CUNO Water Filter Systems Cross-Reference Guide: Every Model Mapped to 3M & OEM Alternatives

If you are searching for a “CUNO water filter,” you are not alone — and you are not behind the times. Tens of thousands of commercial kitchens, whole-house installations, and industrial facilities worldwide still have CUNO filter heads on the wall, CUNO model numbers on their maintenance logs, and “CUNO” on the label of the housing they have been buying cartridges for since the early 2000s.

The brand disappeared from the market in 2005 when 3M acquired CUNO Inc. for $1.36 billion, folding its water filtration technology into the 3M Water Filtration (commercial) and 3M Aqua-Pure (residential) product lines. The hardware is identical — only the brand name changed. But the branding transition created a persistent sourcing problem: building managers, maintenance technicians, and distributors see “CUNO” on the installed equipment and cannot find “CUNO” in current supplier catalogs. They need a cross-reference.

This guide is that cross-reference. It maps every commonly encountered CUNO model to its current 3M equivalent, identifies which systems accept lower-cost OEM-compatible cartridges, and provides the technical specifications that matter for replacement decisions.

CUNO to 3M: The Brand History in 60 Seconds

Year	Event
1936	Commercial Filters Corporation founded (later renamed CUNO)
1960s-90s	CUNO becomes a leading name in commercial/industrial water filtration; develops CFS foodservice line and Aqua-Pure residential line
2005	3M acquires CUNO Inc. — all product lines absorbed into 3M
2005-2010	Dual branding period — labels show “3M CUNO” or “CUNO by 3M”
2010+	CUNO brand fully phased out; products sold as “3M Water Filtration” (commercial) and “3M Aqua-Pure” (residential)
2024	3M spins off its filtration business into Solventum; commercial water filtration remains under 3M

Practical takeaway: A “CUNO filter,” a “3M CUNO filter,” a “3M Aqua-Pure filter,” and a “3M Water Filtration” cartridge are all part of the same product ecosystem. If you have CUNO hardware, you order 3M replacements — or, for standard-housing systems, OEM-compatible alternatives at 30-50% lower cost.

How CUNO / 3M Filter Systems Work

CUNO systems fall into two fundamentally different platform architectures, and this distinction determines your replacement options:

1. Standard Housing Systems (Open Platform)

The majority of CUNO residential and legacy commercial installations use industry-standard filter housings — 10-inch or 20-inch cylindrical housings that accept any correctly sized cartridge. The housing has a sump (bowl) that unscrews, the old cartridge drops out, and a new one drops in. No proprietary interface.

• Residential whole-house: AP801, AP802 series (20” big blue housings)
• Residential undersink: AP200 series (standard 10” housings)
• Legacy commercial: CFS housings with drop-in CFS cartridges
• Replacement options: Any standard-format cartridge that matches the size, end cap configuration, and micron rating — including OEM-compatible cartridges from third-party manufacturers

2. SQC Systems (Proprietary / Locked Platform)

3M’s Sanitary Quick Change (SQC) valve-in-head system is used on modern commercial/foodservice installations (HF series, ICE series, BEV series). The cartridge has a proprietary interface that mates with a valve built into the head — when the cartridge is removed, the valve automatically shuts off water flow. Convenient, but it means only 3M SQC cartridges fit these heads.

• No generic alternatives exist for SQC
• Replacement cost is 3M’s list price, always
• This is the platform lock-in that the cost comparison guide documents in detail

For a deeper explanation of the 3M product families, SQC mechanics, and commercial model lines, see the full 3M / CUNO / Aqua-Pure water filter guide.

Complete CUNO-to-3M Cross-Reference Table

Commercial / Foodservice (CFS Series)

These are the cartridges found in restaurants, coffee shops, ice machine lines, convenience stores, and institutional kitchens.

CUNO Model	Current 3M Model	Type	Micron	Capacity	Flow Rate	Housing/Interface
CFS8110-S	3M CFS8110-S	Carbon block (scale inhib.)	5 µm	2,000 gal	1.5 GPM	Standard CFS housing
CFS8112-S	3M CFS8112-S	Carbon block (scale inhib.)	1 µm	7,500 gal	1.5 GPM	Standard CFS housing
CFS8112EL-S	3M CFS8112EL-S	Carbon block (scale inhib.)	1 µm	10,500 gal	1.5 GPM	Standard CFS housing (extended length)
CFS8720-S	3M CFS8720-S	Carbon block	5 µm	5,000 gal	1.5 GPM	Standard CFS housing
CFS8812X-S	3M CFS8812X-S	Carbon block (scale inhib.)	0.5 µm	6,000 gal	1.5 GPM	Standard CFS housing
CFS9112-S	3M CFS9112-S	Carbon block (scale inhib.)	1 µm	7,500 gal	1.5 GPM	Drop-in
CFS9720-S	3M CFS9720-S	Carbon block	5 µm	12,000 gal	2.5 GPM	Drop-in
CFS9112EL-S	3M CFS9112EL-S	Carbon block (scale inhib.)	1 µm	18,000 gal	2.5 GPM	Drop-in (extended length)
CFS117-S	3M CFS117-S	Sediment/carbon	5 µm	10,000 gal	2 GPM	Standard CFS housing

