How to check if the compressor is working in the refrigerator: a step-by-step guide with photos and videos

The compressor is the “heart” of the refrigerator, on which the cooling of the chambers and the safety of food depend. If the unit stops freezing, makes strange sounds or does not turn on at all, the first thought is that the compressor is broken. But before you call a technician or buy a new refrigerator, you should Check its performance yourself. In 60% of cases, the problem lies in small things: a faulty thermostat, a freon leak, or a clogged capillary tube.

Diagnostics of a compressor does not require professional skills - just basic tools (a multimeter, a screwdriver) and knowledge of the key signs of a malfunction are enough. In this article we will analyze 7 verification methodsfrom the simplest (visual inspection, listening to sounds) to advanced (testing windings, measuring resistance). You will also find out which symptoms accurately indicate compressor failureand when other components of the refrigerator are to blame.

⚠️ Attention: Working with the electrical circuits of the refrigerator requires compliance with safety precautions. Before any diagnostics be sure to disconnect the device from the network and discharge the capacitor (if you plan to remove the start relay cover). Do not touch open live contacts!

1. The first signs of a compressor malfunction: when to sound the alarm

A compressor breakdown rarely occurs suddenly - it is usually preceded by characteristic “symptoms”. If you notice them in time, you can avoid expensive repairs or loss of products.

The most obvious sign is the refrigerator does not cool. But this may also be due to other problems (freon leakage, thermostat malfunction). Pay attention to a set of signals:

• 🔊 Atypical sounds: the compressor hums, but does not start (protection is triggered), the relay clicks, knocking or grinding noises are heard. Normally, a working unit emits a uniform low-frequency hum.
• ⏱️ Cycles work/rest: if the compressor turns on for 5-10 seconds and immediately turns off, this is a sign interturn short circuit or a malfunction of the start relay.
• 🌡️ Overheating of the housing: touch the compressor (it is located at the bottom of the refrigerator at the back) - if it is hot even after 30+ minutes of inactivity, this indicates problems with the windings.
• 💡 There is light, but there is no cold: the light inside is on, but the motor does not start - there may be a malfunction in the compressor power circuit.

⚠️ Attention: If the refrigerator Indesit, Atlant or Samsung with the system No Frost it stopped freezing, but the fan in the freezer works - the problem may be compressor failure or a refrigerant leak. In models with a drip system (for example Biryusa, Stinol), if the compressor breaks down, frost does not form on the rear wall.

2. Visual inspection: what can be seen without tools

Before taking the multimeter, inspect the compressor and related elements. Many faults are visible to the naked eye.

Where is the compressor located? In 99% of refrigerators it is installed in the lower part of the rear wall, under a protective cover. In models Side-by-Side (for example, Samsung RL60) it can be located on the side.

• 🔧 Contact condition: remove the protective cover of the start relay (usually secured with 1-2 screws). If there are oxidation, burnt marks at the terminals of the compressor or relay, this is a sign of poor contact or voltage surges.
• 🧲 Oil on the body: dark oily spots under the compressor or on the tubes indicate about oil leakage from the crankcase. This is a critical failure - further operation will lead to jamming of the motor.
• ❄️ Icing of the tubes: if capillary tube (thin copper, going from the compressor to the evaporator) covered with frost on only one side - possible system clogged.
• 🔌 Wires and insulation: check whether the insulation of the wires going to the compressor is frayed. In refrigerators LG i Bosch there is often a problem with the cable rubbing against the body.

📌 Useful life hack: if the compressor is apparently intact, but does not start, try move the start relay (black box on the motor housing). Sometimes the contacts inside the relay “stick”, and a light tap returns them to working condition. If after this the refrigerator starts working, the relay requires replacement.

3. Sound check: what do clicks, buzzing and silence mean

Sound diagnostics are the fastest way to assess the condition of the compressor. Turn on the refrigerator and listen.

