaking.
Final Verdict
ULTRAWF and WF3CB share several headline specifications, but the choice is not a contest between two equivalent filters. They are distinct PureSource families. Use the complete refrigerator model to pass a strict compatibility gate, then select the verified genuine ASIN for that confirmed family: B002JAKRAM for ULTRAWF or B0045LLC7K for WF3CB. If the evidence is incomplete, do not buy either yet. Confirm with Frigidaire, install without force, purge the documented amount, and inspect for leaks.
For more model-first maintenance help, visit the Frigidaire refrigerator guide library.
Official and certification sources