Samsung Refrigerator Not Cooling

Autor: nicO (e 3 outros contribuidores)

You may want to take a look at the component diagrams on our How a Refrigerator Works page, which will help you understand where all of the major components are so that you can more easily locate them.

It's also important to perform regular fridge maintenance. Keep it running well with these tips.

Before removing and replacing or continuity testing electrical components, power down the fridge. This will prevent damage to the components and prevent you from being electrocuted.

If the fridge is pulled away from the wall, remove the plug.
Otherwise, find the fridge’s circuit breaker in your breaker box and turn the circuit off.
Check that the lights are off in in the fridge when you open the door

The evaporator fan blows cold air around the freezer. Too much food or incorrectly placed food will block the vents and prevent proper temperature regulation. The refrigerator vents allow for airflow between the fridge and freezer compartments. The following tips may help your freezer maintain a safe temperature:

Locate your evaporator fan and move frozen items further away.
Unblock the vents. A rule of thumb for frost prevention is to stock enough food to fill the freezer while keeping an inch of space between the food and the walls.

If your refrigerator has a knob or dial that sets the temperature, check it out. Verify it is set on cold and hasn't been bumped or shifted positions. Use a thermometer if you don't have a digital thermostat display. The freezer should be around 0°F (-18°C); the fridge around 34°F(2°C)

You should try to reset the power to your fridge.

Unplug your refrigerator. If the plug is too hard to reach, switch the circuit breaker off.
Wait 5 minutes before returning power to the fridge.
This will reset your fridge but some modes need to be manually disabled. (see the next step)
Monitor temperature over the next 24 hours.

Your refrigerator may have inadvertently been placed in a demo mode where the compressor doesn't run and it doesn't get cold, but all the interior lights work and possibly even the fans.

Here is a link to a Samsung document for Entering and Exiting Demo Mode

Your fridge will not work if its power has gone out. Make sure the interior lights or exterior control lights are lit. Perhaps the fridge is running but lights are flickering or burned out, which indicates power.

If you seemingly have no power, check the electrical breaker. Reset the breaker in the event of a trip. Find the GFCI outlet and reset it as well.
Still no power? Run an extension to another outlet and test again.
- If another outlet works, then there's an issue with your house's electrical. Consider calling an electrician.
- Still no power in another outlet? Your fridge has an electrical issue. Call an appliance technician.

Refrigerators perform best when located inside a home and at around 70°F (21°C). Locations considerably above this temperature like 90°F (31°C) affect the cooling capacity, and the fridge may not cool sufficiently.

When in an unheated garage where the temperature drops below 36 degrees Fahrenheit (2 degrees Celsius), the refrigerator may shut down and stop cooling. This can lead to food thawing and warming inside the insulated fridge, especially in the freezer portion.

Additionally, a fridge located in a warm room, under the sun, or near hot appliances like a range or oven can experience difficulties cooling effectively.

Door seals are gaskets for your fridge, and as they age and fall apart, cool air escapes through the cracks in door seals.

Inspect your door seals, then clean or replace if necessary.
Find door seals and gaskets Refrigerator Gaskets and Seals.

At the backside and bottom of your fridge are the condenser and its coils. Refrigerant passes through the coils which dissipates heat during the cooling cycle. As dust and debris pile onto the coils, the fridge becomes less efficient the fridge must work hard to cool down.

|Pull your fridge out and inspect the coils.
- Your fridge may have an anti-tip bracket and can only be removed by pulling straight out from the wall.
Clean dust off condenser coils and fan with a stiff condenser coil brush and vacuum.
Work carefully during this task and avoid bending or damaging the tubes.

A fridge out of level may refuse to cooperate and cool effectively.

Start by adjusting the front feet. Use a bubble level and correct any side-to-side wonkiness in the fridge.
Tilt the fridge back slightly. This will allow doors to close on their own, and increase efficiency.

The condenser fan draws air over the compressor and through the condenser coils. If the fan motor isn't working normally, then the fridge won't cool properly.

