LG Range Hood SNR-ERR Error: Auto sensor failure (steam/smoke detection fault)
LG range hood SNR-ERR error — here is what every homeowner should know. LG range hood error — here’s what you need to know. The SNR-ERR error code on your LG range hood indicates auto sensor failure — the automatic cooking detection sensor is not responding to steam or smoke from the cooktop. This is […]
~45%
DIY Fixable
From $95
Typical Repair Cost
30 min–1.5 hours
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
Maybe. Manual fan operation is unaffected by SNR-ERR, so the hood can still be used on a manual setting. However, do not rely on Auto mode for ventilation safety while the sensor fault is present — activate the fan manually before cooking.
Can I reset the code?
Yes. A power-cycle reset after cleaning the sensor can restore Auto mode function when the cause is grease contamination. A persisting SNR-ERR after cleaning and resetting indicates a hardware failure that requires sensor replacement.
When to stop immediately?
Stop if you notice: Auto mode activates the fan constantly even when the cooktop has been cold for hours, SNR-ERR returns within minutes of every reset, even after cleaning.
Symptoms You May Notice
Fan does not activate automatically when cooking on the stovetop
Boiling water, high-heat frying, or heavy steaming does not trigger the Auto fan mode — the hood remains idle as steam and smoke build up in the kitchen, indicating the sensor is not detecting the cooking activity.
Auto mode activates the fan randomly with no cooking in progress
The fan switches on by itself at random intervals when the cooktop is not in use, suggesting the contaminated or degraded sensor is generating false-positive readings.
Auto mode indicator light is on but fan speed does not adjust to cooking intensity
The Auto mode appears to be active, but the fan runs at a fixed speed regardless of how much steam or smoke is produced, indicating the sensor input is not being processed correctly.
Inconsistent temperature performance
The range hood runs too hot, too cold, or cycles erratically because the control board receives inaccurate temperature readings from the faulty sensor.
Possible Causes
Grease or smoke residue coating the sensor
A film of accumulated grease and cooking smoke has coated the sensor element, blocking it from accurately detecting steam or particulate levels from the cooktop.
DIY PossibleDegraded or failed sensor element
The sensor's active element has worn beyond its usable detection threshold due to cumulative heat and contamination exposure and can no longer produce a reliable output signal.
Requires ProfessionalLoose sensor wiring or control board input failure
A loose connector between the sensor and the control board, or a failure in the PCB's sensor input circuit, is preventing valid sensor data from reaching the control logic.
Requires ProfessionalSafe Checks You Can Do
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1
Clean the sensor and surrounding area
Locate the sensor — typically a small probe or opening on the underside panel of the hood near the centre. With the unit off, gently wipe the sensor and its surroundings with a lightly dampened cloth to remove grease film, then dry thoroughly.
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2
Power-cycle the range hood
After cleaning, trip the circuit breaker for 30 seconds to reset the control board's sensor calibration, then restore power and test Auto mode with a pot of boiling water on the cooktop.
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3
Confirm correct Auto mode activation procedure
Check the owner's manual to verify the correct way to enable Auto mode on your specific model — on some LG range hoods, Auto mode must be activated by holding the fan button for 3 seconds, and is not the default on power-up.
When to Call a Professional
Contact a qualified technician if:
- Auto mode remains non-functional after thorough sensor cleaning and multiple power-cycle resets
- A confirmed replacement sensor does not restore Auto mode, indicating a control board fault
- Fan activates randomly at all hours with no cooking in progress, despite a clean sensor
Need Professional Help?
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