How to check the refrigerator engine yourself: instructions with photos and tips

The engine (compressor) is the “heart” of the refrigerator, on which its performance depends. If the unit stops freezing, makes strange sounds or does not turn on at all, the first thing you need to check is this particular unit. In 70% of cases, refrigerator malfunctions are associated with a breakdown of the compressor or its auxiliary elements - the starting relay, windings, capacitor.

You can check the refrigerator engine yourself, without resorting to the services of a technician. To do this, you will need basic knowledge of electrical engineering, a multimeter (or tester) and a screwdriver. In the article we will analyze step-by-step diagnostics with photos, typical signs of a malfunctionand also give advice on how to distinguish a compressor breakdown from problems with a thermostat or electronic board.

Signs of a refrigerator motor malfunction

Before disassembling the refrigerator, pay attention to its “behavior.” Some symptoms clearly indicate problems with the compressor:

• 🔊 Loud hum or knocking during operation - may indicate mechanical wear of the pistons or bearings.
• ❄️ Doesn’t freeze, but the light inside is on - the compressor does not create the necessary pressure for freon circulation.
• ⚡ Clicks without starting —the starting relay is triggered, but the engine does not start (a winding break or jamming is possible).
• 🔥 Overheating of the compressor housing —if it is too hot (more than 70°C), this may be a sign of interturn short circuit.
• 🕒 Frequent on/off —the compressor operates jerkily, not having time to gain the required power.

If the refrigerator Indesit, Atlant or Samsung Over 10 years, the likelihood of engine wear is higher. Modern models (for example LG Inverter Linear Compressor) have a compressor lifespan of up to 20 years, but they are not insured against breakdowns due to power surges or factory defects.

Important! Some symptoms (for example, lack of cold) may be caused not by a compressor breakdown, but by a freon leak, a malfunction of the thermostat, or blockages in the capillary tube. Therefore, diagnostics must be carried out comprehensively.

Preparation for testing: tools and safety measures

To diagnose the refrigerator engine you will need:

• 🔧 Screwdriver cross/flat — to remove the protective casing.
• 📊 Multimeter (or tester) - for checking windings, relays and capacitors.
• 🔌 Extension cord with grounding - for safe connection.
• 🧲 Magnet (optional) - to check whether the rotor rotates.
• 📸 Smartphone - to fix the location of the wires before turning off.

Before starting work be sure to unplug the refrigerator and defrost it (if it does not work, 1-2 hours are enough for alignment temperature). Do not touch the compressor immediately after turning it off - it can be hot (up to 90°C).

⚠️ Attention: If the refrigerator is connected to the network through a voltage stabilizer, check its serviceability. Voltage surges are one of the main reasons why compressors fail. walls. Beko And Bosch.

The location of the compressor depends on the model:

• Most refrigerators (Atlant, Stinol, Samsung) it is located at the bottom of the back wall.
• In some models LG i Liebert the compressor can be hidden under the decorative panel.
• In Side-by-Side (for example, Samsung RS62R5001M9) the engine is usually located on the side.

Step 1: External inspection of the compressor

Remove the back cover of the refrigerator (it is secured with 4-6 screws). Inspect the compressor - it is a black or gray metal cylinder with pipes and a terminal block. Pay attention to:

• 🔍 External damage —cracks, dents, traces of oil (leakage).
• 🔗 Condition of the tubes —they must be intact, without oxidation or kinks.
• 🔌 Terminals and wires —there should be no melting or burnt contacts.
• 💧 Condensation or rust —this may indicate moisture ingress.

If the compressor is covered with a thick layer of dust, clean it with a soft brush. Do not use a damp cloth —this may cause a short circuit the next time you turn it on.

Pay attention to starting relay —a small box attached to the compressor. If it is cracked or melted, it needs to be replaced. In models Indesit i Ariston the relay often fails due to overheating.

Step 2: Checking the compressor windings with a multimeter

The most reliable way diagnostics - measurement of winding resistance. To do this:

1. Disconnect the terminal block from the compressor (usually it is secured with a latch or screw).
2. Set the multimeter to measure resistance (Ω) in the 200 Ohm range.
3. Connect the probes to the compressor contacts (usually their three: C — common, S — starting winding, R —working).

Normal resistance values for most household refrigerators:

If the device shows:

• 🔄 0 Ohm —short circuit in the winding.
• ∞ Infinity —winding break.
• 📉 The values are very different from the norm — interturn short circuit.

In any of these cases, the compressor is faulty and requires replacement. The exception is models with inverter motors (LG Linear Compressor, Samsung Digital Inverter), where the resistance may differ. For them, it is better to check the technical documentation.

Step 3: Diagnostics of the starting relay and capacitor

If the compressor does not start, but the windings are OK, the problem may be starting relay or capacitor. To check them:

1. Remove the relay from the compressor (it is attached with latches or screws).
2. Ring the relay contacts with a multimeter in resistance mode:
   • Between normally closed contacts (usually 1–2), the resistance should be ~0 Ohm.
   • Between normally open (1–3) is infinity.