Check the fan blade for physical obstructions
Rotate the fan by hand. If it doesn't spin freely, replace the motor.
If it spins freely, test the motor for continuity. Replace the condenser fan motor if the continuity test fails.

The evaporator fan draws air over the cooling coils and circulates this air within the fridge and freezer compartments. The evaporator fan should be running as long as the compressor motor is running. If your fridge only has one evaporator fan motor it's located in the freezer compartment. When the fan fails it won't circulate the cold air to the refrigerator. In this event, the freezer may still get somewhat cold while the refrigerator stays warm.

Check the fan blade for physical obstructions.
Note: The fan may not be running if it's iced up due to the defrost system failing
Check for ice buildup. Use the freezer building ice guide
Rotate the fan by hand. If it doesn't spin freely, replace the motor.
If it spins freely, test the motor for continuity. If the continuity test fails, replace the evaporator fan motor. If your fresh food evaporator fan has a problem, here's a guide to replace that.
An unusually noisy motor should be replaced as well.

The refrigerator monitors the temperature inside the fresh food compartment with a device called a thermistor. The resistance of the thermistor is what is monitored by the main control board. If the thermistor is out of spec, the control board will sense the temperature incorrectly.

At 20°C (77°F), the resistance is around 5 kΩ for Samsung thermistors.
A quick procedure is to power down the fridge and then unplug and re-plug, in turn, each connector on the control board. Then try starting the fridge again.
The thermistor resistance on the refrigerator is best checked at the control board. This allows you to "see" what the control board is seeing.

A service manual for your model is the best guide for which connection to check on the main control board. You can try looking for the tech sheet for your refrigerator. It may be near the compressor or tucked near the front grille.

The example page actually states that if you have an open circuit, you have to replace the refrigerator. Kind of drastic, but the issue is that the wiring harness for the thermistor may be buried in the insulation of the fridge. So, if there's a broken wire, there's almost nothing you can do about it. See below in Help For a Faulty Thermistor for more on this and other checks to run.

Remove the Thermistor.
There's often one thermistor in the freezer, and one in the fresh food compartment.
Grab a multimeter and continuity test the thermistor.
If the value isn't around 13kΩ at 0°C (32°F), replace your temperature sensor.

If the refrigerator is not cold enough, the temperature control board might be defective. The temperature control board provides the voltage to the fan motors and compressor. These boards are often misdiagnosed. Check other components to be certain this is the cause of the problem. These boards will be found on simpler models that usually don't have digital displays.

If the display LEDs or Temperature Setting button are not responding, it could signal that the board has failed.
Remove the board from the fridge and reconnect it. Verify the wire connections are secure.

If the capacitor has failed, the compressor will not be able to start and run as it should. Most newer refrigerators use a run capacitor, which stays in the circuit and improves the energy efficiency of the compressor. Some older refrigerators may have a start capacitor, which functions just at startup. These are not as common.

You may be able to tell what kind you have by looking at a couple of factors. Many run capacitors are polymer-type capacitors with a small rectangular block shape. There are cylindrical run capacitors, but they are less common (some LG fridges have them). The capacitance values of run capacitors tend to be smaller on refrigerators, something between 10 and 22µF (µF stands for microfarads, also abbreviated MFD).

A Typical Run Capacitor

Safely remove the capacitor and discharge with a discharge tool.

On smaller capacitors, you can use a screwdriver with an insulated handle to discharge it. But be careful as capacitors increase in size.

Test the capacitor with a capacitance meter; replace it if the value measured is outside the tolerance listed on the capacitor (usually +/- 5-10%).

A very quick functional check for a capacitor is to set your multimeter to the continuity function with the beeper on. Connect the capacitor to the leads for a few seconds. Then, swap the leads to the opposite terminals. If the capacitor is at least storing some charge, you should get a short beep. This will not tell you if the capacitance is correct, only that the capacitor will store charge.

When you replace a capacitor, get the exact type of the existing capacitor and the same capacitance value. You can safely use a capacitor with the same or higher voltage rating than the original.

If everything checks out, go to the next item.

