The refrigerator suddenly stopped freezing, and the compressor turns on for a couple of seconds, then turns off again? Or does the motor run non-stop, but the chambers are warm? Most likely the problem lies in start relay a small but critical unit that controls the start of the compressor. This part breaks down more often than it seems: according to statistics from service centers, up to 30% of calls about a “non-working refrigerator” are related to it.
In this article we will look at how diagnose a relay malfunction yourself without disassembling the equipment - based on indirect signs, sounds and behavior of the refrigerator. You will learn which symptoms accurately indicate a relay failure, and when the compressor or thermostat is to blame. We will also give a checklist for an express check and explain why some “folk” diagnostic methods can harm equipment.
Important: if you have never repaired refrigerators, do not rush to disassemble the relay or compressor. In 80% of cases, external observations and simple tests are enough to confirm the diagnosis - we will describe them below.
What is a relay in a refrigerator and why does it break
A relay (or start-up protection relay) is an electromechanical device that performs two key functions:
- 🔌 Start the compressor —supplies current to the motor winding at the moment of switching on.
- 🛡️ Overheat protection —turns off the power if the compressor runs for too long or overheats.
Modern refrigerators (Indesit, Samsung, Atlant, Liebherr) use two types of relays:
- Electromechanical — with a spring mechanism and a bimetallic plate (an outdated type, but still found in budget models).
- Electronic (posistor) —without moving parts, with a thermistor instead of a bimetal (more reliable, but sensitive to voltage surges).
The main reasons for relay failure:
- ⚡ Power surges —even a one-time surge up to 250V can burn the contacts.
- 🕰️ Natural wear —the spring loses its elasticity, the contacts oxidize (service life: 5–10 years).
- 🔥 Overheating compressor —if the refrigerator is in a hot room or the ventilation is blocked.
- 💧 Corrosion —at high humidity (relevant for models without anti-corrosion coating).
7 main signs of a faulty relay
Problems with the relay manifest themselves in a very specific way. Here key symptomsthat should alert you:
| Symptom | What is happening | Probable cause |
|---|---|---|
| The compressor “clicks” and turns off | The motor tries to start, but after 1-3 seconds the protection is triggered. The cycle is repeated every 5–10 minutes. | The starting winding does not work (break or sticking of the relay contacts). |
| The refrigerator does not cool, but the light inside is on | The compressor does not start at all, although power is supplied to it. | Open circuit in the relay or malfunction of the starting capacitor. |
| The motor runs without stopping | The compressor hums constantly, but the temperature in the chambers does not drop to normal. | Sticking of the relay contacts in the “on” position (often accompanied by a burning smell). |
| Extreme heating of the relay | The relay body is hot (more than 60°C), smoke or a smell of burning plastic may appear. | Short circuit or current overload. |
| The refrigerator turns on every other time | Sometimes the compressor starts normally, sometimes only after 2-3 attempts. | Wear of the spring mechanism (in electromechanical relays) or unstable contact. |
Critical symptom: if the compressor turns on for 1-2 seconds and immediately turns off with a loud click - in 95% of cases the relay or starting capacitor is to blame. This is the only sign that almost unambiguously indicates this breakdown.
How to distinguish a relay failure from problems with the compressor or thermostat
The same symptoms (lack of cold, clicking sounds, constant operation of the motor) may indicate malfunction of other components. Here's how to differentiate problems:
1. Relay vs. compressor
- 🔧 The relay is faulty:
- The compressor tries to start (a hum is heard), but turns off after 1-3 seconds.
- When started manually (if the relay contacts are briefly closed), the motor works normally.
- 🔧 Broken compressor:
- The motor shows no signs of life (no hum, no clicks).
- When checked with a multimeter, the windings show an open or short circuit.
2. Relay vs. thermostat
- 🌡️ Problem in the relay:
- The compressor does not respond to turning the thermostat knob.
- Forced starting of the motor (by closing the contacts) works.
- 🌡️ Thermostat is broken:
- The compressor does not turn on at all, but when the thermostat contacts are closed, it starts.
- In refrigerators with electronic control, an error may appear on the display (for example,
E1orF2).
How to check the thermostat without a multimeter?
Remove the plastic thermostat knob and find the two contacts under it. Carefully close them with a screwdriver (after disconnecting the refrigerator from the network!) If the compressor starts, the thermostat is faulty. If not, the problem is in the relay or compressor.>
⚠️ Attention: Do not try to start the compressor bypassing it. relay for a long time (more than 10 seconds)! This can lead to overheating of the windings and final breakdown of the motor.
Step-by-step diagnostics of the relay without disassembling the refrigerator
Before removing the relay, perform these tests. They will help confirm or refute the diagnosis:
- Checking. sounds:
- Listen to the compressor. Normal cycle: click (relay on) → engine hum → silence (shutdown).
- If the relay is faulty: click → hum for 1-2 seconds → click (shutdown).
- Temperature test:
- Feel the relay housing (usually located next to the compressor at the bottom of the refrigerator). If it is scalding hot it is a sign of stuck contacts.
