LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean F-4 Error Fix: Humidity Sensor Error

Humidity sensor for Sensor Cook/Reheat not reading correctly. Detects steam to determine doneness. Clean sensor if accessible. Replace if cleaning doesn't resolve. Timed cooking still works.

Low severity2 fixes available✨ Free fix available

Quick Answer

Error F-4 on the LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean means: Humidity Sensor Error. The top-ranked community fix is “Replace the Humidity Sensor Assembly” (medium difficulty, ~45 min, DIY cost: $15-$25). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · microwave

Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.

When to Call a Professional

While many microwave repairs can be done safely at home, consider hiring a qualified technician if:

The repair involves electrical wiring, gas lines, or refrigerant
You've tried the top-ranked fix and the error persists
You smell gas, see sparking, or notice water leaking
The repair requires specialized tools you don't have
Your appliance is still under manufacturer warranty

Average professional repair cost for this issue: $150-$220.

Other LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean Error Codes

DOOR SWITCH FAIL

Door Switch Failure

2 fixes

EXHAUST FAN NOISE

Exhaust Fan Motor Noise/Failure

2 fixes

F-1

Open Thermistor / Thermal Error

Shorted Thermistor

Touchpad Shorted Key

Control Board Error

Magnetron Failure

Sensor Error / Key Input Error

2 fixes

People Also Ask About LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean Error F-4

What does error code F-4 mean on a LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean?

Error code F-4 on the LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean means: Humidity Sensor Error. Humidity sensor for Sensor Cook/Reheat not reading correctly. Detects steam to determine doneness. Clean sensor if accessible. Replace if cleaning doesn't resolve. Timed cooking still works.

How do I fix error code F-4 on my LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean?

The most successful fix is "Replace the Humidity Sensor Assembly" (medium difficulty, ~45 minutes). Estimated DIY cost: $15-$25. HomeMD has 2 community-ranked fixes for this error.

Is error code F-4 on a LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean serious?

This error is rated low severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Can I fix LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean error F-4 myself?

Yes — the top-ranked community fix ("Replace the Humidity Sensor Assembly") is rated medium difficulty and takes about 45 minutes. Tools needed: T20 Torx screwdriver, Needle-nose pliers.

How much does it cost to repair LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean error F-4?

DIY cost: $15-$25. Professional repair typically costs $150-$220. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean have?

The LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean has 8 other known error codes, including: DOOR SWITCH FAIL (Door Switch Failure), EXHAUST FAN NOISE (Exhaust Fan Motor Noise/Failure), F-1 (Open Thermistor / Thermal Error), F-2 (Shorted Thermistor), F-3 (Touchpad Shorted Key), and 3 more.

What other error codes does the LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean have?

The LG LMHM2237ST 2.2 cu. ft. Over-the-Range Microwave with EasyClean has 8 other known error codes:

DOOR SWITCH FAIL — Door Switch Failure (2 fixes)
EXHAUST FAN NOISE — Exhaust Fan Motor Noise/Failure (2 fixes)
F-1 — Open Thermistor / Thermal Error (2 fixes)
F-2 — Shorted Thermistor (2 fixes)
F-3 — Touchpad Shorted Key (2 fixes)
F-5 — Control Board Error (2 fixes)
MAGNETRON FAIL — Magnetron Failure (2 fixes)
SE — Sensor Error / Key Input Error (2 fixes)

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