Water Filter for the LG LSC22991ST (LT800P)

LSC22991ST specifics — where the filter actually lives

The LSC22991ST 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. This is a push-twist style bay: the cartridge goes in square, then a short rotation locks it against the header — no tools involved.

Field notes: keep a folded towel under the bay before you open it; the line holds a cup of water even with the valve shut. The LS prefix is the tell: when LG stamps LS on the plate it is sorting the machine into the side-by-side class — same water path, same cartridge, different cabinet. That ST suffix is trim-level shorthand. LG kept the LT800P bay common to every finish in the line.

LS vs LF — what the prefix tells you

Same parts shelf, two cabinet missions — LS answers to side-by-side; LF answers to French-door; the water-filter answer is shared. the 22 cubic feet in the code is the size class; households that size move enough water that the six-month interval is worth honoring.

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.

LSC22991ST filter questions