Almost every LG refrigerator with a dispenser routes its water through a cartridge filter before the water reaches the dispenser and the ice maker. As the filter loads with sediment, flow drops. The first symptom is a dispenser that takes noticeably longer to fill a glass; the second is ice that comes out small, cloudy or hollow because the ice maker mould did not fill fully before it froze. Both look like faults and both are usually maintenance.
How the Reminder Works
The filter indicator on the panel is a timer, not a sensor. It counts down from installation over the interval LG specifies for that model, which is six months on most current models, and turns on regardless of how much water has passed through. In a household that uses a great deal of ice, or one with hard or sediment-heavy water, the filter can be exhausted before the light comes on. Judge by flow as well as by the light, and reset the indicator after each change by holding the filter button as the manual describes.
Changing It
LG puts the filter in one of a few places depending on the model: inside the fresh-food compartment at the upper left, behind a flip-down cover in the ceiling, or in the door. The manual shows which. Turn the ice maker off first so it does not try to fill mid-change, and hold a towel under the housing because a little water always escapes. Twist or pull the old cartridge out according to the housing type, remove the caps from the new one, push it in and turn until it locks. Then flush it: dispense water for the period the instructions give, typically a few gallons in short bursts, until it runs clear and free of air. Discard the first few batches of ice the ice maker produces afterwards.
Use a Filter That Fits
Cartridges that look alike do not all seal alike. A cartridge that was not made for the housing can pass water around its seals, drip inside the compartment or reduce flow more than the one it replaced. Check the part designation on the old filter or in the manual before buying.
When a New Filter Changes Nothing
If flow is still poor immediately after a correct filter change, the restriction lies elsewhere. Close the refrigerator's water supply valve before you inspect anything on the supply side. The common suspects are a kinked supply line behind the cabinet, a saddle valve on the household pipe that has clogged or was never fully opened, and, on models with the water line running through the freezer door, a frozen section of that line. A frozen door line is usually a freezer set colder than it needs to be; setting it to 0°F and waiting a day often restores flow. Ice-maker output that stays poor with good dispenser flow points at the ice maker itself, its fill valve or a freezer that is not cold enough, and LG's craft ice makers produce their spheres slowly by design.
Booking a Look
If the dispenser is slow after a new filter, the line is clear and the freezer is at temperature, the water inlet valve or the dispenser assembly needs testing, which is done with the refrigerator disconnected from power and the water valve closed. Book an LG refrigerator repair and say when the filter was last changed, what the dispenser does and what the ice looks like.