- Set the AC voltage measurement mode (~220V).
- Connect the probes to the relay contacts (be sure to turn off the refrigerator before doing this!) Normal: resistance between the contacts
30–100 Ohm.
Listen to the compressor for cyclic clicks|Check the temperature of the relay body|Inspect the relay for melting or cracks|Try to start the refrigerator after a 30-minute disconnection from the network
If all signs point to the relay, proceed to the next section. If the symptoms are ambiguous - contact a specialist. Replacing the relay yourself will cost 500–1500 rubles (depending on the model), while diagnostics in the service will cost from 2000 rubles.
How to temporarily start a refrigerator with a faulty relay (emergency method)
If the relay breaks down in the heat of the day or at night, and food cannot be left without cold, you can short-term start the compressor bypassing the faulty unit. This method is only suitable for electromechanical relays!
You will need a screwdriver with an insulated handle and rubber gloves. Proceed as follows:
- Disconnect the refrigerator from the network.
- Remove the relay cover (usually it is secured with latches or one screw).
- Find the two contacts going to the compressor (usually they are marked
CiS). - Carefully close them with a screwdriver for 1-2 seconds. If the compressor starts, the problem is definitely in the relay.
- 💰 Budget models (Atlant, Biryusa): 400–800 rubles.
- 💰 Middle segment (Indesit, Samsung): 800–1500 rubles.
- 💰 Premium (Liebherr, Bosch): 1500–3000 rubles.
- 🆔 Marking (must match the original).
- 🔌 Mounting type (clips or screws).
- 📏 Dimensions (some relays are visually similar, but not interchangeable).
⚠️ Attention: Do not keep the contacts closed for more than 3 seconds! This may burn the compressor starting winding. Also do not use this method. more than 1 time per hour.
This method will help you last 12-24 hours before replacing the relay. However, remember: working without protection is dangerous the compressor may overheat.
When a relay needs to be repaired, and when only replaced
In most cases, the relay is not repaired, but replaced. However, there are exceptions:
| Type of failure | Can it be repaired? | Cost of repair/replacement |
|---|---|---|
| Oxidation of contacts | Yes (cleaning with alcohol or sandpaper) | Free (on your own) |
| Spring breakage (in mechanical relays) | Sometimes (spring replacement) | 300–800 rubles |
| Contact burnout | No (replacement required) | 500–1500 rubles |
| Crack in the case | No (risk of electric shock) | Replacement required |
If the relay is electronic (posistor), repair is impossible - only replacement. In mechanical relays it is sometimes possible to restore functionality, but this is a temporary solution.
The cost of a new relay depends on the model of the refrigerator:
When purchasing a relay, be sure to check:
⚠️ Attention: Parts for refrigerators with inverter compressors (Samsung Digital Inverter, LG Linear Compressor) are incompatible with conventional relays. Check compatibility with the seller!
What will happen if you do not change the faulty relay
Ignoring the problem will lead to cascade breakdowns:
- Compressor overheating → failure of the windings (repair: 5000–15000 rubles).
- Increased power consumption (up to 30% above normal).
- Product spoilage due to unstable temperature.
- Short circuit (in rare cases - risk of fire).
For example, in refrigerators Nord and Snaige with mechanical relays A common problem is contact sticking. If the part is not replaced on time, the compressor burns out in 1–2 weeks. In electronic relays (LG, Samsung), another malfunction is typical - failure of the thermistor, which leads to constant operation of the motor and its overheating.
The average "life" of a refrigerator with a faulty relay is from 2 weeks to 3 months, depending on the model and operating conditions.
FAQ: Frequently asked questions about refrigerator relays
Is it possible to replace the relay yourself if you have no experience?
Yes, but only if you are sure of the diagnosis. To replace you need:
- New relay (exactly the same model!).
- Screwdriver (Phillips or flathead).
- Mulmeter (for checking contacts).
Difficulty: 3 out of 10. The main thing is not to mix up the wires when connection.
Why did the new relay burn out again after a month?
Probable reasons:
- Voltage surges in the network (install a stabilizer).
- Compressor malfunction (check the winding resistance).
- Poor contact in the connectors (oxidation or weak fixation).
How to check the relay with a multimeter?
Switch the multimeter to resistance measurement mode (200 Ohms). Touch the probes to the relay contacts:
- Between
CandS: it should be 20–40 Ohm. - Between
CiR: 10–20 Ohm.
If the readings differ greatly, the relay is faulty.
What to do if the relay clicks, but the compressor does not start?
This is a sign:
- Open winding of the compressor.
- Malfunction of the starting capacitor (if your model has one).
- Interturn short circuit in the motor.
Diagnostics of the compressor is required.
Where to buy a relay for an old refrigerator (for example, "ZIL" or "Minsk")?
Options:
- Specialized spare parts stores (for example, "Rembyttekhnika").
- Avito/Yula - often sell used parts from Soviet refrigerators.
- Universal relays (for example, RBM-1 or DANFOSS 103N0010), but the fastenings need modification.