⚠️ Attention: In refrigerators with with an inverter compressor (for example, Samsung Digital Inverter, LG Smart Inverter) the operating sound is quieter and more uniform. If such a unit suddenly begins to hum loudly, this is a sign of a malfunction of the inverter board, and not the motor itself.

How to distinguish the sound of a working compressor from a faulty one?

A working compressor emits a low-frequency hum (like a running transformer), which can slightly change its tone when the load changes. A faulty motor often “whistles” at high frequencies, makes intermittent sounds, or operates intermittently. In models with two compressors (for example Atlant MXM-2835), one motor may hum, and the second may be silent, which indicates a failure of the second circuit.

4. Testing with a multimeter: step-by-step instructions for beginners

If visual inspection and sound diagnostics do not produce results, it’s time to take up the multimeter. We will check the integrity of the circuit. the resistance of the compressor windings. data-i="159">🔌 Screwdriver (to remove the relay cover). and circuit integrity.

What you will need:

• 🔧 Multimeter (the simplest model for 300–500 ₽ will do).
• 🔌 Screwdriver (for removing the relay cover).
• 📝 Paper and pen (to record the readings).

Procedure:

1. Disconnect the refrigerator from the mains and remove the start relay from the compressor (usually it is attached to latches or one screw).
2. On the compressor you will see 3 pins, marked with letters:
   • C (Common) - common pin;
   • S (Start) - starting winding;
   • R (Run) - working winding.

Switch the multimeter to resistance measurement mode (200 Ohm) and ring the windings:

• Between C and S (starting winding) - there should be resistance 20–40 Ohm.
• Between C and R (working winding) - 10–20 Ohm.
• Between S and R —the sum of the two previous values (30–60 Ohm).
• If at least one of the values is equal 0 Ohm (short circuit) or ∞ (break) - the compressor is faulty.

Disconnect the refrigerator from the network|Remove the starting relay|Find terminals C, S, R on the compressor|Ring the windings C-S, C-R, S-R|Compare the readings with the norm (20–60 Ohm)|Check the resistance between the compressor housing and the terminals (should be ∞)|Install the relay back-->

📌 Key conclusion: If the resistance between compressor housing and any of the terminals (C, S, R) is not equal to infinity - it is breakdown to the housing. Such a compressor is dangerous for operation (risk of electric shock) and must be replaced.

5. Checking the starting relay: why the compressor does not start

In 30% of cases. “compressor failure” is actually associated with faulty start relay. This small block is responsible for starting the motor and protecting it from overheating.

How to check the relay:

1. Remove the relay from the compressor (usually it is attached on latches or one screw).
2. Shake it - if you hear inside knock or rattling, this is a sign destruction of the core.
3. Ring with a multimeter, the relay contacts are in the mode 200 Ohm:
   • The resistance between the coil terminals should be 50–150 Ohm.
   • Between the power contacts (to which the wires from the compressor are connected) are in normal condition — ∞ (open).
• Connect the relay back and try to start the refrigerator. If the compressor buzzes, but does not start the relay does not work and requires replacement.

⚠️ Attention: B refrigerators Bosch and Siemens are often installed electronic relays (for example, Danfoss 103N0020they cannot be checked with a multimeter - only by replacing them with a known good one.

💡 Advice: If you don’t have a new relay at hand, you can temporarily connect the compressor directly by shorting the wires C and S for 1-2 seconds (to start). Do not hold it longer - this can burn windings!

6. Checking the voltage: is there power to the compressor

If the compressor does not show signs of life, it may simply not be receiving voltage. This may be due to:

- Faulty thermostat;

- Open circuit in the power supply;

- Damage to the control board (in modern models).

How to check:

1. Disconnect the refrigerator from the power supply.
2. Remove the cover covering the compressor terminals.
3. Locate the wires coming from the thermostat or control board to the compressor (usually they are connected to the terminals C and S via a relay).
4. Plug in the refrigerator and with a multimeter in AC 250V mode measure the voltage between these wires. Normally it should be 220–230 V.
5. If there is no voltage, check thermostat, fuse (in models Indesit it often blows) and power circuit.

