How to check the compressor of an LG refrigerator yourself: 5 working methods

The compressor is the “heart” of the refrigerator LGon which not only cooling, but also the durability of the equipment depends. If your refrigerator suddenly stops freezing, makes strange noises, or runs nonstop, the problem may lie with the compressor. However, do not rush to call a specialist: most faults can be diagnosed independentlyhaving a minimal set of tools at hand.

In this article we will analyze 5 proven ways to check the compressor from visual inspection to testing with a multimeter. You will learn how to distinguish a compressor breakdown from a thermostat malfunction or a freon leak, and also when to sound the alarm and contact a service center. All methods are adapted for models LG with inverter and linear compressors (series GA-B419*, GR-B429*, GB-B399* and others).

Before starting diagnostics, make sure that the refrigerator is disconnected from the network. This is not only a matter of safety, but also the accuracy of measurements: some tests require completely de-energizing the equipment for 10-15 minutes.

1. Visual inspection of the compressor: what can be noticed without tools

Start with an external inspection of the compressor compartment. In most models LG it is located in the lower part of the rear wall (the exception is some models LG Door-in-Doorwhere the compressor can be hidden under a decorative panel). Remove the back cover by unscrewing 4-6 screws with a Phillips screwdriver.

Pay attention to the following details:

• 🔥 Case overheating. If the compressor is too hot (cannot hold your hand for more than 2-3 seconds), this may indicate an overload or inter-turn short circuit in the windings. Normal temperature is up to 60–70°C during active operation.
• 💧 Oil stains. Oil leaks on the body or pipes indicate depressurization of the system. In this case, you will need to refill freon and check the seals.
• ⚡ Oxidation of contacts. Green or white coating on the terminals of a relay or starting capacitor is a sign of poor contact, which can cause malfunctions.
• 🔊 Foreign objects. Sometimes dust, cobwebs, or debris will accumulate near the compressor and block the vents. This leads to overheating.

If you find black spots or melted areas on the compressor bodythis is a critical sign - further operation of the refrigerator is dangerous! Immediately unplug it and do not turn it on until the part is replaced.

⚠️ Attention: Do not touch the refrigerant pipes with your bare hands - if a leak occurs, freon can cause frostbite to the skin. Use gloves.

2. Sound check: what do hums, clicks and silence mean

Sound diagnostics are one of the easiest ways to identify problems with a compressor. Plug in the refrigerator and listen to its operation. Normal sounds for medium tonality (for inverter models - almost silent). data-i="83">during the circulation of freon (especially noticeable in the first minutes after switching on). LG:

• 🔄 Steady hum medium tone (for inverter models - almost silent).
• 🔊 Brief click at startup (start relay activation).
• 💨 Slight hissing when circulating freon (especially noticeable in the first minutes after switching on).

And now - alarm signals:

If the refrigerator LG with an inverter compressor (series GA-B419, GR-B429) began to operate louder than usual, this may be due to system overload due to:

• 🌡️ A sharp increase in room temperature (for example, in summer).
• 🧊 Loading a large amount of warm products.
• 🔌 Voltage surges in the network (inverter compressors are sensitive to differences).

3. Multimeter test: how to ring the compressor windings

For in-depth diagnostics, you will need a multimeter (even a budget model with a resistance measurement function will do). Before starting the test:

1. Disconnect the refrigerator from the network and discharge the capacitor (short-circuit it with a screwdriver with an insulated handle).
2. Remove the starting relay (it is attached to the compressor with 1-2 screws or latches).
3. Disconnect the wires from the terminals compressor (take a photo of their location so as not to be confused during reassembly!).

On the compressor body you will see three terminals marked with letters:

• S (Start) - starting winding.
• R (Run) - working winding.
• C (Common) - common output.

Ring the resistance between pairs of terminals:

If the multimeter shows:

• 🔢 0 Ohm (short circuit) - the compressor is faulty, replacement is required.
• 🔢 ∞ (infinity) — winding breakage, cannot be repaired.
• 🔢 The values are very different from the norm — interturn breakdown is possible (the compressor will heat up and start poorly).

⚠️ Attention: In inverter compressors LG the winding resistance may be lower (10–25 Ohms). Check the data for your model in the technical data sheet.

Disconnect the refrigerator from the mains|Discharge the capacitor|Remove the starting relay|Disconnect the wires from the terminals|Write down the location of the wires-->

4. Checking the starting relay and capacitor

If the compressor does not start, but the windings are ringing normally, the problem may lie in starting relay or capacitor. These parts are responsible for the initial push of the rotor and protection against overloads.

How to check the relay:

1. Remove the relay from the compressor (usually it is attached with clips or one screw).
2. Shake the part - if you hear a knock inside or the core rattles, the relay is faulty.
3. Ring the relay contacts with a multimeter in circuit test mode. When the relay is turned over, a click should be heard and the circuit should close/open.

Diagnostics of the capacitor:

• 🔋 Disconnect the capacitor from the circuit (it is located next to the relay).
• 🔍 Inspect it for swelling or electrolyte leaks.
• 📊 Measure the capacitance with a multimeter with the appropriate function. A deviation from the nominal value (indicated on the case) by more than 20% is a sign of malfunction.

For models LG with inverter compressors (GA-B419, GB-B399 series), capacitors with a capacitance 15–25 μFare often used. If your refrigerator belongs to the LG InstaViewline, also check control board - it may block the start of the compressor due to sensor errors.

