Bottom Line Up Front (The Thermal Overload Trip)
An LG refrigerator linear compressor clicking noise followed by a complete loss of cooling means the compressor is drawing excessive current and tripping the thermal overload protector.
The Hard Truth: In many cases, this clicking indicates a serious internal mechanical failure of the linear piston. However, before condemning the fridge, you must rule out a shorted PTC start relay or a blown capacitor bank box — both of which are inexpensive fixes.
Table of Contents
Hearing a loud, metallic clicking noise every 2 to 3 minutes from the back of your LG fridge is a major red flag. This noise happens when the main inverter PCB attempts to pump voltage into the compressor, but an internal electrical short or mechanical jam spikes the current. This triggers the tiny bimetal overload disc to snap open with a distinct “click” to prevent a kitchen fire, leaving your freezer and fresh food cabins to warm up rapidly.
As an electrical engineer with 8 years of hands-on appliance diagnostics experience, I’ve seen homeowners panic and junk their refrigerators when the issue was a simple $15 external start component. Conversely, generic advice often tells you to just “clean the coils” when the linear drive piston has actually seized completely.
Based on common failure patterns seen across appliance repair communities and technician forums, the verdict is consistent: you should perform an electrical resistance test at the compressor terminals before calling for a factory warranty overhaul.
Required Field Tools and OEM Parts Matrix
Testing Gear: [AstroAI Digital Multimeter AM33D on Amazon]
- Specification: Measuring terminal loop resistance to verify motor windings.
- Difficulty: Intermediate
Replacement Part: [Universal Refrigerator Overload Relay Combination Kit on Amazon]
- Specification: Generic 3-in-1 or single-pin PTC starter block used to bypass external electrical faults. Confirm compatibility with your exact compressor model before purchasing.
- Difficulty: Beginner
Hand Tools: [Channellock 1/4-Inch Nut Driver on Amazon]
- Specification: Removing the lower rear galvanized sheet metal access panel shroud.
- Difficulty: Beginner
1. The Corporate Service Manual vs. Reddit Reality Grid
Before calling for an expensive factory service appointment, look at the contrast between what corporate user manuals claim versus what the Reddit appliance repair community and field-level diagnostics often reveal:
| Official LG Manual Advice | The Real Reddit Community Tech Hack | Required Tools & Material Specs |
|---|---|---|
| Clean the condenser coils and ensure proper airflow clearances around the cabinet shroud. | This only resolves the issue in a minority of cases. If the unit is already clicking, the thermal overload is tripping on electrical current spikes, not ambient room heat. | [AstroAI Digital Multimeter AM33D on Amazon] |
| Replace the entire compressor assembly if it fails to start during diagnostics. | Perform the Rattle Test first. Pull the black PTC starter box off the side of the compressor shell and shake it. If it rattles like loose sand, the internal ceramic disc is shattered — a much cheaper fix. | Universal 1-Pin PTC Relay Module |
| Contact LG customer support to schedule an authorized sealed-system field technician. | Check your serial tag first. LG has faced class-action litigation over linear compressor failures, and many affected models qualify for extended warranty coverage on compressor parts (and in some cases, labor). | Smartphone Camera (For Serial Number) |
How to Troubleshoot the Compressor Clicking Noise Step-by-Step
[Visual Checkpoint: Watch the 01:15 mark of the embedded video below to see exactly how to unsnap the black plastic starter shield box from an LG linear compressor shell]
Step 1: Execute the Reddit-Approved “Rattle Test” on the PTC Starter
Before digging into complex inverter electronics, you must rule out the modular starter block attached to the compressor terminals. If the ceramic disk inside this block fractures, it creates an instant electrical dead short.
- Step 1.1: Disconnect the primary 3-prong electrical grounding wall plug from the kitchen line socket.
- Step 1.2: Pull the refrigerator away from the wall enclosure cutout and unscrew the lower back metal panel.
- Step 1.3: Locate the small black square plastic box snapped directly onto the side copper pins of the large black compressor tank.
- Step 1.4: Use a flathead screwdriver or putty knife to gently pry the wire retaining clip down and pull the box straight off the pins.