Check the capacitor (if it is external):

• Switch the multimeter to capacitance measurement mode (F).
• The nominal value must match marking (usually 10–40 µF).

In relay models Atlant i Birusa contacts often burn out due to overloads. If a knocking sound is heard when shaking the relay, this is a sign of mechanical wear (replacement is needed).

⚠️ Attention: Capacitors can retain a charge even after being disconnected from the network. Before checking discharge it, shorting the terminals with a screwdriver with an insulated handle.

If the relay is working properly, but the compressor does not start, try connecting it directly (without a relay), applying voltage to windings C and S for 1-2 seconds. Do not hold longer - this can burn the winding!

How to test a relay without a multimeter?

If you don’t have a tester at hand, you can temporarily install a known-good relay from another refrigerator (suitable in power). If the compressor starts working, the problem is in the relay.

Step 4: Checking the performance of the compressor under load

If the windings, relay and capacitor are working, but the refrigerator does not freeze, you need to check compressor performance. To do this:

1. Connect the compressor to the network (via a relay).
2. Measure the current consumption using current clamps or a multimeter in ammeter mode (connect in series!).
3. Compare with the rated current indicated on the compressor nameplate (usually 0.8–1.5 A).

Symptoms of malfunction:

• 📈 Current is higher than normal — interturn short circuit or mechanical jamming.
• 📉 Current is below normal —wear of the piston group, freon leakage.
• 🔄 Current jumps —unstable operation of the valves.

In inverter compressors (Panasonic, Hitachi), the current can vary smoothly depending on the load. If it is stable, but there is no cold, the problem may be refrigerant leak or a clogged capillary tube.

Also listen to the sound of the compressor running:

• ✅ Smooth hum — normal.
• ❌ Knocking or grinding - wear of bearings or pistons.
• ❌ Clicks with pauses - malfunction of the relay or windings.

Step 5: Diagnostics without a multimeter (alternative methods)

If you don’t have a tester at hand, you can check the compressor in other ways:

• 🧲 Checking the rotor with a magnet:
  1. Disconnect the compressor from network.
  2. Apply the magnet to the compressor housing.
  3. If the rotor rotates (a slight knocking sound is heard), the mechanical part is working properly.
• 🔌 Direct connection to the network (only for experienced ones!):
  1. Disconnect the starting relay.
  2. Apply 220V voltage to the contacts for 1-2 seconds C i S.
  3. If the compressor starts, the problem is in the relay or capacitor.
• 👂 Check for tightness:
  1. Disconnect the compressor tubes.
  2. Blow into the inlet (where the tube from the evaporator was).
  3. If air flows freely, the valves are faulty.

⚠️ Attention: Direct connection of the compressor to the network is dangerous! Risk of electric shock or damage to windings. Use this method only if you are confident in your skills.

For models with inverter compressors (LG, Samsung), these methods may not be suitable - their electronics are sensitive to direct connection. In this case, it is better to contact a specialist.

When to call a specialist, and when you can repair it yourself

Independent compressor repair is justified in the following cases:

• ✅ Replacement starting relay or capacitor is a simple procedure that does not require special skills.
• ✅ Cleaning the compressor from dust or replacing thermal protection relay.
• ✅ Diagnostics of windings with a multimeter (if you know how to use it).

A call to a technician is necessary if:

• ❌ Required replacement of the compressor —special tools are needed for refilling freon and soldering pipes.
• ❌ Yes refrigerant leak —you can’t do without equipment for vacuuming the system.
• ❌ Faulty electronic control board (in models Samsung No Frost, LG Smart Inverter).
• ❌ Compressor jammed —attempts to “unwedge” it often lead to final failure.

The cost of replacing a compressor at a service center is 50–70% of the price of a new refrigerator. If your equipment is older than 10 years (for example, ZIL-63 or Minsk-15M), it is more economical to buy a new unit.

FAQ: Frequently asked questions about checking the refrigerator motor

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

Yes, external inspection and checking the windings with a multimeter can be carried out without dismantling. However, to replace the relay or capacitor, the compressor will have to be disconnected from the tubes (soldering will be required).

How to distinguish a compressor malfunction from a freon leak?

If the compressor is running but not freezing, touch the condenser (the grill on the back wall). If it is cold, there is little or no freon. If it is hot, the problem is in the compressor or the capillary tube is clogged.

Why does the compressor hum but does not start?

This is a typical sign. malfunction starting relay or capacitor. Less commonly, a break in the starting winding. Check the relay for melting and ring the capacitor.

does it cost to replace a compressor in a refrigerator?

The cost depends on the model:

• For budget refrigerators (Atlant, Indesit) - 8,000–15,000 rubles.
• For premium ones (Liebherr, Samsung) - 15,000–25,000 rubles.
• For Side-by-Side - from 20,000 rubles.

The price includes work + freon refilling.

Is it possible to turn on a refrigerator with a faulty compressor?

No, this is dangerous! If the windings are shorted, a fire may occur. If the compressor is jammed, the starting relay will burn out. If you suspect a malfunction, it is better to disconnect the refrigerator from the network.