The refrigerator hums, but does not start: 7 reasons and solutions

The situation is familiar to many: the refrigerator suddenly begins to hum loudly, but the compressor does not start, and the chambers become warmer every minute. The first thought is to urgently call a technician, but often the problem can be solved on your own, saving time and money. Humming without starting is one of the most common symptoms of malfunctions, and its causes range from a simple network failure to serious breakdowns of the compressor or electronics.

In this article we let's look at why the refrigerator hums but does not freeze - from simple ones (for example, a door that is not tightly closed) to complex ones (an interturn short circuit in the motor winding). You will learn how to carry out all possible reasonsreasons why the refrigerator hums but does not freeze - from simple ones (for example, a door that is not tightly closed) to complex ones (an interturn short circuit in the motor winding). You will learn how to conduct primary diagnostics without tools, what manipulations you can do with your own hands, and in what cases It’s not worth the risk. We will also give a checklist to check before calling a technician and tell you how to avoid repeated breakdowns.

⚠️ Important: If the refrigerator Indesit, Samsung, Atlant or another brand with The system No Frost hums and does not start, do not try to defrost it with a hairdryer or hot water - this may damage the evaporator. Use only natural thawing at room temperature.

1. Why the refrigerator hums but does not turn on: top 7 reasons

A hum without starting the compressor is a signal that electricity is supplied to the motor, but something is preventing its normal operation. Let's look at the main reasons, starting with the simplest ones:

• 🔌 Power supply problems: voltage surges, faulty socket or surge protector. The refrigerator may “hum” due to Attempts of the starter to start the compressor at low voltage.
• 🚪 Not tightly closed door: If the seal is worn out or a foreign object is interfering (for example, a bag of food), the thermostat does not give the command to start.
• ❄️ Frozen fan (in No Frost models): ice blocks the blades, the fan motor hums, but does not rotate.
• 🔧 Fault start-protective relay: the relay "clicks" but does not close the circuit to start the compressor.
• 🔥 Interturn short circuit in the compressor: the motor tries to start, but the overheating protection is triggered.
• 📉 Failure of the thermostat or electronic unit: the control board does not send a signal to start.
• ⚡ Condenser breakdown: the compressor does not receive a sufficient “push” to start.

Most of these reasons can be diagnosed independently, but to repair some components (for example, compressor or electronic board) you will need special tools and knowledge.

2. First steps: what to do if the refrigerator is humming but not freezing

Before disassembling the refrigerator or calling the service center, follow these steps:

1. Check the power supply. Unplug the refrigerator from the outlet for 1-2 minutes, then turn it on again. Sometimes this helps reset frozen electronics.
2. Inspect the door. Make sure it is closed tightly and the seal is not damaged. Check if food or shelves are in the way.
3. Listen to the sounds. If the hum does not come from the compressor (usually from the bottom at the back), but from the top, the problem may be in the fan (No Frost).
4. Check the temperature in the chambers. If the refrigerator does not cool at all, but the freezer works - the thermostat is to blame or there is a blockage in the capillary tube.

If after these manipulations the refrigerator does not work, proceed to in-depth diagnostics.

3. Diagnostics of the compressor: how to understand whether the motor is alive

The compressor is the “heart” of the refrigerator, and its malfunction is often manifested by a buzzing sound without starting. Here’s how to check its condition:

• 🔊 Sound. If the compressor hums, but does not start, and after 5-10 seconds a click is heard (the protection is activated) - there may be a problem with the windings or relays.
• 🌡️ Temperature. Touch the compressor with your hand: if it is hot, this may indicate an interturn short circuit or overload.
• 🔧 Check with a tester. Turn off the refrigerator, remove the cover from the compressor terminals and measure the resistance between the terminals:
  • Common point (C) - Start winding (S): ~20–40 Ohm
  • Common point (C) - Working winding (R): ~10–20 Ohm
  • S — R: the sum of the two previous values (~30–60 Ohm)

  If the resistance is 0 or ∞ - open or short circuit.

A critical sign of a compressor malfunction: if, when trying to start, the machine in the control panel is triggered or the RCD is knocked out, the motor must be replaced.

4. Start-up protection relay: how to check and replace

The relay is a compressor “switch” that supplies current to the starting unit. winding and protects the motor from overheating. If it is faulty, the compressor will hum, but will not start. Here is how to diagnose it:

1. Remove the relay. It is attached to the compressor and has 2-3 wires (depending on the model). data-i="137">Between the terminals
2. Ring with a multimeter. Between pins 3 and 4 (if there is a numbering) the resistance should be ~10–20 Ohms. Between 1 and 2 there is a break (∞).
3. Check mechanically. Shake the relay - if something rattles inside, this is a sign of a breakdown.

If the relay is faulty, replace it with a similar one. Atlant, Biryusa or Sarov universal relays RP4-1 or DANFOSS 103N0010are suitable. For LG and Samsung it is better to take original spare parts.

