The compressor is the “heart” of the refrigerator, and its breakdown means not just inconvenience, but the risk of losing all the food in a matter of hours. However, not every malfunction requires calling a technician: more than 60% of problems with the compressor you can diagnose it yourself, having a multimeter, a screwdriver and 20 minutes of time on hand. In this article we will look at how to check the functionality of a refrigerator compressor at home - from visual inspection to electrical circuit tests - and also provide video instructions for clarity. video instructions for clarity.
It is important to understand: the compressor can fail both due to natural wear and tear (average service life is 10–15 years) and due to the fault of the user. For example, Atlant refrigerators and "Indesit" often suffer from compressor overheating due to improper installation (close to the wall) or condenser grille clogged with dust. And models with a system No Frost (for example, Samsung RB30J3000WW or LG GA-B409SLGL) may be “silent” due to a faulty start-up relay, which is mistakenly mistaken for a breakdown of the compressor itself.
Before you take up the tools, answer two questions: 1. Does the refrigerator turn on, but does not freeze - or does not turn on at all? 2. Are relay clicks heard when you try to start?
From The answers depend on the verification algorithm. Next, we will analyze both scenarios, and also show how to distinguish a compressor malfunction from a thermostat failure or freon leak without special equipment.
Signs of a compressor malfunction: when it’s time to sound the alarm
The first signal of problems with the compressor is a change in the operation of the refrigerator. However, many users confuse the symptoms of compressor failure with malfunctions of other components. For example, if a refrigerator Samsung RL34ECMS or Bosch KGN39XL30R stops freezing, but the motor is humming, it may not be the compressor that is to blame, but a refrigerant leak or a clogged capillary tube.
Pay attention to these 5 key signs, which directly indicate compressor:
- 🔊 The refrigerator does not turn on at all - no sounds of the motor, no indicators are on (or they are on, but the compressor is silent).
- ⚡ The compressor tries to start, but immediately turns off (relay clicks are heard, but the motor does not pick up speed).
- ❄️ The freezer does not cool, and the compressor housing heats up excessively (more than 70°C).
- ⏳ The motor runs non-stop (more than 20-30 minutes in a row), but the temperature in the chambers does not drop.
- 💥 The appearance of sparks or a burning smell from the back of the refrigerator (a critical sign - requires immediate shutdown!).
If you observe at least one of these symptoms, it’s time to move on to diagnosis. But first, make sure that the problem is not power: check the socket, plug and power cord. For electronically controlled refrigerators (for example Liebherr CBPesf 4055), it is also worth resetting the settings by turning off the power for 5-10 minutes.
Preparation for testing: tools and safety measures
To diagnose the compressor at home, you will need:
- 🔧 Phillips and flathead screwdrivers (to remove the protective casing).
- 📊 Multimeter (to check winding resistance and voltage).
- 🔍 Flashlight (inspection of contacts and relays).
- 🧤 Rubber gloves (protection against accidental electric shock).
- 📱 Smartphone (for filming the process or finding the connection diagram for your model).
Important! Before starting work unplug the refrigerator and wait until the capacitor is discharged (10–15 minutes). The compressor is under high pressure, and the contacts of the start-up relay are under voltage of 220V. Do not touch the refrigerant pipes: they may be hot (up to 90°C) or frostbitten (up to –30°C).
⚠️ Attention: If your refrigerator is a model with inverter compressor (for example, LG GA-B489YVQZ or Samsung RB37J5230SA), do not disassemble it yourself! These devices have complex electronic components, and incorrect diagnosis can lead to damage to the control board. Contact the service center.
Also prepare your work space: 1. Move the refrigerator away from the wall (at least 50 cm). 2. Remove all food from the freezer (if the check takes more than 30 minutes). 3. Put cardboard or a rag under the legs of the refrigerator - condensation may fall out when removing the casing.
☑️ Preparing for compressor diagnostics
Visual inspection of the compressor: what can be seen without instruments
Start with an external inspection of the compressor. It is located at the bottom of the refrigerator, under a protective metal casing. In most models (for example, Biryusa 130 or Nord NRB 105W), the casing is secured with 4–6 screws. Carefully remove it, remembering the location of the wires.
Pay attention to the following details:
| Element | Normal condition | Signs malfunctions |
|---|---|---|
| Compressor housing | Clean, free of rust, evenly heats up to 50–60°C | Traces of oil, melted areas, excessive heating (more than 70°C) |
| Start-protective relay | Fits tightly, no cracks, contacts are not oxidized | Burnt contacts, cracks on the body, burning smell |
| Refrigerant pipes | Clean, without ice and condensation, uniform color | Freezing, rust, traces of oil (indicates a freon leak) |
| Condenser (grid) | Clean, without dust, uniformly warm | Clogged with dust, cold or too hot in certain areas |
If you find traces of oil on the compressor housing or tubes, this may indicate depressurization of the system - Freon refilling will be required. A melted relay contacts often means that it is “stuck” and does not turn off the compressor, which leads to overheating.
