How to understand that the starting relay on the refrigerator is not working: 7 signs and testing instructions

Did the refrigerator suddenly stop freezing, the motor hums but does not start, or are there rhythmic clicks from the back panel? In 80% of such cases, a small but critical element of the cooling system is to blame. This part is responsible for starting the compressor, and its failure paralyzes the operation of the entire unit. The problem is that symptoms of a failed relay are often confused with a failed thermostat, compressor, or even electronics. In this article, we will look at how starting relay - a small but critical element of the cooling system. This part is responsible for starting the compressor, and its failure paralyzes the operation of the entire unit. The problem is that symptoms of a failed relay are often confused with a failed thermostat, compressor, or even electronics. In this article we will look at how to accurately determinethat it is the relay that is to blame - without disassembling the refrigerator and expensive diagnostics.

You can check the relay yourself in 15 minutes, having only a screwdriver and a multimeter on hand (or even without him!). We have collected unique signs of breakdownthat are not described in standard instructions - for example, how to distinguish a “dying” relay from a burnt-out compressor by sound, or why refrigerators Indesit and Atlant with electronic control behave differently than models Samsung with a mechanical thermostat. And at the end of the article there is a checklist for quick diagnostics and answers to questions that users ask most often.

What is a starting relay and why does it break

A starting relay is electromechanical or electronic devicethat briefly supplies current to starting winding of the compressor, helping it overcome the inertia of rest. Without a relay, the motor simply will not be able to start: it will not have enough “push”. Two types of relays are used in refrigerators:

• 🔌 Induction (mechanical) - with a coil and a movable core. Installed on Soviet and early imported models (Biryusa, ZIL, Stinol old model).
• 💻 Electronic (posistor) —with a thermistor that heats up and opens the circuit. Modern standard for LG, Samsung, Beko.

Relays fail for three main reasons:

1. Natural wear —contacts burn from sparking, the spring loses elasticity (relevant for mechanical relays after 5–7 years of operation).
2. Voltage drops - surges in the network above 240 V lead to breakdown of the winding or “sticking” of contacts.
3. Compressor overheating - if the motor is running with an overload (for example, due to a freon leak), the relay operates more often and wears out faster.

In refrigerators with a system No Frost the relay breaks less often - thanks to the stable operation of the fans and the uniform load on the compressor. But in models with drip defrosting (for example Atlant MXM-1708), the relay suffers more often due to on/off cycles.

7 signs of a faulty starting relay

The main difficulty is that the symptoms of a relay failure coincide with malfunctions of the thermostat, compressor or control board. But there are unique “markers”that will help to distinguish the relay:

Pay special attention to the nature of the clicks:

• 🔊 Single click when plugged in is normal (the relay has worked).
• 🔊 Multiple clicks in a row —the relay is “loop” due to a broken winding or burnt contacts.
• 🔊 Click + humming, then silence —the relay worked, but the compressor did not start (possibly due to an interturn short circuit in the motor).

How to check the starting relay without instruments

If you don’t have a multimeter at hand, you can diagnose the relay “by ear and touch.” This method works for 70% of household refrigerators:

Disconnect the refrigerator from the mains for 10 minutes (let the relay cool down)|

Turn on the refrigerator and listen: there should be one click and the compressor starts|

If there are several clicks and the motor does not hum, the relay is faulty|

Touch the relay body: if it is burns your hand the contacts are stuck or broken|

Check whether the lights inside the refrigerator are on (if not, the problem is in the power supply, not in the relay)-->

For mechanical relays there is another test: gently tap the relay body with a screwdriver during the clicks. If after tapping the compressor starts, there is a relay inside the contacts burned out or the spring has weakened. This is a temporary solution (the refrigerator can work like this from several hours to a week), but the relay still needs to be replaced.

⚠️ Attention: Do not try to disassemble the relay yourself - in mechanical models the spring is energized and can shoot! Electronic relays are non-separable (filled with compound).

Checking a relay with a multimeter: step-by-step instructions

For accurate diagnostics, you will need a multimeter (even the cheapest model for 300–500 ₽will do). Before checking be sure to disconnect the refrigerator from the network and remove the relay from the compressor (usually it is secured with latches or one screw).

On the relay body there are 3–4 contactsmarked with the letters:

• S (Start) - starting winding,
• R (Run) - working winding,
• C (Common) - common contact,
• N (Neutral) - neutral (not available in all models).

If there are no markings, take a photo of the location of the wires before removing the relay!

How to find contacts if there are no markings?

In mechanical relays, contacts S and R are usually located nearby, and C -separately. In electronic relays, the contact is often highlighted in color (blue or black wire). data-i="172">Set the multimeter to mode N often highlighted in color (blue or black wire).

Check procedure:

1. Continuity of compressor windings (to prevent it from breaking):
   • Set the multimeter to 200 Ω.
   • Measure the resistance between C and R - it should be 15–40 Ω.
   • Measure between C and S - there should be 20–50 Ω.
   • Between R and S - the resistance should tend to infinity (break).

⚠️ Attention: If the resistance is between R and S yes - the compressor is faulty (turn-to-turn short circuit), and the relay has nothing to do with it.

Checking the relay:

• For mechanical relay: connect the multimeter to mode 200 Ω to contacts C i R. When turning the relay upside down, the resistance should change from 0 to ∞ (this is the spring triggered).
• For electronic relay: check the resistance between C and S - in a cold state it should be ∞, in a hot state (after work) - 0 Ω.

If the relay does not pass at least one of the tests, it needs to be replaced. The cost of a new relay for popular models (Atlant, Indesit, Samsung) - from 500 to 1500 ₽.