Important: CFS-housing models use standard drop-in cartridges. For these, OEM-compatible cartridges matching the physical dimensions (diameter, length, end cap type) and micron rating are available from certified manufacturers. This is where operators running older CUNO equipment can realize significant savings.

Modern 3M SQC Replacements for Legacy CUNO Positions

When upgrading from a worn-out CUNO CFS housing to a current 3M system, the typical migration path is to an SQC head. The trade-off: more convenient cartridge changes, but permanent vendor lock-in.

Legacy CUNO Application	Current 3M SQC Replacement	Capacity	Notes
CFS8112-S (ice machine)	ICE125-S or ICE145-S	9,000-18,000 gal	SQC head + cartridge kit
CFS8112-S (coffee)	HF25-S or HF35-CLS	3,342-6,800 gal	0.2-1 µm, fine filtration
CFS8720-S (fountain)	BEV130 or BEV140	9,000-18,000 gal	Multi-line capable
CFS8110-S (general)	HF20-S	5,000 gal	Entry-level SQC

Our recommendation: If your CUNO CFS housings are still functional, keep them. Switching to standard-format OEM-compatible cartridges gives you the same water quality at 30-50% lower recurring cost, with no vendor lock-in. Only switch to SQC if the housing is genuinely end-of-life and you value the tool-free cartridge change enough to accept the 3M-only pricing permanently.

Residential / Whole-House (Aqua-Pure AP Series)

These are the systems installed in homes, small offices, and light-commercial buildings for whole-house sediment filtration and point-of-use drinking water.

CUNO Model	Current 3M Model	Type	Micron	Size	Housing
AP110	3M AP110	PP sediment	5 µm	10” (9.75”)	Standard 10” sump
AP117	3M AP117	Carbon block	5 µm	10” (9.75”)	Standard 10” sump
AP124	3M AP124	GAC (granular carbon)	25 µm	10” (9.75”)	Standard 10” sump
AP810	3M AP810	PP sediment	5 µm	20” (19.5”)	AP801/802 big blue housing
AP810-2	3M AP810-2	PP sediment	5 µm	20” (19.5”)	AP801/802 big blue housing
AP811	3M AP811	PP sediment	25 µm	20” (19.5”)	AP801/802 big blue housing
AP817	3M AP817	Carbon block	5 µm	20” (19.5”)	AP801/802 big blue housing
AP801	3M AP801	Housing (not cartridge)	—	20” big blue	Whole-house, 3/4” ports
AP802	3M AP802	Housing (not cartridge)	—	20” big blue	Whole-house, 1” ports

All AP-series housings use standard cartridge sizes. A CUNO AP810 is dimensionally identical to any 20” × 4.5” big-blue PP sediment cartridge from any manufacturer. OEM-compatible replacements in the same micron rating perform identically at a fraction of the cost. For a complete cartridge sizing guide, see water filter cartridge size compatibility chart.

Technical Specifications: What to Match When Replacing CUNO Cartridges

When cross-referencing a CUNO cartridge to an OEM-compatible replacement, match these five parameters:

Parameter	What to Check	Why It Matters
Physical dimensions	Length (9.75”/10”, 19.5”/20”) and diameter (2.5” standard, 4.5” big blue)	Must fit the housing — too long or too wide won’t seat
End cap configuration	DOE (double open end), SOE (single open end), or proprietary bayonet	Wrong end cap = no seal = bypass = unfiltered water
Micron rating	Match the original (1, 5, 10, 25 µm)	Lower micron = finer filtration but faster pressure drop; higher micron = coarser, longer life
Media type	PP sediment, GAC, CTO carbon block, carbon with scale inhibitor	Determines what the cartridge removes — don’t substitute GAC where carbon block is specified
Flow rate	Match or exceed the original rated GPM	Under-rated flow causes excessive pressure drop and premature exhaustion

For a deeper dive into filter media types and when each is appropriate, see water filter cartridge materials guide: PP vs carbon block vs RO vs UF.