The overload relay is a protection device in the compressor circuit. It is often combined with the start relay and plugged directly into the compressor's side.

Compressors on some newer fridges may not have this device, especially those that use an inverter to control the motor. The inverter handles the overload function.

If the fans are running and your compressor won’t start, or if you hear a clicking sound from the unit follow the troubleshooting below. The guides below are for a Whirlpool device, but the Samsung is similar.

Safely remove the start relay assembly.
Check the overload relay for signs of overheating or arcing.
- This may be a hot module, burnt, or rattles when shaken.
Check for continuity with a multimeter.
- Flip the unit over and test again. If there's no continuity, replace the unit.

The start relay is a small device mounted to the side of the compressor. It provides power to the start winding for a split second at startup to get the compressor going. If the start relay is defective, the compressor may run intermittently or more likely not at all, and the refrigerator will not get cold enough. The start relay should be replaced if defective.

Safely remove the start relay assembly. This guide shows a Whirlpool unit, but the process is similar.
Test Start Relay with a multimeter. View the video above and verify if your start relay is functioning.
Replace the relay if it fails the testing or has a burnt odor. Depending on your start relay, you may have to test the start capacitor and overload relay first and use a process of elimination. If the other two components pass continuity tests, and your compressor isn't starting, try replacing your start relay.
Find switches Refrigerator Switches.
Find start relays Refrigerator Start Relays

Modern refrigerator compressor technology has shifted from split-phase motors to brushless DC motors which usually are very like a 3-phase AC motor.

This means that instead of the start relay assembly normally attached to the compressor pins — the start relay, overload relay, and overload capacitor — there is now a sealed motherboard and many wires. The inverter board modulates the power supplied to the compressor, allowing for more efficient operation.

This new technology is harder to test, so follow this helpful video.

The inverter board must be tested by the process of elimination.

First, test the input voltages. The inverter board will have both a 120V AC main power supply voltage and a 4-6V DC voltage from the main control board. Remember to make all voltage measurements with everything connected.
If one of these voltages is missing, the inverter board will not work.
- Backtrack to find the issue. You could have a faulty wire harness connector, a bad motherboard, or another issue.
Second, follow the compressor continuity testing from above to verify your compressor isn't shorted and is okay.
- If the compressor is fine, and the board input voltages are fine, then your inverter board has failed and needs replacing.

If the compressor is very noisy when you start it up, it may have been damaged in transit, or you could just have a faulty compressor.

If the overload relay, start relay, and capacitor pass continuity testing, then you may have a defective compressor.

Test the compressor for continuity by following the video above.
Resistance values vary based on the compressor.
Values outside of the range or a short to ground will mean replacing the compressor, which is a costly repair.
If your fridge is more than a few years old, you may be better off replacing the fridge instead of the compressor.
Find replacement compressors for your refrigerator here.

If there is a refrigerant leak, the fridge won't be able to maintain a proper temperature. Your compressor is likely running non-stop.

Contact a service technician to refill or replace your coolant or compressor. This may result in replacing the entire fridge.

Main Control Board Failure

Finally, the main control board might be defective if the refrigerator doesn't get cold enough. This is a costly repair but one that is still within reach for DIY.

Since thermistors do fail, you should make an extra check at the thermistor location itself, especially if you read an open or a short. You can remove the thermistor from the small cage or grille that holds it. This will allow you to access a pigtail attached to the thermistor. You can then isolate the thermistor and see if the defect is in the thermistor or in the refrigerator's wiring.

Some thermistors may have connectors that you can pull free to access in the fresh food or freezer compartments, so check before cutting wires.

If you make this check, you may need to cut the wires to the thermistor. You will then measure the thermistor directly. If it is in spec, but the control panel reading was open, you have an internal wiring problem that will be essentially impossible to fix. The same goes for a correct reading at the thermistor but a short reading at the control panel.

If your thermistor reads shorted or open itself and that matches the control panel reading you got, you may choose to replace the thermistor. You will have to make waterproof splices in the wiring when you connect the new thermistor since it will be subject to moisture.