What to do if the relay is faulty: repair or replacement

Mechanical relays can theoretically be repaired - clean the contacts, bend the spring or replace the coil. But in practice, this is unprofitable:

• 🔧 Repair cost (taking into account the work of the master) is comparable to the price of a new relay.
• ⏳ Warranty for a repaired relay - 1-2 months (for a new one - 1-2 year).
• ⚡ Risk of repeated failure — 60% of repaired relays fail within a year.

Electronic relays for repair not subject to —they are filled with compound and can only be replaced entirely. When purchasing a new relay, pay attention to:

• 📌 Refrigerator model —relays must match in current and type (for example, RL3-1/OVL for Indesit or RBM-1 for Atlant).
• 🔌 Type of fastening —some relays are mounted with a screw, others with latches.
• 💡 Presence of thermal protection —modern relays often have a built-in fuse that turns off the compressor when overheated.

You can replace the relay yourself:

1. Disconnect the refrigerator from the network.
2. Remove the back cover (if there is one).
3. Disconnect the wires from the relay (it is better to take a photo of the circuit connection!).
4. Remove the relay from the compressor (unscrew the screw or press out the latches).
5. Install a new relay and connect the wires in the reverse order.

1) Correct connection of the wires (especially S i R).

2) Voltage in the socket (should be 220–230 V).

3) Condition of the compressor (it may have burned out due to prolonged operation with a faulty relay).-->

Frequent diagnostic errors and how to avoid them

Even experienced technicians sometimes make mistakes when checking relays. Here are the most common mistakes:

• 🔌 Checking the relay without turning off the compressor —it's dangerous! Capacitors in the circuit can retain charge and cause an electric shock.
• 📏 Ignoring contact markings - if you mix up S and R, the compressor will not start, and the relay may burn out.
• 🌡️ Checking the electronic relay in a cold state —the posistor when cold shows an open circuit, which is normal. Heat the relay with a hairdryer (up to 60°C) and repeat the measurement.
• 🔊 Confusion of the clicks of the relay and thermostat —the thermostat clicks are usually quieter and less frequent (once every 1-2 minutes). The relay clicks synchronously with attempts to start the compressor.

Another typical mistake - purchase of a universal relay instead of the “native” one. Universal relays (for example RBM-4 or RLS-4) are suitable for many models, but may not take into account the characteristics of a particular compressor. For example, in refrigerators Liebert with inverter compressors, specialized relays with soft start are used - a universal one simply will not work.

When the relay is not to blame: other causes of such symptoms

If you checked the relay, but the refrigerator still does not work, the problem may be:

Part	Symptoms	How to check
Thermostat	The refrigerator does not turn on at all (no clicks, no lights).	Short the thermostat wires directly - if the compressor starts, the thermostat is faulty.
Compressor	The relay clicks, but the motor does not hum (or it buzzes and immediately turns off).	Ring the windings (see the section on the multimeter). If the resistance between R and S is not ∞, the compressor is burned out.
Control board	There is an error on the display (E1, ER IF), the refrigerator turns on chaotically.	Check the voltage at the output of the board (should be 220 V at the start command).
Starting capacitor	The compressor starts, but after 1-2 seconds stalls.	Test the capacitor with a multimeter (resistance should drop from ∞ to 0).

In refrigerators with a system No Frost similar symptoms can be caused by a malfunction defrost timer or evaporator sensor. If the fan works, but the compressor does not start, check these elements.

FAQ: Answers to frequently asked questions

Is it possible to start a refrigerator without a start relay?

No, the compressor will not be able to start without a relay - it will not have enough starting current. As a last resort, you can close the contacts (only for mechanical relays!), but this is dangerous: the compressor can burn out from overload. This method is only suitable for testing - do not leave the refrigerator operating in this mode for more than 1-2 minutes! temporarily close contacts C And R (only for mechanical relays!), but this is dangerous: the compressor can burn out from overload. This method is only suitable for testing - do not leave the refrigerator operating in this mode for more than 1-2 minutes!

How much does it cost to replace a relay in a service center?

The cost of replacing a relay in workshops:

• Moscow/St. Petersburg: 1500–2500 ₽ (excluding spare parts),
• Regions: 800–1500 ₽.

Urgent visit of a specialist (on the day of contact) can increase the price by 30–50%. If the refrigerator is under warranty, the repair is free (but the warranty usually does not cover breakdowns due to power surges).

Why did the new relay burn out quickly?

There are three possible reasons:

1. Faulty compressor —if there is an interturn short circuit, it overloads the relay.
2. Low voltage in the network (below 190 V) - the relay operates more often, trying to start the engine.
3. Poor quality relay — cheap analogues (especially without thermal protection) fail in 1–3 months.

Before installing a new relay, check the voltage in the outlet and the condition of the compressor!

How to extend the life of the starting relay?

Four simple rules:

• 🔌 Use voltage stabilizer (especially if your light blinks frequently).
• 🧊 Do not overload the refrigerator with food - this increases the load on the compressor and relay.
• 🧹 Regularly clean the condenser (grid on the back wall) from dust - overheating shortens the life of the relay.
• ❄️ Defrost the refrigerator with a drip defrosting system at least once every 6 months (in No Frost — once a year).

Where to buy an original relay for your refrigerator?

Original relays are sold:

• B branded service centers (for example, for Samsung or LG).
• On specialized sites (for example, Spare parts for refrigerators, All-Zap).
• In electronics stores (for example, Chip and Deep, Platan) - there are often universal relays Danfoss or Emerson.

⚠️ Attention: When purchasing, check not only the model of the refrigerator, but also compressor serial number (located on its body). Relay for compressors Secop (formerly Danfoss) interchangeable! Embraco not interchangeable!