Also check integrity of the wires, going to the compressor. In long-life refrigerators (10+ years), the insulation may crack, causing a short circuit. If the wires are damaged, they need to be replaced to check the compressor with a multimeter.
What to do if the compressor is covered with ice?
If the compressor housing or the tubes are covered with frost or ice, this indicates a freon leak or a clogged capillary tube. In this case, independent repair is impossible - a specialist with equipment for vacuuming and filling the system is required.
Checking the compressor with a multimeter: step-by-step instructions
If a visual inspection does not reveal obvious defects, proceed to checking the electrical circuits. To do this, you will need a multimeter in resistance measurement mode (ohmmeter). Action algorithm:
Step 1. Disconnect the compressor from the circuit.
Remove the start-up relay (it is attached to the compressor with latches or screws). Carefully disconnect the wires leading to the compressor contacts. Remember or photograph their location! Typical connection diagram:
Common (C) → Starting winding (S) → Working winding (R).
Step 2. Check the resistance of the windings.
Switch the multimeter to resistance measurement mode (200 Ohm range). Touch the contacts with the probes:
1.C → S (starting winding) - norm: 20-40 Ohm.
2. C → R (working winding) - norm: 10-20 Ohm.
3. S → R - norm: sum of resistances C→S and C→R (30–60 Ohm).
If the device shows: 0 Ohm —short circuit in the winding. ∞ (infinity) —open circuit.
Both cases mean that the compressor is faulty and requires replacement.
Step 3. Check the resistance to the case.
Switch the multimeter to the maximum range (2000 kOhm or 2 MOhm). Touch each contact in turn with one probe (C, S, R), and with the second one touch the metal body of the compressor. Normal: the resistance should tend to infinity (∞). If the device shows any value (even 500 kOhm), this means breakdown to the housing the compressor is dangerous to operate!
⚠️ Attention: In refrigerators with inverter compressors (for example, Panasonic NR-BN30AW1) resistance test may give false results due to built-in electronics. To diagnose such models, you need an oscilloscope or contact the service.
If all three tests (C→S, C→R, S→R) showed normal values, and there is no resistance to the case, the compressor electrically sound. The problem may lie in the start-up relay, thermostat or freon leak.
Checking the start-up relay: why the compressor does not start
In 40% of cases of “compressor failure,” it is not the device itself that is to blame, but start-up protection relay. It is responsible for starting the engine and protecting it from overheating. If the relay is faulty, the compressor will either not turn on at all or will turn off after a few seconds.
How to check the relay: 1. Remove the relay from the compressor (it is secured with latches or screws). 2. Look at the contacts: if they burnt or oxidized, the relay needs to be replaced. 3. Check the relay circuit with a multimeter in dial mode:
- Between contacts L i T (in the normal state the circuit is open).
- When shaking the relay, a click should be heard and the circuit should close briefly.
If the relay does not click or the circuit does not close, it must be replaced. For most refrigerators (Atlant, "Stinol", "Indesit"), universal relays of type RTK-X or RTP-1are suitable. Cost - from 300 to 800 rubles.
Also check thermostat (if it is in your model). To do this: 1. Find the thermostat (usually located inside the refrigerator compartment, behind a plastic panel). 2. Remove the terminals from it and short them together (with a wire jumper). 3. Plug in the refrigerator. If the compressor starts working, the thermostat is faulty.
Video instructions: how to check the compressor using the example of popular models
For clarity, we have selected a video with step-by-step diagnostics of the compressor on refrigerators of different brands. Please note: the testing algorithm is the same for most models, but the location of the relay and compressor may differ.
1. Refrigerators “Atlant” and “Biryusa” (classic compressors):
In these models, the compressor and relay are located openly, without additional casings. The video shows how to ring the windings and check the relay:
YouTube: “Diagnostics of the Atlant MU 1801-000 refrigerator compressor”
2. Refrigerators “Indesit” and “Ariston” (with a bottom-mounted compressor):
Feature - the compressor is covered with a plastic casing. The video shows how to remove it and check it with a multimeter:
YouTube: “Repairing the Indesit BIA 18 refrigerator”
3. Samsung and LG refrigerators (inverter compressors):
Inverter models require caution! The video demonstrates how to check only external circuits (relay, thermostat) without disassembling the compressor:
YouTube: “Diagnostics of the LG GA-B409 inverter compressor”
4. “Nord” and “Snaige” refrigerators (with No Frost system):
In these models, the compressor often “suffers” from overheating due to a clogged condenser. The video shows how to clean the grill and check the motor:
YouTube: “Repairing the Nord NRB 137W refrigerator - checking the compressor”
If you did not find a video for your model, look for videos by request:
[Refrigerator brand] + "checking the compressor multimeter".
