How to Change an LG Refrigerator Water Filter (LT1000P Twist & Turn, Every Model)
Changing an LG refrigerator water filter is a three-step twist job that takes under three minutes: open the filter cover (left refrigerator door interior or the top-left of the fresh-food compartment on most French-door models), grip the old cartridge and twist it counterclockwise about a half-turn until it releases, then pull it straight down and out; seat the new cartridge and twist clockwise until it locks; dispense about two gallons to purge air and carbon fines, then reset the filter indicator from the panel or the ThinQ app.
LG’s cartridge lineup is smaller and more orderly than GE’s — three LT numbers cover nearly everything — but two LG-specific traps make the difference between a clean swap and a support call: the 2025 notch change on replacement cartridges that has some newer tanks and older cartridges disagreeing, and the air filter sitting next to the water filter in many door-panel assemblies, which turns “water filter” searches into wrong-box purchases. Both are covered below, along with the LT-number decision table and the price bands.
Which LT Cartridge Does Your LG Take?
Three part numbers cover the modern LG fleet, with capacity — not fit — being the main difference:
| Cartridge | Capacity rating | Typical models | Notes |
|---|---|---|---|
| LT1000P / ADQ74793501-02 | 200 gallons / 6 months | Most current French-door and bottom-freezer | The volume seller; “Twin” two-packs serve dual-filter models |
| LT700P / ADQ36006101 | 200 gallons / 6 months | Slim French-door (LFXC22526 etc.) | Shallower cartridge for shallow housings |
| LT500P / ADQ72610901 | 200 gallons / 6 months | Older side-by-side, some bottom-freezer | Legacy line; check the Kenmore cross-reference before ordering |
Read the number off the old cartridge’s label first. If the cartridge is already gone, the model number plate lives inside the fresh-food compartment on the left wall (format LFXS26973S or LRMDS3006S). Two wrinkles our order desk handles weekly:
- Kenmore 795-series refrigerators are LG-built and take the same LT cartridges under Kenmore part numbers (46-9980 is the LT1000P cross). The Kenmore side of the story is covered in our Kenmore filter guide.
- “Twin” packs exist because some LG models run two cartridges. Dual-filter door assemblies use two of the same cartridge on the same six-month clock. Check for a second housing before ordering a single.
The 2025 notch change: check before you buy
LG’s current-generation cartridges carry a notch redesign introduced in 2025, and our compatibility-risk database flags it explicitly: “notch design change 2025 — verify tank slot version.” In practice: a cartridge from older inventory can seat imperfectly in a newer tank slot, and owners have reported slow seeps and filter-position errors after force-fitting an old-notch cartridge into a new-notch slot. Three rules handle it:
- If your refrigerator was manufactured in 2025 or later, buy current-production cartridges (not old-stock clearance lots) and confirm the seller’s stock is the new-notch version.
- If the cartridge meets noticeable resistance partway into the twist, stop and compare the notch pattern on old and new cartridges against the slot — force-fitting is how housings crack.
- A drip that starts right after a cartridge change on a 2025+ model is a notch mismatch suspect first, seating error second. The full leak-point diagnosis is in refrigerator water filter leaking.
This notch detail is exactly the kind of change that ranking competitor pages — mostly written once and date-stamped annually — do not track. It is the first thing we verify when an LG customer reports a brand-new cartridge that “just drips.”
The Change, Step by Step
LG’s twist-and-turn mechanism, consolidated from LG’s own guidance:
- Locate and open. Left door interior panel on most French-door models; upper-left rear of the fresh-food compartment on some bottom-freezers; behind the top grille on older side-by-sides. Open the cover — some swing, some lift.
- Twist and pull. Grip the cartridge base, turn counterclockwise about a half-turn (you will feel the lock release), and pull the cartridge straight out along its axis. Keep a towel at the housing — an ounce or two of water follows the cartridge.
- Prep the new cartridge. Remove the packaging and any protective cap on the O-rings. Confirm both O-rings ride evenly in their grooves.
- Insert and lock. Push the cartridge in until it bottoms, then twist clockwise until it locks — a clear detent, not a mushy stop. A half-twist that never quite firms up means the notches are not aligned; back it out, realign, retry.
