LG Refrigerator Error Er HM — What It Means & How to Fix It

What Does This Error Mean?

Er HM on an LG refrigerator stands for a Humidity Sensor fault. This code appears when the humidity sensor inside the fresh food compartment fails or reads outside acceptable parameters. The humidity sensor helps the refrigerator manage moisture levels to keep produce and fresh food in optimal condition. The main cooling system is not affected — your refrigerator and freezer will continue to maintain their temperatures normally. This is a low-urgency repair.

Affected Models

LG LRMVS3006S
LRFXS2503S
LG models with Smart Cooling Plus
LG InstaView models with air filtration and humidity management

Common Causes

The humidity sensor has degraded over time and is reading outside its acceptable range
Excessive condensation or moisture has built up on the sensor, causing a short circuit in the sensor element
The wiring connector to the humidity sensor has become loose or corroded
An air filter that is overdue for replacement is causing poor air circulation past the sensor
A firmware or software fault on the main board is misinterpreting the sensor data

How to Fix It

Check if your LG refrigerator has a fresh air filter (some models have one inside the fresh food compartment). If the filter is overdue for replacement, change it first. A clogged filter reduces air circulation and can affect sensor readings.

LG recommends replacing the fresh air filter every 6 months. The filter is typically located in the upper area of the fresh food compartment — it usually twists or snaps out.
Unplug the refrigerator for 60 seconds and plug it back in. This resets the control board and can clear a firmware-generated false Er HM.

If Er HM only appeared once or appears intermittently without other signs of trouble, a software glitch is the most likely cause. Monitor for a few days after the reset.
Open the fresh food compartment and look for any pooling of water or excessive condensation around the back wall or ceiling. Wipe the interior dry with a clean cloth. Excess moisture can reach the humidity sensor and trigger a fault.

Excessive condensation in the fresh food section often points to a worn door gasket. Press the gasket seal all the way around the door — if it feels loose or spongy, it may need to be replaced.
If your LG refrigerator is connected to the LG ThinQ app, open the app and check for available firmware updates for your model. LG periodically releases updates that fix sensor error codes including Er HM.

To update via ThinQ: open the app, tap your refrigerator, go to Settings or More > Check for Updates. Firmware updates download automatically when the fridge is connected to Wi-Fi.
If the error persists after the above steps, contact an LG-authorized technician. They will test the humidity sensor with diagnostic tools and replace it if necessary. Provide your model number and the specific error code Er HM.

The humidity sensor in LG refrigerators is an integrated component — not user-replaceable in most models. A technician is needed to remove the correct panel and swap the sensor safely.

When to Call a Professional

Er HM is a minor repair with no urgency. Humidity sensor replacement typically costs $60–$150 including labor. If a firmware update resolves the issue, there may be no parts cost at all. Contact LG at 1-800-243-0000 to check warranty and whether a known fix exists for your model.

Frequently Asked Questions

Is Er HM dangerous? Will my food spoil?

No — Er HM does not affect the main cooling system. Your refrigerator will stay at the correct temperature. The humidity sensor only manages moisture levels for optimal freshness. Food safety is not at risk. You may notice produce not staying fresh quite as long as usual, but there is no spoilage danger.

Can the LG ThinQ app help with Er HM?

Yes, for compatible models. The ThinQ app has a Smart Diagnosis feature that can send diagnostic data from your refrigerator directly to LG's service center. This can help determine whether Er HM is a sensor failure or a software issue. Open the ThinQ app, tap your refrigerator, and look for 'Smart Diagnosis' in the settings.

How often should I replace the air filter in my LG refrigerator?

LG recommends replacing the fresh air filter every 6 months. The filter removes odors and bacteria from the fresh food compartment air. A clogged filter does not directly cause Er HM, but poor air circulation past the humidity sensor can contribute to inaccurate readings. Replacement filters are available at LG's website and major appliance retailers for $10–$20.