The refrigerator turns on and immediately turns off: 10 reasons and what to do

Have you noticed that the refrigerator has started to work unstable: the motor starts for a few seconds, hums loudly, and suddenly turns off? This behavior is not only annoying, but also signals serious problems. Cyclic on-off (short cycles) can lead to food spoilage, compressor overheating and even fire in rare cases. In 80% of cases, the reason lies in 5 key components: thermostat, start-up relay, compressor, electrical circuit or freon leak.

In this article we We will analyze exact symptoms for each type of fault, diagnostic methods without calling a technician (including tests with a multimeter), and also give step-by-step instructions for do-it-yourself repairs. Let us pay special attention models with No Frost to their defrosting system often becoming the culprit of such failures. If your refrigerator Indesit, Samsung, Atlant or LG behaves suspiciously - here you will find answers taking into account the characteristics of these brands.

⚠️ Warning: If the refrigerator turns off with pop or sparking in the compressor area —immediately de-energize it and do not turn it on until the electrical circuit is checked. This is a sign of a short circuit in the motor windings or a breakdown of the starting capacitor.

1. Thermostat: why the refrigerator “thinks” it’s already cold

The thermostat (or thermostat) is the “brain” of the refrigerator that controls the temperature. When it breaks, the compressor receives false signals and operates erratically. Classic symptoms of a thermostat malfunction:

• 🔄 The refrigerator turns on for 5-10 seconds and turns off, repeating the cycle every 2-3 minutes.
• ❄️ There is ice in the freezer, and the main compartment is too warm (or vice versa).
• 🔊 Clicking sounds when when turned on/off, the thermostat relay is triggered.

How to check the thermostat yourself? Disconnect the refrigerator from the mains, remove the protective casing from the temperature regulator (usually located inside the chamber or on the top panel) and:

1. Find the two wires going to the thermostat and connect them together (use a screwdriver with an insulated handle!).
2. Plug in the refrigerator. If the compressor starts working and does not turn off, the thermostat is faulty.

⚠️ Attention: Do not leave the wires closed for more than 1-2 minutes! A compressor without thermostat control may overheat.

Cost of a new thermostat for popular models:

2. Start-up relay: why the compressor “stutters”

The start-up relay is responsible for starting the compressor and protecting it from overloads. If the relay is burnt out or jammed, the refrigerator will:

• 🔊 Buzz loudly when trying to start, but the motor does not spin.
• ⚡ Turn off after 1-3 seconds with a characteristic click.
• 🔥 Heat up in the area of the relay (you can feel hand).

Relay diagnostics:

1. Turn off the refrigerator, remove the relay cover (usually a black plastic box next to the compressor).
2. Check the contacts for melting or blackening - this is a sign of a short circuit.
3. Test the relay coil with a multimeter (resistance should be 20–50 Ohms). If the device shows “1” (break), the relay needs to be replaced.

💡 Tip: In models Samsung and LG of the last years they often install electronic relays (for example, RLS-3 or DANFOSS 103N0240). They cannot be checked with a multimeter - only by replacing them with a known working one.

3. Compressor: when the motor is “tired” or jammed

If the compressor is worn out or jammed, it will try to start, but will immediately turn off due to protection. Signs of problems with the motor:

• 🔇 The refrigerator hums, but does not freeze (the compressor does not create pressure).
• 💥 When turned on, you can hear metal knock the pistons hitting the valves.
• 🔥 The compressor housing gets very hot (more than 70°C).

How to check the compressor:

1. Turn off the refrigerator, wait for the motor to cool down (1-2 hours).
2. Remove the start relay and ring compressor windings:
   • Resistance between C (common) and S (starting) — 20–30 Ohms.
   • Resistance between C and R (working) — 10–15 Ohm.
   • Resistance between S and R —the sum of the two previous ones (30–45 Ohms).

If at least one value is “0” (short circuit) or “1” (break), the compressor is faulty.

⚠️ Attention: In refrigerators No Frost (for example, Samsung RL-34 or LG GA-B489) the compressor may turn off due to frozen fan. Before diagnosing the motor, check whether the blade is spinning in the freezer!

How to distinguish a faulty compressor from problems with the relay?

If when connecting the compressor directly to the network (bypassing relay) it does not start or heats up quickly - the motor is at fault. If it works stably, the problem is in the relay or thermostat.

4. Freon leak: when the refrigerator “loses cold”

Freon is a refrigerant that circulates through the system and removes heat. When it leaks, the compressor runs idle: it turns on, but cannot create the required pressure, so it quickly turns off. Signs of a leak:

• ❄️ The refrigerator hardly cools, but the motor hums constantly.
• 🧊 The condenser (grid at the back) remains cold (normally it should heat up).
• 🛠️ Visible marks on the tubes or at soldering points oil stains (freon leaves along with the oil).

