LG LFC21770ST/05 refrigerator Parts

For the LG LFC21770ST refrigerator, the water filter typically lasts about 6 months under normal household use. If your water is hard, cloudy, or you dispense a lot of water and ice, plan on changing it sooner to keep taste and flow consistent.

Typical replacement timing

Most customers replace an LG refrigerator water filter on one of these schedules:

• Every 6 months (most common)
• Sooner if water flow slows at the dispenser
• Sooner if ice cubes get smaller or hollow
• Sooner if water tastes or smells off
• After plumbing work or a long period of non-use

For model-specific filter location and reset steps, follow the instructions in the LFC21770ST owner's manual.

Quick checks that tell you it is time

Use these practical signs before you wait out the full 6 months:

• Dispensed water is noticeably slower than before
• Ice production drops or cubes look irregular
• You see more air spurts after dispensing (often happens when a filter is restricted)
• Water has a chlorine taste or odor
• The filter has been installed for 6 months or longer

What changes the filter life?

Factor	What it does	What to do
Heavy dispenser use	Uses up capacity faster	Replace closer to 3 to 4 months
Sediment or hard water	Clogs media faster	Replace sooner; consider an inline filter
Long vacations	Water sits in the filter	Flush several gallons after returning
New filter install	Air in the line is common	Purge water until flow is steady

Why it matters

A fresh filter helps protect water taste, supports steady dispenser flow, and reduces strain on the refrigerator’s water system. Waiting too long can lead to slow dispensing and weak ice maker fill.

For step-by-step guidance, we recommend how to replace the water filter in an LG refrigerator.

Last updated: January 2026

To reset the lower ice maker on your LG LFC21770ST, you typically power-cycle the ice maker and run its built-in test or reset sequence, then confirm the ice bin is seated correctly so the ejector and shutoff arm can move freely. See the LFC21770ST owner's manual for the exact button location and reset steps.

Quick reset steps (most LG bottom-mount ice makers)

• Make sure the ice bin is pushed fully in and sitting level.
• Turn the ice maker OFF, wait 30 seconds, then turn it ON.
• If your ice maker has a TEST/RESET button: press and hold it for about 3 to 5 seconds until you hear a chime or the tray starts to move.
• Close the freezer drawer and wait for the reset cycle to finish (often a few minutes).
• Allow time for ice production to resume (commonly 12 to 24 hours for a full bin).

If it still will not reset or make ice

These checks solve most “lower ice maker not working” complaints on LG bottom-mount refrigerators:

• Freezer temperature: target about 0°F; warmer temps slow or stop ice production.
• Ice maker jam: remove the bin and clear clumped ice around the ejector area.
• Water supply: confirm the shutoff valve is open and the supply line is not kinked.
• Fill problem: if you hear no water fill after a reset, the refrigerator water inlet valve 5220JB2010A is a common suspect.
• Ice maker module issue: if the tray never cycles during reset, the ice maker kit AEQ72909603 may need replacement.

What to expect after a reset

What you see	What it usually means	What to do
Tray cycles and you hear a fill	Reset worked	Wait for ice to freeze and harvest
Tray does not move	Ice maker not getting power or failed	Recheck switch, wiring, then consider ice maker replacement
Tray moves but no water fills	Water supply or valve issue	Check supply, then test inlet valve

Why it matters

A proper reset confirms the ice maker can cycle and call for water. If the bin is misaligned or the freezer is too warm, the ice maker can appear “dead” even when the refrigerator is cooling.

Last updated: January 2026

Yes. On the LG LFC21770ST, the ice maker uses the same water supply as the refrigerator’s water system, so filtration is handled by the refrigerator water filter (not a separate “ice maker-only” filter). For the exact filter location and replacement steps, use the LFC21770ST owner's manual.

How the ice maker is filtered

In most LG bottom-mount refrigerators, water flows through the refrigerator’s water filter first, then feeds the ice maker and any water dispenser. That means:

• If the filter is clogged, ice production can slow down or stop.
• If the filter is overdue, ice can taste or smell off.
• If you bypass the filter, ice quality depends on your home water.

When to replace the water filter

A common replacement interval is about every 6 months, or sooner if you notice reduced flow or taste/odor changes.

• Replace sooner if you have heavy ice use.
• Replace sooner if you have hard water or sediment.
• Replace after long periods without use (stale water).
• Replace if ice cubes are hollow or smaller than normal.

Symptom	Most likely cause	What to do
Slow ice production	Restricted water flow	Replace the filter; confirm supply valve is fully open
Bad-tasting ice	Old filter or odors in freezer	Replace the filter; clean bin; store food sealed
No ice at all	No water to ice maker	Check shutoff arm/settings; inspect the refrigerator water inlet valve 5220JB2010A

Why it matters

The ice maker is very sensitive to water flow and water quality. Keeping the filter current helps prevent low ice output, cloudy cubes, and mineral buildup that can shorten the life of the ice maker.

Related DIY help

• How to replace the water filter in an LG refrigerator

Last updated: January 2026

For LG refrigerators like model LFC21770ST, the most common customer-reported issue is cooling trouble (warm fridge or freezer), usually tied to the sealed cooling system or airflow/defrost problems. Ice maker issues and water leaks are also frequent and often easier to diagnose and repair. See the LFC21770ST owner's manual for model-specific operating checks and temperature settings.

Most common issues we see (and what they look like)

• Not cooling or weak cooling: food softening, freezer thawing, compressor running a lot
• Temperature swings: fridge too warm but freezer OK (or the reverse)
• Ice maker not making ice: no ice, small cubes, or slow production
• Water leaks/puddles: water under crisper drawers or on the floor
• Door not sealing well: moisture, frost, or warm spots near the door edge

Quick checks before replacing parts

• Confirm controls are set to typical targets: 37°F fresh food and 0°F freezer.
• Make sure vents inside the compartments are not blocked by food packages.
• Listen for the evaporator fan; if it is silent when the door is closed, airflow can drop.
• Check door closure: a weak seal can mimic cooling problems.
• If you see water inside the refrigerator, inspect the drain path for clogs.

Common symptoms and likely causes (at-a-glance)

Symptom	Common cause area	Parts often involved
Warm fridge and freezer	Sealed system or compressor/start components	Compressor, start relay
Freezer cold, fridge warm	Airflow/evaporator fan or damper/ducting	Fan motor, fan blade
Frost buildup, poor cooling	Defrost system issue	Defrost heater
No ice	Ice maker or water supply/valve	Ice maker, inlet valve
Water under drawers	Defrost drain restriction	Drain tube

Parts that match these problems on LFC21770ST

• If the ice maker is the issue, start with the ice maker kit AEQ72909603.
• If you have puddles or water inside, the refrigerator drain tube 5251JA3003D is a common fix path.
• If airflow is weak or noisy, check the LG refrigerator evaporator fan motor 4681JB1027C and the refrigerator evaporator fan blade 5901JA1021A.
• If ice or water dispensing is inconsistent, the refrigerator water inlet valve 5220JB2010A is a frequent suspect.

Why it matters

Cooling problems can spoil food quickly, and airflow or defrost issues can look like a major failure even when the fix is a fan, heater, or drain-related repair. Starting with symptom-based checks helps avoid replacing the wrong part.

Last updated: January 2026