How to distinguish a relay malfunction from a problem with the compressor?

If you hear a click when you turn on the refrigerator, but the compressor does not start, and after 5-10 seconds the click is heard again, the relay is to blame. If there are no clicks at all, the problem may be in the compressor windings or lack of power.

5. Temperature test: checking the performance of the compressor

If the compressor starts, but the refrigerator does not freeze well, it will help to evaluate its performance temperature test. You will need a thermometer (preferably infrared) and 10–12 hours of time.

Testing algorithm:

1. Set the temperature regulator to the average value (for example, +4°C for a fridge compartment).
2. Place the thermometer in the center of the chamber (next to the temperature sensor).
3. Close the door and do not open it for 6-8 hours.
4. After the specified time, check the temperature:
   • 🥶 Below +2°C —the compressor is working too intensely (there may be problems with the thermostat or freon leak).
   • ❄️ +2°C to +6°C —normal mode.
   • 🌡️ Above +6°C —the compressor cannot cope (weak compression, system clogged).

For models LG with the system Smart Diagnosis (for example, GR-B429SL), you can use the built-in diagnostics:

1. Press and hold button Ice Plus (or Freezer) for 5 seconds.
2. Wait for the sound signal - the refrigerator will display an error code by flashing the indicators.
3. Check the code with the table in the instructions (for example, E1 - problem with sensor E4 - compressor malfunction).

⚠️ Attention: If the refrigerator LG with the system No Frost begins to become covered with frost on the back wall, this may indicate loss of compressor performance or a freon leak. Do not try to defrost it manually - this is a temporary measure.

6. When to call a technician: signs of serious damage

Not all compressor malfunctions can be repaired yourself. Contact the service center LGif:

• 🔥 Compressor smoke or emits a burning smell - this indicates a short circuit inside the housing.
• ⚡ On compressor terminals no voltage, but there is power on the control board.
• 💧 From the refrigerant tubes drips oil - a sign of depressurization of the system.
• 🔄 Refrigerator turns on for 1-2 seconds and turns off (overload protection is activated).
• 📉 Temperature in the chamber rises above +15°C, despite the continuous operation of the compressor.

The cost of compressor repair LG depends on the type of failure:

Type of repair	Average cost (2026)	Completion time
Replacement of starting relay	1 500–2 500 ₽	1–2 hours
Replacement of capacitor	1 200–2 000 ₽	1 hour
Replacing the compressor (without refilling)	8 000–15 000 ₽	3–5 hours
Refilling freon + eliminating leaks	5 000–10 000 ₽	4–6 hours

For refrigerators LG under warranty (usually 2-5 years for a compressor), repairs are free, but only if the breakdown is not caused improper operation (for example, power surges or mechanical damage). Before the technician’s visit, check:

• 📄 Availability of a warranty card and receipt.
• 🔌 Condition of the socket and network cable (are there any melts).
• 📡 No traces of self-repair (this will void the warranty).

⚠️ Attention: Parts for refrigerators LG (especially inverter compressors) are often supplied to order. The repair period may increase to 2-3 weeks.

FAQ: Frequently asked questions about LG refrigerator compressors

🔍 How to understand that the compressor has burned out and not just overheated?

Burnt The compressor usually does not start at all (no hum, no clicks), and its housing may be melted or blackened. An overheated compressor will work intermittently: it will turn on for a short time and turn off (thermal protection is triggered). Also, if the winding is burned out, the multimeter will show an open circuit (∞) or a short circuit (0 Ohm).

⚡ Is it possible to turn on an LG refrigerator without a start relay?

No, it's dangerous! The start relay not only starts the compressor, but also protects it from overloads. Without a relay, the windings can burn out in a matter of minutes. If the relay is faulty, replace it with a similar one (for LG relays RL3-1, RL4-1 or original LG 6871JB1006A).

🌡️ Why does the LG inverter compressor work without stopping?

Inverter compressors (GA-B419, GR-B429 series) designed to run longer than linear ones, but continuous operation may indicate:

• Freon leak (refill required).
• Temperature sensor malfunction (check error codes).
• Capillary tube clogged (need cleaning).
• The room temperature is too high (the norm for inverters is up to +32°C).

If the compressor does not turn off for more than 24 hours, call a specialist.

🔧 How often do you need to service the LG refrigerator compressor?

The compressor does not require regular maintenance, but once every 1-2 years it is recommended:

• Clean the back wall of the refrigerator from dust (with a vacuum cleaner or brush).
• Check the condition of the power cable and socket.
• Monitor the temperature in the room (optimally +18°C to +25°C).

For models with Smart Diagnosis (LG InstaView, Door-in-Doorit is useful to run self-diagnosis every six months (button Ice Plus + hold for 5 seconds).

💰 Is it worth repairing the compressor in an older refrigerator 10 years?
It is economically feasible to repair the compressor if:
• The refrigerator is in good condition (no rust, seals are in working order).
• The cost of repair does not exceed 30-40% of the price of a new refrigerator.
• The model is rare or with unique functions (for example, LG InstaView Door-in-Door).

For budget models older than 10 years (LG GA-B399, GR-349) it is often more profitable to buy a new refrigerator - modern inverter compressors are 30-50% more energy efficient.