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Water Filter for the LG LMX219781ST (LT600P)
✓ 100% compatible — no bypass plug needed
🔧 5-min push-in swap
🇺🇸 Ships from Indiana
Every cartridge that fits this model — pulled live from the catalogue:
✓
LMX219781ST specifics — where the filter actually lives
The LMX219781ST carries its water filter in the fresh-food compartment — exact spot varies by dispenser layout, so expect to clear one shelf edge before you have working room. This is a push-twist style bay: offer the cartridge to the header, press, and rotate until the stop catches; a towel handles the dribble.
Field notes: 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. One prefix, one chassis family: LM is LG’s 4-door Max designation proper, and the service literature files every one of these under the same cartridge line. ST is finish coding: handles, colors, panel options — none of it reaches the filter bay.
LM vs LF — what the prefix tells you
LM or LF: the badge difference that does (and does not) change the filter order. 4-door Max builds carry LM; French-door builds carry LF. Filter-wise the two lines converge on one cartridge family. read the code as 21 cubic feet of capacity, which tells you the cartridge’s real workload between changes.
Swap it in 5 minutes
- Press the release (if fitted), twist the old cartridge free, and pull it from the header.
- Wet the new cartridge’s o-ring with cold tap water so it seats without dragging.
- Push the cartridge square onto the header, then give it the locking quarter turn.
- 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
| 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.
LMX219781ST filter questions
Reset procedure for the change-filter alert on the LMX219781ST?
Press and hold the reset control until the light clears (a few seconds), with the new cartridge already seated — the LMX219781ST owner’s manual lists the button location for your control panel.
Can I run the LG LMX219781ST with no cartridge installed?
Nothing to buy — the LT600P housing closes without a cartridge; water runs unfiltered until the next one goes in.
Are off-brand filters safe for a LG 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 LT600P 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 LMX219781ST?
Every six months or at the rated gallon capacity, whichever comes first — the LT600P 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
This bay takes the OEM LT600P. 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 →This filter expires six months from today
Your HVAC filter is probably on a different cycle. Track them all in one place.
months until this filter should be replaced (200-gal rated life)
Free tool · tracks fridge + HVAC + whole-house · auto-refill optional
More models using this filter
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