The OEM Alternative: Where CUNO Users Save Money

The CUNO-to-3M transition actually created an opportunity for end users. During the CUNO era, most installations used standard-housing systems with drop-in cartridges. When 3M acquired the line, they introduced the proprietary SQC platform for new commercial installations — but the millions of existing CUNO standard housings remain in service and continue to accept any correctly sized cartridge.

For these standard-housing systems, OEM-compatible cartridges deliver identical performance at 30-50% lower cost:

CUNO/3M Model	Media	Original 3M Price (approx.)	OEM-Compatible Price	Savings
AP810 (20” PP, 5µm)	PP melt-blown	$18-25	$8-14	40-55%
AP817 (20” carbon block)	Coconut carbon block	$45-65	$22-38	40-50%
CFS8112-S (commercial carbon)	Carbon block + scale	$85-120	$45-70	35-45%
AP110 (10” PP, 5µm)	PP melt-blown	$8-12	$3-6	50-60%

For a single household whole-house system replacing two cartridges per year, the savings are modest ($20-60/year). For a property management company maintaining 50 units, a restaurant group with 20 locations on CFS housings, or a distributor supplying hundreds of accounts, the savings compound into meaningful numbers — and the ability to launch a private-label cartridge brand under your own name opens a recurring revenue channel.

Migration Decision Tree: Keep CUNO Housing vs. Upgrade

Situation	Recommendation
CUNO standard housing in good condition	Keep it. Switch to OEM-compatible cartridges, save 30-50% on every replacement.
CUNO housing cracked, leaking, or corroded	Replace with a new standard housing (not SQC) to maintain open-platform flexibility.
Building manager wants tool-free cartridge changes	Consider 3M SQC — accept the vendor lock-in trade-off. Or install an Everpure-style bayonet system, which offers tool-free changes with an open cartridge market.
Facility upgrading to Everpure platform	Excellent choice for long-term cost flexibility. See the Everpure cross-reference chart for the full model lineup.
Distributor evaluating platforms for new accounts	Recommend Everpure-style bayonet systems — open cartridge market means you can supply OEM-compatible or private-label cartridges at your margin, not the OEM’s.

Frequently Asked Questions

What happened to CUNO water filters?

CUNO Inc. was acquired by 3M in 2005 for $1.36 billion. The CUNO brand was folded into 3M Water Filtration (commercial) and 3M Aqua-Pure (residential). Legacy CUNO model numbers continue on installed equipment, but all current production uses 3M branding. The products themselves are identical.

Are CUNO and 3M Aqua-Pure water filters the same?

Yes. They are the same product line under different branding. A CUNO AP810 and a 3M AP810 are the identical cartridge. A CUNO CFS8112-S and a 3M CFS8112-S are the same part. No design changes were made during the transition.

Can I use generic cartridges in my CUNO whole-house filter?

Yes — if your system uses standard 10” or 20” housings (AP801, AP802, or standard CFS drop-in housings). These accept any industry-standard cartridge matching the size and end cap configuration. OEM-compatible cartridges at 30-50% lower cost are widely available. Check the size compatibility chart to confirm your dimensions.

How do I know if my CUNO system is standard or SQC?

Look at the cartridge interface. Standard systems have a sump (bowl) that unscrews — the cartridge simply drops in and out. SQC systems have a valve-in-head design where the cartridge twists to lock and the valve closes automatically when the cartridge is removed. If it twists to lock (quarter-turn, no unscrewing), it is SQC and requires 3M cartridges only.

Where can I get OEM-compatible cartridges for my CUNO system?

Contact our team with your CUNO model number and we will cross-reference it to a compatible replacement. For standard-housing systems, we manufacture drop-in replacements in all common sizes (10”, 20”, big blue) and media types (PP, GAC, CTO, carbon block). MOQ starts at 200 pcs for private label, lower for neutral packaging.

Summary

CUNO water filters did not disappear — they became 3M. The hardware on millions of walls worldwide still works exactly as it did before the acquisition, and the model numbers still cross-reference directly to current 3M catalog numbers.

For facilities running CUNO standard-housing systems (the majority of legacy installations), the smartest move is to keep the housing and switch to OEM-compatible cartridges — same filtration performance, same dimensions, same materials, 30-50% less per cartridge. For facilities considering a platform upgrade, an Everpure-style bayonet system offers the best long-term combination of water quality, convenience, and open-market pricing flexibility.

Need a cross-reference for your specific CUNO model? Send us the model number and we will match it to a compatible cartridge within 24 hours.