Resolve Power Cycling Issue on Samsung RF21R5301SG Refrigerator

When a Samsung RF21R5301SG refrigerator keeps shutting off and restarting on its own, you are likely dealing with a power cycling problem. Power cycling can be caused by electrical fluctuations, compressor issues, thermostat settings, or internal faults. The following guide walks you through the most common causes and how to fix them. Follow each step carefully and use the safety precautions before you begin any work on your appliance.

Understand the Symptoms

Before you dive into repairs, identify the exact symptoms. A refrigerator that turns on, runs for a short period, then shuts off and restarts repeatedly is exhibiting classic power‑cycling behavior. Other warning signs include:

• Loud clicking sounds at startup
• Inconsistent temperature readings
• The compressor hums but never reaches full power
• The display panel flashes or resets
• The appliance appears to “reset” after a brief pause

If you notice any of these signs, it is time to investigate.

Safety First

Always follow these safety rules before touching the fridge:

1. Unplug the unit from the wall outlet.
2. Let the fridge rest for at least 15 minutes to allow internal components to cool.
3. If you are uncomfortable working on electrical parts, contact a certified technician.

These steps protect you and preserve the appliance’s warranty.

Check the Power Supply

The simplest cause of power cycling is a bad power connection.

Verify the Outlet

• Use a voltage tester to confirm that the outlet supplies 120 V (or the appropriate voltage for your region).
• If the outlet is on a circuit with a breaker that trips frequently, consider moving the fridge to a dedicated circuit.

Inspect the Power Cord

• Look for frayed wires, scorch marks, or kinks.
• If you spot damage, replace the cord with a matching Samsung part.

Confirm the Plug

• Ensure the plug is fully seated in the outlet. A loose connection can cause intermittent power loss.

Examine the Circuit Breaker and Fuse

A circuit breaker that trips often or a blown fuse can lead to power cycling.

• Locate the breaker box and look for the breaker labeled for your kitchen or refrigerator circuit.
• Flip the breaker off and on to reset it.
• If it trips again immediately, the circuit may be overloaded; add the fridge to a separate circuit.

Evaluate Door Seals and Gaskets

A compromised door seal can make the compressor work harder, leading to power cycling.

• Close the fridge door firmly and watch for any gaps.
• Clean the gasket with warm, soapy water and a soft cloth.
• If the seal is cracked, replace it with a new gasket from Samsung.

Review Thermostat Settings

An incorrect thermostat setting can trigger the compressor to cycle on and off rapidly.

• Open the temperature dial inside the fridge compartment.
• Set it to the middle position (typically 4 on a 1‑7 scale).
• Observe if the cycling stops after adjusting the setting.

Reset the Refrigerator

A simple reset can clear temporary faults that cause power cycling.

1. Unplug the refrigerator.
2. Wait 30 seconds.
3. Plug it back in and observe the startup sequence.

If the issue persists, move to the next step.

Inspect the Compressor

The compressor is the heart of the cooling system. A failing compressor may shut down to protect itself.

• Listen for a slow, uneven hum or a sudden spike in sound.
• If you notice any irregular noises, contact Samsung service.

Do not attempt to replace the compressor yourself; this requires specialized tools and expertise.

Clean the Condenser Coils

Dust and debris on the condenser coils can reduce cooling efficiency and force the compressor to cycle.

• Locate the condenser coils on the back or bottom of the fridge.
• Use a coil cleaning brush or a vacuum with a brush attachment to remove dust.
• Reattach the coils and re‑plug the unit.

Clean coils should be maintained at least twice a year.

Check the Evaporator Fan

A malfunctioning evaporator fan can cause uneven temperature distribution and trigger power cycling.

• Remove the back panel of the freezer compartment.
• Look for a fan that is spinning or appears jammed.
• If the fan motor stalls or the blade is damaged, replace the fan.

Inspect the Internal Temperature Sensor

The fridge relies on a temperature sensor to decide when to turn the compressor on or off.

• Use a multimeter to test the sensor resistance at room temperature.
• Refer to the service manual for the correct resistance value.
• If the sensor reads an abnormal value, replace it.

Look for Error Codes on the Display Panel

The RF21R5301SG may show specific codes that indicate the root of the problem.

• Note the code when it appears.
• Search the Samsung service portal or the refrigerator’s manual for the code description.
• Follow the recommended action for that code.

Test the Power Circuit with a Multimeter

If all other checks fail, you may need to test the power circuit inside the fridge.

• Set a multimeter to voltage and measure across the compressor terminals.
• Confirm that the compressor receives 120 V.
• A lack of voltage indicates a wiring issue that requires professional repair.

Consult Samsung Service

When the above steps do not resolve the problem, you have likely identified a deeper fault.

• Call Samsung’s customer service hotline.
• Provide them with the model number and the symptoms.
• Schedule a technician visit if the unit is still under warranty or if a professional diagnosis is required.

Samsung technicians can diagnose compressor, motor, and PCB failures safely.

Maintenance Tips to Avoid Future Power Cycling

• Keep the fridge and freezer doors closed for as short a time as possible.
• Clean the coils every six months.
• Avoid overloading the fridge; excess weight forces the compressor to work harder.
• Store foods in sealed containers to reduce humidity and door opening time.

Regular maintenance keeps your refrigerator operating smoothly.

Quick Reference Checklist

• Power outlet – correct voltage
• Power cord – intact, no frays
• Breakers – not tripping
• Door gasket – seal intact
• Thermostat – mid‑setting
• Reset – 30‑second unplug
• Compressor – smooth hum
• Coils – dust free
• Fan – spinning freely
• Sensor – correct resistance
• Error codes – addressed

Final Thoughts

Power cycling on the Samsung RF21R5301SG can stem from a variety of issues, from simple wiring problems to complex compressor faults. By systematically checking the power supply, temperature settings, door seals, and internal components, you can often pinpoint the cause and restore reliable operation. If the problem persists beyond your troubleshooting efforts, reach out to Samsung service professionals. Regular cleaning and maintenance will reduce the likelihood of future power‑cycling episodes and extend the life of your refrigerator.