The Check Valve is an OEM part for LG dishwashers. It prevents the backflow of water into the dishwasher, ensuring that water only flows in the intended direction. This helps maintain the efficiency of the washing cycle and prevents contamination of clean dishes. The check valve can fail due to reasons such as wear and tear, blockage from debris or hard water deposits, or damage from high water pressure. Over time, the internal components can degrade, leading to improper sealing. Symptoms of a bad check valve include: Water backing up into the dishwasher Poor cleaning performance due to improper water flow The dishwasher not draining properly Unusual noises during the wash or drain cycles This OEM LG part is also compatible with certain models of Kenmore dishwashers.This part fixes the following symptomsWill not drainPart Number 5220ED4004A (AP4442609) replaces 1268122, AH3527424, EA3527424, PS3527424.