How to Fix LG Microwave Error COOL

Written by

⚠️ Safety Warning: Appliance repair involves electricity, gas, and moving parts. Always disconnect power before working on any appliance.

Error Code: COOL Difficulty: Easy

Problem: The microwave is in a cooling cycle. The fan will run until the oven’s temperature drops.

⚖️ Repair Decision

⚠️ CHECK WARRANTY / AGE

no_parts

How to Fix COOL Error (Step-by-Step)

This is a normal function; no action is required and confirm the error stays cleared during a full test cycle.
The microwave has completed a long cooking cycle and is running the fan to cool down its internal components.
Allow the cooling cycle to finish on its own. The ‘COOL’ message will disappear from the display.
Do not unplug the microwave or try to use it during this brief cooling period.
Once the fan stops and the display returns to the clock, the microwave is ready for use.
Turn the appliance off, wait about 2 minutes, then turn it back on.
Check for simple blockages (lint screen, drain path, or filter) and clean anything you find.

Recommended Parts to Check

Compatibility note: Exact LG microwave part numbers vary by complete model number, production revision, and internal layout. Treat these as diagnostic part-category searches, then confirm fit with the full model number before ordering.

Start here

LG microwave cooling fan

Common replacement category: Cooling fan

Symptom match: Most likely when: the COOL message appears after heating, airflow is weak, or the cabinet runs hot.

Check first: Check first: blocked vents, fan blade movement, and fan voltage only after safe disassembly.

Find compatible LG microwave cooling fan
Also check

LG microwave thermostat

Common replacement category: Thermostat or thermal cutout

Symptom match: Most likely when: the COOL message follows overheating or intermittent shutdowns.

Check first: Check first: continuity and mounting contact before replacing a temperature protection device.

Find compatible LG microwave thermostat
Sensor path

LG microwave temperature sensor

Common replacement category: Temperature sensor

Symptom match: Most likely when: the COOL message repeats even with clear airflow.

Check first: Check first: loose sensor wiring and connector corrosion.

Find compatible LG microwave temperature sensor
Control path

LG microwave control board

Common replacement category: Electronic control board

Symptom match: Most likely when: airflow and sensor checks pass but the COOL message stays.

Check first: Check first: harness seating and visible heat or moisture damage.

Find compatible LG microwave control board

Model-number note: Use the LG microwave model tag before buying; these links are not universal fit claims.

LG Microwave Error COOL Checks Before Replacing Parts

Disconnect power before opening the cabinet, and do not touch high-voltage parts unless you are trained to discharge and test them safely.
Confirm the full LG model number from the tag before matching any replacement category to the appliance.
Check the simple symptom path first: door closure, keypad response, airflow, and any obvious loose or damaged connectors.
Test switches, sensors, or harnesses with a meter where the service data supports it instead of ordering parts by code alone.
If the related parts test correctly, inspect the control area and harness before considering a model-matched control board.

When It’s Better to Replace Than Repair

Microwave repairs require extra caution because high-voltage parts can retain a dangerous charge after unplugging.
Door switches, turntable motors, fuses, and controls may be replaceable, but many microwave failures are safer and cheaper to solve with replacement.
For repair parts or built-in trim kits, verify exact fit with the full microwave model number before buying; these links are general replacement-appliance shopping options.