- Purge. Dispense about two gallons, in pulses if your model’s dispenser prefers it. Sputtering is air; gray tint is carbon fines; both clear in the first gallon. Dump the first two ice batches.
No water-valve shutoff is required — the housing auto-shuts as the cartridge twists free.
Reset: Panel or ThinQ, Two Paths
LG filter indicators are six-month timers, and clearing them goes through one of two paths:
- Panel: press and hold the Filter button (or Filter Reset) about 3 seconds until the indicator clears or cycles to fresh. Exact button labels vary by panel generation — check your model’s manual page for the label, and see our LG filter reset guide for the full panel matrix.
- ThinQ app: open the app, select the refrigerator, open its settings/consumables section, and reset the water filter indicator from there — the path that owners of app-connected models keep asking about, and that most competitor pages skip entirely.
A flashing versus steady indicator means different things on some LG panels (approaching-due versus overdue); the decoding table is in the reset guide linked above.
The Air Filter Sitting Next Door
Many LG French-door models carry an LT120F fresh-air filter in the same door-panel area as the water cartridge. The two look nothing alike, but the order pages do not always make the distinction obvious, and swapping the words puts the wrong box on the shelf. The LT120F handles odors in the cabinet air; the LT-series water cartridge handles the dispenser line. If your model has both, LG’s service intervals align them at six months, which makes a same-day double swap the sensible routine — one flush session, one reset cycle.
OEM vs Compatible Pricing
Genuine LT1000P cartridges run in the $40-50 band (multi-packs bring the per-cartridge cost into the mid-$30s). The compatible market is deep, and the honest certification split is the same two tiers as every other brand: standard compatibles carry NSF 42 (taste, chlorine, particulates), premium compatibles add NSF 53 (lead, cysts, health-effect contaminants). Genuine LG cartridges carry 42, 53, and 401. The standard-by-standard meaning of each number is in NSF 42 vs 53, and the warranty context is in OEM vs aftermarket filters. One LG-specific note: because of the 2025 notch change, verify the compatible supplier is producing current-generation tooling — old-stock compatibles are the most common source of the drip complaints above.
Troubleshooting
- Cartridge will not release: scale and swollen O-rings. Twist-and-hold with steady downward pressure; if the head snaps, stop — the stuck-filter guide covers extraction without cracking the housing.
- New cartridge drips from the head: notch mismatch (2025+ tanks) or an O-ring fold. Recheck both before ordering a different cartridge.
- No water after the swap: air lock — hold the dispenser pad through two minutes of sputtering. Still nothing → not-working diagnosis.
- Filter position error on the display: cartridge not twisted to the detent. Re-seat and lock.
Frequently Asked Questions
How often should an LG water filter be changed? Every 6 months or 200 gallons, whichever comes first. Heavy ice-maker households and private-well supplies should treat four months as the realistic interval — the reasoning is in how often to change a refrigerator filter.
Can I reset the LG filter light from my phone? Yes, on ThinQ-connected models — open the app, select the fridge, and reset the water filter indicator in the appliance settings. The panel-button method works regardless of connectivity.
Is LT1000P the same as ADQ747935? Yes — ADQ74793501 through -03 are LG’s internal part numbers for the LT1000P retail cartridge. Same filter, different label generation.
Do Kenmore 795 refrigerators use LG filters? Yes. Kenmore 795-prefix models are LG-built and take LT-series cartridges under Kenmore 46- numbers. The prefix-decoding table is in the Kenmore guide.
What is the LT120F, and is it a water filter? No — the LT120F is the cabinet air filter for odors. It often sits near the water cartridge and shares the six-month interval, but it filters air, not water.
Related Guides
- How to Replace an LG Refrigerator Water Filter — LT500P/LT700P and legacy-model coverage, including the Kenmore cross-references.
- How to Reset the LG Filter Light — panel and ThinQ paths, flashing vs steady indicator decoding.
- Where Is the LG Water Filter? — locations by model style, including the ThinQ lookup path.
- LG Water Filter Bypass Plug — running unfiltered during a cartridge gap.
- NSF 42 vs NSF 53 Certification — what to demand from a compatible cartridge.