5. Problems with No Frost: why the fan is humming and the refrigerator does not work

In refrigerators with the system No Frost the hum may not come from the compressor, but from the fan that blows on the evaporator. If it is frozen or broken, the refrigerator will stop cooling, but the compressor may not turn on due to protection.

How to check:

1. Unplug the refrigerator.
2. Remove all food from the freezer.
3. If ice blocks the fan blades - defrost the refrigerator at least 12 hours.
4. After defrosting, check whether the fan rotates manually. If not, replacement is required.

⚠️ Attention: Do not try to speed up defrosting with a hairdryer or hot water - this may damage the plastic parts and the evaporator. Use only natural defrosting at room temperature.

What if the fan does not spin even after defrosting?

If the fan does not rotate freely or makes a squeaking sound, it must be replaced. For models Indesit and Ariston a fan is suitable EBM W2E200-SW22-01, for Samsung — DC Fan 12V. Before replacing, turn off the refrigerator and discharge the capacitor (if there is one in the fan circuit).

6. Thermostat and electronic board: hidden culprits of failure

If the compressor and relay are working, but the refrigerator does not start, the problem may lie in thermostat (in mechanical models) or control board (in electronic ones).

How to check the thermostat:

1. Find the thermostat - it is usually located inside the refrigerator compartment, behind the plastic panel.
2. Remove the terminals and short them together (jumper). If the compressor starts, the thermostat is faulty.
3. Test the thermostat with a multimeter: in the "maximum" position the resistance should be ~0 Ohm, in the "off" position - ∞.

Symptoms of a faulty board:

• 🔄 The refrigerator turns on and immediately turns off (cyclically).
• 📛 Errors flash on the display (for example, E1, F2 —see the instructions for the model).
• 🔌 The indicators are on, but the compressor does not respond.

Repairing the board requires special skills (resoldering capacitors, microcontroller firmware). If you are not sure, it is better to contact the service.

7. When to call a technician: 5 signs of a serious breakdown

Some faults cannot be repaired without professional equipment. Contact a technician if:

• ⚡ The compressor is humming, but the machine in the panel is triggered (interturn short circuit).
• 🔥 Compressor housing heated to a temperature that burns your hand.
• 🛠️ On the relay or board you can see blackened radio elements or swollen capacitors.
• ❄️ After defrosting No Frost fan does not start, and ice quickly builds up on the evaporator.
• 📉 Refrigerator turns on for 1-2 seconds and turns off (the cycle repeats endlessly).

The cost of repair depends on the breakdown:

• Replacement of the start-up relay: 1 500–3 000 ₽.
• Repair of the control board: 3 000–6 000 ₽.
• Replacement of the compressor: 8 000–15 000 ₽ (including refueling freon).

⚠️ Attention: If the refrigerator is more than 10 years old, replacing the compressor may not be cost-effective. Compare the cost of repairs with the price of a new refrigerator (for example, ATLANT MHM 2835-100 costs ~30,000 ₽).

FAQ: Frequently asked questions about hum refrigerator without starting

The refrigerator hums, but does not start after the lights are turned off. What to do?

Most likely, the compressor protection has tripped due to a power surge. Unplug the refrigerator for 10-15 minutes, then turn it on again. If the problem persists, check voltage stabilizer or surge filter. In rural areas, it is recommended to use voltage control relay (for example, Zubr R116y).

Is it possible to replace the compressor yourself?

Theoretically, yes, but this is a complex procedure that requires:

• Special equipment for vacuuming the system.
• Refilling freon (the type of refrigerant depends on the model).
• Soldering copper tubes.

Without experience, you risk releasing freon or damaging the capillary tube.

Why does a new refrigerator hum, but not? freezing?

Possible reasons:

• 📦 Transport bolts not removed (they secure the compressor during transportation).
• ⚙️ Incorrectly installed cooling mode (for example, "Holiday" is on).
• 🔌 Malfunction from the factory (warranty case).

Check whether the bolts are removed (they are located on the back wall of the compressor) and set the mode Super Freeze for 2-3 hours.

How long can food be stored if the refrigerator is not working?

The timing depends on the type of food and the temperature in the room:

Product	Temperature in the room	Maximum shelf life
Meat, fish (raw)	+20°C	2–4 hours
Dairy products	+18°C	6–8 hours
Vegetables, fruit	+25°C	12–24 hours

If the refrigerator does not start for more than a day, it is better to throw away the food or prepare it urgently.

How to avoid breakdowns in the future?

Preventive measures:

• 🔌 Use voltage stabilizer (especially in rural areas).
• 🧊 Defrost the refrigerator every 6-12 months (even No Frost).
• 🚪 Keep an eye on door seal —clean it from dirt and grease.
• 🌡️ Do not place the refrigerator next to battery or stove.