Water Filter for the LG LFX31925ST (LT700P)

LFX31925ST specifics — where the filter actually lives

Finding the bay is the easy part — this chassis puts it in the fresh-food compartment, typically the upper back wall in most French-door layouts, the same estate every French-door refrigerator in this family uses. It is a push-twist bay — press, quarter-turn, finished — the two-step seat keeps the o-ring from dragging on installation.

Two quirks worth knowing before you order: carbon fines in the first pours are normal for a fresh bed, and the filter timer only restarts when you hold the reset. LF is not a trim code, it is a chassis statement: when LG stamps LF on the plate it is sorting the machine into the French-door class — same water path, same cartridge, different cabinet. The ST tail marks finish variants of one chassis; the filter bay is shared across the entire finish range.

LF vs LS — what the prefix tells you

The LF/LS pair divides this family by layout — LF marks French-door builds and LS marks side-by-side builds. Cross-checking the prefix before ordering is faster than returning the wrong cartridge. Size class 31 cubic feet — worth knowing because a full household works a cartridge harder than the rated six months assumes.

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

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.

LFX31925ST filter questions