PUR Plus Faucet Filter Replacement (2026): RF-3375 vs Compatible
Guide
The indicator on your PUR faucet filter just turned red, and you are staring at the replacement shelf: the genuine RF-3375 at about $20, and a wall of “fits PUR” cartridges at half that. Faucet filters are cheap and simple, so is there any real difference? With this one, yes — the RF-3375 is the rare faucet cartridge with a genuine lead claim behind it.
Here is the short answer: buy the genuine PUR RF-3375. PUR lists the cartridge as certified to NSF/ANSI Standards 42, 53 and 401 — lead reduction included — which no faucet-mount compatible matches. It lasts 100 gallons or about 3 months. Compatibles at $7–10 save roughly $40 a year but fall back to taste-and-odor claims. On a fridge filter that trade can make sense; on the one faucet filter certified for lead, the genuine cartridge is the point of owning the system.
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Quick verdict
Buy the genuine RF-3375. It is one of the only faucet-mount cartridges anywhere listed as certified to NSF/ANSI 53 for lead reduction (plus 42 and 401), and the premium is small in absolute terms: roughly $18–22 a cartridge, four changes a year, $72–88 all-in. Compatibles make sense only if lead plays no part in why you filter — chlorinated taste on a known-clean municipal supply, where a $7–10 cartridge’s 42-style claims cover the job. If you bought the PUR Plus system specifically for its lead certification, a compatible quietly removes the reason. For the wider certified picture, see our NSF 53 certification explainer.
First, confirm the RF-3375 is your cartridge
PUR sells two faucet families, and they take different cartridges. The RF-3375 is the cartridge for PUR Plus (and earlier “Advanced”) systems — horizontal and vertical mounts with the MineralClear core and the filter-life indicator. The older RF-9999 serves the Basic systems. The two are not interchangeable, so check the cartridge number inside your housing (or the system name on the mount) before ordering. Also note the genuine packaging detail that matters: real RF-3375 cartridges come with the change-indicator reset built into the swap — the mount’s light goes back to green when a fresh cartridge seats.
Your replacement options, compared
| Option | Price per filter | Price per year (x4) | Certification | Best for |
|---|---|---|---|---|
| Genuine PUR RF-3375 | ~$18–22 | ~$72–88 | NSF/ANSI 42, 53, 401 listed by PUR — incl. lead | The certified lead claim |
| Compatible cartridge | ~$7–10 | ~$28–40 | NSF/ANSI 42-style claims at best; usually unverified | Taste-only filtering |
| Switching format instead | — | Varies | See each guide | If faucet mounts annoy you — pitchers such as ZeroWater cost out in our ZeroWater filter cost guide |
Every tier is rated around the same 100-gallon life, so the per-gallon math stays honest: genuine works out near $0.20 per gallon, compatibles near $0.08. What changes is not the water volume — it is which contaminants the paperwork covers.
Why the genuine cartridge matters here
Genuine RF-3375 — pros
- Certified lead reduction at the tap — PUR lists the RF-3375 to NSF/ANSI 53, a claim almost no faucet-mount cartridge (and no PUR-compatible) can make.
- The full 42/53/401 stack — chlorine taste, lead and particulates, and emerging contaminants in one $20 cartridge.
- The indicator system works as designed — the mount’s green-to-red light tracks the cartridge PUR built it for.
Genuine RF-3375 — cons
- Four changes a year — the 100-gallon life is the shortest in this guide series; heavy households swap more often.
- Filtered flow is slow — about half a gallon per minute; filling a stockpot tests patience.
- Cold water only — hot water damages the media, so the mount demands a small habit change.
A compatible cartridge does not void anything here — it is a $20 plastic mount, not a warrantied appliance — but it does quietly downgrade a lead-certified system into a taste filter. Decide with that on the table.
Changing the cartridge
A two-minute job: unscrew the housing cap over the sink, lift the old cartridge out, drop the new one in, and screw the cap back until snug. Run the filtered side for about 5 minutes to flush the new media, and the indicator resets to green. Two habits protect the cartridge: filtered side for drinking water only (use the unfiltered side for washing and hot water), and never run hot water through the filter — heat breaks down the media and the lead claim with it.
Conclusion
The RF-3375 is the exception that proves the compatible rule. On most cartridges the genuine premium buys marginal paperwork; on this one it buys the only certified lead claim in the faucet-mount category, for about $40 a year over compatibles. Buy the genuine PUR cartridge (roughly $18–22), change it every 100 gallons or 3 months, and keep hot water on the unfiltered side. If your concern is taste alone, a compatible is an honest saving — just know which claim you are setting down.
Update log
October 2026: Guide published with certification statements checked against PUR’s published RF-3375 product information and prices taken from current retailer listings.
FAQs
Does the PUR RF-3375 really remove lead?
PUR lists the RF-3375 as certified to NSF/ANSI Standard 53, which covers lead reduction, alongside Standard 42 (chlorine, taste, particulate) and 401 (emerging contaminants like certain pharmaceuticals). That listing is what makes this faucet cartridge unusual — most faucet mounts, and all of the compatibles we found, stop at taste-and-odor claims.
What is the difference between the RF-3375 and the RF-9999?
They serve different PUR faucet families. The RF-3375 is the Plus cartridge (MineralClear core, used in Plus and earlier Advanced systems with the filter-life indicator); the RF-9999 serves the older Basic systems. They are not interchangeable — match the number inside your housing.
How long does an RF-3375 cartridge last?
About 100 gallons or 3 months, whichever comes first. The mount’s indicator light tracks the interval from green through yellow to red. A household filtering all its drinking and cooking water may reach 100 gallons before the 3 months are up.
Are compatible RF-3375 cartridges worth it?
Only if lead is not part of your reason for filtering. At $7–10 they roughly halve the yearly cost, but their claims top out at taste-and-odor level and are typically unverified. Swapping one in quietly converts a lead-certified system into a taste filter.
Can I run hot water through my PUR faucet filter?
No. PUR specifies cold water only — hot water damages the filter media and destroys the reduction performance the cartridge is certified for. Use the mount’s lever to switch to the unfiltered side for hot water and washing up.
Why is the flow from my PUR filter so slow?
Some slowness is normal: filtered flow is about half a gallon per minute by design, because contact time is how the media works. Flow that keeps dropping usually means the cartridge is exhausting (change it) or was run with hot water at some point (which damages it permanently).
