Water Filter for the LG LFX25978SB (LT700P)

LFX25978SB specifics — where the filter actually lives

The filter bay on the LFX25978SB top-left of the fresh-food compartment in most French-door layouts, away from the door bins, the same estate every French-door refrigerator in this family uses. This is a push-twist style bay: the cartridge goes in square, then a short rotation locks it against the header — no tools involved.

Before you click buy, two things: expect dribble at the bay on removal even with the supply off, and remember the indicator will not self-clear — hold the reset control. Decode the plate and the parts question answers itself: LF is LG’s own coding for French-door machines, and in that format the water path is long enough that a neglected cartridge shows up as flow drop before it shows up as taste. Trim code SB: cosmetic variants of one chassis, one cartridge family.

LF vs LS — what the prefix tells you

LF versus LS is the first fork in the parts catalog: French-door builds carry LF; side-by-side builds carry LS. Filter-wise the two lines converge on one cartridge family. 25 cubic feet of cabinet — the dispenser sees heavy traffic at that size, and heavy traffic ages cartridges faster.

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.

LFX25978SB filter questions