⚠️ Attention: In refrigerators with electronic control (for example, Samsung RL-44, LG GA-B489) voltage is supplied to the compressor through the board. If it fails, the multimeter will show 0 V even with a working thermostat. In this case, diagnostics of the board is required.

7. Checking the pressure: how to find out if the compressor is pumping freon

If the compressor starts, but the refrigerator does not freeze, it may be does not create the required pressure in the system. This may be due to:

- Wear of the piston group;

- Freon leakage;

- Valve jamming.

How to check without a pressure gauge:

• 🔥 Heating. condenser: with the compressor running, touch the grille on the back wall of the refrigerator. Normally it should heat up (up to 50–60°C) - freon is not circulating.
• ❄️ Freezing of the tubes: thin tube (capillary) should be evenly cold. If it freezes only at the entrance to the evaporator, a blockage is possible.
• 🎯 Test with shutdown: turn off the refrigerator for 10 minutes, then turn it on. If the compressor starts, but after 1-2 minutes it turns off (and the condenser does not heat up) - it does not pump. freon.

📌 Important: If the compressor works but does not create pressure, you can try to “reanimate” it flushing the system (if the cause is a blockage) or refilling freon (if there is a leak). However, in 80% of cases the compressor needs to be replaced.

8. When the compressor is working, but the refrigerator is not working

If all tests have shown that the compressor is in order, but the refrigerator is not freezing, look for the reason in other components:

• 🌡️ Thermostat: in mechanical models (Biryusa, Atlant), the thermostat often fails. Check it by shorting the wires directly - if the compressor starts, the thermostat needs to be changed.
• 🔄 Control board: in refrigerators with a display (Samsung, LG), a board malfunction can block the compressor from starting. Symptom - errors flash on the screen (for example, E1, FF).
• ❄️ Freon leak: if the compressor is running, but the condenser does not heat up and the tubes are not frozen, there is no refrigerant in the system. Refilling is required.
• 🔌 Fuse: in some models (Indesit, Ariston) there is a thermal fuse on the compressor. If it is burned out, the motor will not start.

⚠️ Attention: In refrigerators with a system No Frost the reason for the lack of cold may be faulty fan or a frozen evaporator Check whether the blade is spinning in the freezer and whether there is ice on the back. wall.

FAQ: Frequently asked questions about checking the compressor

Is it possible to check the compressor without removing it from the refrigerator?

Yes, most checks (sound diagnostics, measuring winding resistance, checking voltage) can be performed without dismantling. The compressor must be removed only for replacement or deep diagnostics (for example, checking the pressure with a pressure gauge).

The compressor hums, but does not start - what to do?

This is a typical sign of a malfunction. starting relay or turn-to-turn short circuit in the windings. Try replacing the relay (costs 500–1500 RUR). If that doesn’t help, test the windings with a multimeter. Resistance below 20 Ohms or equal to 0 indicates a short circuit.

What multimeter is needed to check?

Any digital multimeter with a mode for measuring resistance (ohmmeter) and voltage (voltmeter) will do. For example, DT-830B, Mastech MS8229 or even budget models for 300–500 rubles. the error was no more than 2–3%.

How much does it cost to replace a compressor?

The cost depends on the model of the refrigerator and the type of compressor:

• Linear compressor (for example, for Atlant, Biryusa) — 4 000–8 000 ₽;
• Inverter compressor (Samsung, LG) — 8 000–15 000 ₽;
• Foreman's work (replacement + freon refill) - 3,000–6,000 ₽.

For refrigerators older than 10 years, compressor replacement is frequent unprofitable - it’s cheaper to buy a new one.

Is it possible to repair the compressor or just replace it?

The compressor is a sealed unit, and not repair in the classical sense. In rare cases, the master can:

• Change the oil and clean the system (if the cause is clogged);
• Rewind the windings (expensive and unreliable);
• Replace the valve (requires special equipment).

In 95% of cases it is easier and cheaper to install a new one compressor.