Pay attention to the publication date - current videos are no older than 2-3 years.
What to do if the compressor is faulty: repair or replacement?
If diagnostics show that the compressor is faulty, you have three options:
- 🔧 Independent replacement — suitable for models with classic compressors (for example Atlant, "Stinol"). The cost of a new compressor is from 3,000 to 8,000 rubles, plus 1,000–1,500 rubles for freon and refilling.
- 👨🔧 Calling a technician - optimal for refrigerators with inverter compressors or system No Frost. The average cost of work is 2,500–5,000 rubles (excluding spare parts).
- ♻️ Purchasing a new refrigerator is rational if your model is older than 10 years or repairs will cost more than 50% of its cost.
To replace the compressor yourself, you will need: 1. Buy a similar compressor (the parameters are indicated on the nameplate of the old one). 2. A vacuum pump (for pumping out old freon). 3. A refrigerant cylinder (the type of freon is indicated on refrigerator nameplate). 4. Blowtorch and solder (for sealing tubes).
Step-by-step replacement algorithm: 1. Pump out the freon from the system (use a vacuum pump). 2. Unsolder the tubes from the old compressor. 3. Install a new one compressor, connect the tubes and fill them with freon. 4. Solder the joints and check the system for leaks (with soap solution). 5. Connect the electrical contacts and start the refrigerator.
⚠️ Attention: Refilling freon requires a certificate and special equipment. In Russia, self-refilling with refrigerant prohibited by law (Federal Law No. 99 “On licensing of certain types of activities”). For violation, a fine of up to 50,000 rubles is provided. If you do not have a license, entrust the refueling to a professional.
If you decide to call a specialist, check with him: 1. Work guarantee (minimum 6 months). 2. The cost of diagnostics (in some services it is free if you agree to repair). 3. Spare parts used (original or analogues).
FAQ: Frequently asked questions about checking the refrigerator compressor
Is it possible to check the compressor without removing it from refrigerator?
Yes, but only partially. You can:
1. Listen to the operation of the motor (a uniform hum is normal, rattling or knocking is a breakdown).
2. Check the voltage at the relay contacts (should be 220V when turned on).
3. Measure the temperature of the compressor housing (more than 70°C - overheating).
However, for accurate diagnostics (checking the windings, resistance to the housing), the compressor must be turned off.
How to distinguish a compressor malfunction from a freon leak?
If there is a freon leak, the compressor works without stopping, but the refrigerator does not freeze. The compressor housing remains cold or slightly warm. If the compressor does not turn on at all or turns off after a few seconds, the problem is in it itself or in the relay.
Also, if there is a freon leak on the tubes, you can see oil stains (the refrigerant carries away the oil from the compressor).
How much does it cost to replace a compressor during service?
The cost depends on the refrigerator model and region:
1. Classic compressors (for example, Atlant, "Biryusa") - 3,500–6,000 rubles (with freon refilling).
2. Inverter compressors (for example, Samsung», «LG») - 6,000–12 000 rubles.
3. Premium class refrigerators (Liebherr», «Miele») - from 10,000 rubles.
The price includes: a new compressor, work of a master, refilling freon and diagnostics.
Can it be turned on? a refrigerator with a faulty compressor “for a while”?
Absolutely not! If the compressor is faulty (for example, a breakdown in the housing or a short circuit in the winding), its operation can lead to:
1. Fire (due to overheating of the windings).
2. Electric shock (during breakdown on the housing).
3. Failure of other components (for example, control board).
If the refrigerator does not freeze, but the compressor is working, you can temporarily use it in the “maximum freezing” mode, but not longer than 1-2 days.
How to extend the life of a refrigerator compressor?
Follow these rules:
1. Regularly (once every 6 months) clean the condenser (grid on the back wall) from dust.
2. Do not place the refrigerator close to the wall (minimum gap - 5 cm).
3. Do not overload the freezer (optimal load is 70–80% of the volume).
4. Monitor the room temperature (optimally 18–22°C).
5. Defrost the refrigerator with the system No Frost once a year (despite automatic defrosting).