It is difficult to eliminate the leak on your own - it requires evacuating the system refilling freon. But you can check for leaks using a soap solution:

1. Apply the solution to suspicious areas (soldering, pipe bends).
2. If bubbles appear, there is a leak.

💡 Useful advice: In models with No Frost leaks often occur freezer evaporator due to corrosion. If your refrigerator is older than 7 years, the probability of this defect is higher than 60%.

5. Electrical problems: why the refrigerator "jerks"

Unstable voltage or damaged wiring can cause short on-off cycles. Check:

• 🔌 Voltage in the outlet (should be 220–230 V). Use a tester or connect another device.
• 🔌 Condition of the plug and power cord (are there any melting or cracks).
• 🔌 Operation surge protector (if the refrigerator is connected through it).

🔧 How eliminate:

• Connect the refrigerator directly to the outlet (without extension cords).
• Install voltage stabilizer (especially important for rural areas).
• Replace the power cord if visible damage.

⚠️ Attention: If when you turn on the refrigerator the machine in the panel is knocked out this is a sign of a short circuit in the compressor or defrosting heating element. Immediately turn off the device and call an electrician!

6. No Frost system: why the refrigerator “chokes”

In models with No Frost (for example, Samsung RB-30, LG GA-B459) short cycles are often associated with a malfunction of the defrost system. Signs:

• ❄️ Ice is building up in the freezer (even if it should be dry).
• 🔇 The fan does not spin or is noisier than usual.
• 🔥 The defrost heating element does not heat up (check with your hand - it should be warm).

How to diagnose:

1. Turn off the refrigerator, defrost it completely (24 hours).
2. Check defrost fuse (located next to the heating element) - ring with a multimeter (resistance should be 0 Ohm).
3. If the fuse is blown, replace it and the heating element (they often fail in pairs).

📌 Key conclusion: If after defrosting the refrigerator works normally for 1-2 days, and then starts to turn off again, the problem is definitely in the system. No Frost. The heating element or defrost sensor needs to be replaced.

7. Sensors and electronics: when the “brains” of the refrigerator fail

Modern refrigerators are equipped with many sensors (temperature, humidity, door position). If at least one of them transmits incorrect data, the control unit may command the compressor to switch off prematurely. Common problems:

• 🚪 The door sensor does not work - the refrigerator “thinks” that the door is open and turns off the motor.
• 🌡️ Evaporator sensor is covered with ice and shows the wrong temperature.
• 🔧 Control board failed (often after a power surge).

How to check the sensors:

1. Turn off the refrigerator, find the sensors (usually small plastic boxes with wires).
2. Ring them multimeter:
   • Door sensor: resistance 0 Ohm when the door is closed, "1" (open) - when open.
   • Temperature sensor: resistance changes when heated (for example, from 5 kOhm to 1 kOhm).

⚠️ Attention: In refrigerators Bosch i Siemens the control board often suffers from condensation. If traces of corrosion are visible on it, replacement is required (cost 3,000–8,000 rubles).

8. When to call a specialist: 3 cases when amateur activity is dangerous

Some malfunctions require professional intervention. Contact the service center if:

1. 🔧Required refilling freon or soldering of pipes (special equipment is required).
2. ⚡ There are signs breakdown to the case (electric shock when touched).
3. 💻 Faulty control board (needs programming after replacement).

💰 Repair cost in 2026 (Moscow and region):

📌 Advice for choosing a technician: Before repair, ask for diagnostics with disassembly (costs 500–1,000 ₽). An honest technician will show you the faulty part and explain why it needs to be replaced.

FAQ: Frequently asked questions about the unstable operation of the refrigerator

❓ The refrigerator turns on and immediately turns off - could this be because of the heat?

Yes, If the room temperature is above 30°C, the compressor may overheat and shut down. Solution: provide ventilation (move the refrigerator 10 cm away from the wall) or install an air conditioner.

❓ Why does a new refrigerator work jerkily in the first days?

This is normal! In the first 2–3 days after switching on, the refrigerator “grinds in”: freon is distributed throughout the system, and the compressor is adjusted to the load. If the cycle has not stabilized after a week, look for a malfunction.

❓ Is it possible to replace the compressor yourself?

Technically yes, but it is risky. Required:

• Special tool for soldering tubes.
• Vacuum pump for pumping out air.
• Accurate dosage of freon (excess or deficiency will lead to breakdown).

Errors during replacement compressor often leads to repeated breakdown within a month.

❓ The refrigerator turns off with error E1 (or another code) - what to do?

Error codes depend on the model. Explanation for popular brands:

Brand	Code	Value
Samsung	E1	Problem with the freezer temperature sensor
LG	ER DH	The door is not closed or the sensor is broken
Indesit	F04	Compressor malfunction
Atlant	H1	Motor overheating

Look for the exact explanation in the instructions for your model.

❓ How much does it cost to diagnose a refrigerator at home?

In 2026, the average cost:

• Moscow and St. Petersburg: 1,000–1,500 ₽ (free if you order repairs).
• Regions: 500–1,000 ₽.

⚠️ Beware of “free diagnostics” - Often this is hidden under the imposition of unnecessary repairs.