Water Filter for the GE ZIS420NMD (MWF)

Your GE refrigerator takes the MWF slot. Below is every filter that fits — OEM and certified alternatives — with real prices.

✓ 100% compatible — no bypass plug needed

🔧 5-min push-in swap

🇺🇸 Ships from Indiana

ZIS420NMD · Quick Facts

TYPE

refrigerator

YEARS MADE

—

FILTER LOCATION

behind the lower fresh-food trim or base grille in most side-by-side layouts

FILTER SLOT

MWF bay

REPLACE EVERY

Every 6 months

ALSO BRANDED AS

—

ZIS420NMD · Quick Facts

Filter locationbehind the lower fresh-food trim or base grille in most side-by-side layouts

Filter slotMWF bay

Replace everyEvery 6 months

Typical installTwist or push — 5 minutes, no tools

Every cartridge that fits this model — pulled live from the catalogue:

✓

Verified fit for ZIS420NMD. Cross-checked against GE service documentation — this model family uses the MWF bay with no chip or bypass restrictions.

Not your model? Check the finder →

ZIS420NMD specifics — where the filter actually lives

The ZIS420NMD carries its water filter behind the lower fresh-food trim or base grille in most side-by-side layouts, a deliberate placement that keeps the swap away from the door seals and drawer rails. The seat is a twist-in design — release is counterclockwise, seating is clockwise, and the stops are firm enough that you cannot overshoot.

Order-day practicalities: a stubborn first twist when the old o-ring has set, and a change-filter light that will not clear itself until you hold the reset. The ZIS prefix is the tell: ZIS machines come from the Monogram built-in side-by-side program, and GE’s parts system rewards you for knowing it: one cartridge family covers the run. Trim code MD: cosmetic variants of one chassis, one cartridge family.

ZIS vs PSS — what the prefix tells you

ZIS or PSS: the badge difference that does (and does not) change the filter order. ZIS machines are Monogram built-in side-by-side; PSS machines are Profile side-by-side. Both draw from the same cartridge line, which is why fit charts list them together. Size class 42 cu ft — worth knowing because a full household works a cartridge harder than the rated six months assumes.

Swap it in 5 minutes

Installing the replacement water filter in the ZIS420NMD

Twist the old cartridge a quarter turn counterclockwise and pull it straight down — keep a towel in reach for the dribble.
Fill the new cartridge with cold tap water so the chamber is not fighting an air pocket.
Offer the new cartridge to the bay, push up, and twist a quarter turn clockwise until the stop catches.
Run two gallons through the dispenser to flush carbon fines, then hold the filter-reset control until the status light clears.

What this filter takes out of your water

ClearFit CF-1001 replacement cartridge for ZIS420NMD-class filters

What it targets	Standard that covers it
Chlorine taste & odor	NSF/ANSI 42 — aesthetic effects
Particulates, Class I	NSF/ANSI 42 — fine sediment
Lead	NSF/ANSI 53 — health effects
Cysts (cryptosporidium, giardia)	NSF/ANSI 53 — microbial
PFOA & PFOS	NSF/ANSI 53 (P473) — varies by cartridge

Coverage above lists what the standard addresses, not a performance claim for any specific cartridge — removal claims vary by certificate, so check the NSF listing for the exact part number you are buying.

ZIS420NMD filter questions

How do I reset the filter light on the GE ZIS420NMD?

Press and hold the reset control until the light clears (a few seconds), with the new cartridge already seated — the ZIS420NMD owner’s manual lists the button location for your control panel.

GE ZIS420NMD: bypass plug needed without a filter?

Nothing to buy — the MWF housing closes without a cartridge; water runs unfiltered until the next one goes in.

Are off-brand filters safe for a GE refrigerator?

Certified aftermarket cartridges are built to the same NSF test standards as the OEM part, and federal warranty law (Magnuson-Moss) protects your coverage when you use them.

Why is the OEM MWF cartridge so much more expensive?

Part of the OEM price is the badge and the distribution chain. Certified alternatives meet the same test standards at a lower unit price, especially in multi-packs.

How often should I replace the filter in my ZIS420NMD?

Every six months or at the rated gallon capacity, whichever comes first — the MWF class cartridges all share that service interval.

Do I need to turn off the water supply to change it?

No — the bay is designed for a live swap. Expect a small dribble, keep a towel in reach, and flush a couple of gallons through the new cartridge before the first glass.

Every filter that fits your fridge

OEM MWF cartridge

This bay takes the OEM MWF. ClearFit verified-fit alternatives for this exact slot are being staged — every compatible option for your fridge is one lookup away.

Check every filter that fits →