- Step 1.5 — The Rattle Test: Hold the black starter box right next to your ear and shake it vigorously. If you hear a distinct rattling sound like broken glass or pebbles, the internal ceramic switch has disintegrated. Replace it with a matching replacement start relay to silence the clicking noise immediately.
Step 2: Read Compressor Pin Resistance to Diagnose Motor Seizure
If the starter block is silent and solid, use your multimeter to check the internal health of the linear compressor’s primary motor coil system.
- Step 2.1: Keep the refrigerator completely unplugged from the wall line. Never test resistance on a live circuit.
- Step 2.2: Adjust your digital multimeter dial interface to the Lowest Ohms (Ω) setting scale.
- Step 2.3: Look at the side of the compressor where you pulled the starter box off. You will see copper pins arranged in a triangle.
- Step 2.4: Touch your multimeter probes across the terminal pins to check the winding resistance.
- Step 2.5: On a healthy standard compressor, you measure resistance between all three pin combinations (Common to Start, Common to Run). On an LG linear inverter compressor specifically, healthy winding resistance typically falls in a low single-digit to low double-digit ohm range — but the exact figure varies by model (some models read closer to 3–7Ω, others closer to 7–9Ω). Always cross-check the exact expected value against your specific model’s service manual rather than relying on a single universal number.
- Step 2.6: If your multimeter displays 0.00 (direct short) or OL (open line), or if you touch one probe to a pin and the other to the bare copper pipe and get continuity (grounded motor), the compressor is internally dead. The internal linear spring or piston has likely broken, and the entire unit will need to be swapped by a certified sealed-system professional.
Community Horror Stories: The “Hard Start Kit” Disaster
⚠️ CRITICAL WARNING FROM THE REPAIR FORUMS: A dangerous DIY trend circulating on Reddit’s r/appliancerepair and various YouTube channels involves installing an aftermarket “Hard Start Kit” (like an HS600 or Supco 3-in-1 bullet capacitor) onto an LG fridge to force a clicking compressor to kick over.
As an electrical engineer with hands-on appliance diagnostics experience, I’d heavily warn against this. Standard old-school refrigerators use rotational compressors that can sometimes be forced loose with a hard start capacitor spike. But LG linear compressors are an entirely different inverter-driven digital platform. Forcing a large 120V AC voltage spike from a hard start kit directly into a linear inverter motor can destroy the delicate microchips on your main Inverter Power Board module almost instantly. It turns a compressor issue into a serious electrical fire hazard, and can damage the front door display screen in the process. Stick strictly to low-voltage multimeter diagnostics.
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FAQ: Frequently Asked Questions
Why does the clicking sound on my LG fridge only happen every 3 to 5 minutes?
The 3-to-5 minute interval is roughly the time it takes for the bimetal thermal overload protector disc to cool down. When the compressor fails to start, it draws excessive current, heating up the overload switch until it clicks “open” to cut power. After a few minutes of sitting idle, the metal disc cools down, snaps back “closed” with another click, and attempts to start the compressor again — creating a repeating clicking failure loop.
Is it true that LG covers these clicking compressors under a special warranty?
Yes. LG has faced multiple class-action lawsuits over premature linear compressor failures, and settlements have extended compressor parts warranty coverage to 10 years from the original purchase date for many affected models, with some more recent settlements also covering labor for a period of years. Coverage terms vary by model and purchase date, so check your specific model against LG’s official warranty/settlement information using your serial number before assuming full coverage.
Additional Resources
For further troubleshooting support, verify your exact model’s expected resistance values using LG’s official service manual or an authorized parts retailer, and search r/appliancerepair on Reddit for other homeowners who have posted about linear compressor clicking issues on similar LG models.
Note: This guide is based on general appliance-repair troubleshooting logic for linear compressor failures. Always confirm exact specifications, part numbers, and warranty eligibility against your refrigerator’s specific model number and serial tag before ordering parts or filing a warranty claim.
Hi, I’m Pranjul — the person behind this website.
I hold a Diploma and B.Tech in Electrical Engineering, along with hands-on training through ITI. For over 3 years, I worked as an ITI College Instructor, teaching electrical fundamentals and practical skills to hundreds of students.
Through that experience, I noticed something: most electrical troubleshooting information online is either too technical for everyday homeowners, or too vague to actually solve real problems. That’s the gap this website aims to fill.