The temperature in a refrigerator is what makes it a working appliance. But if your refrigerator temp goes up and down, it is crucial to find a lasting solution.
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Is It Normal for a Refrigerator Temperature to Fluctuate?
Temperature fluctuations in a refrigerator are pretty normal. When the refrigerator runs a cooling cycle, the compressor turns off for some minutes for the defrost cycle to run. Not all refrigerators have automatic defrost systems, but the compressor still shuts off after a time. During that time, the temperature rises. Then, the cooling cycle begins to run again, and so runs the refrigeration cycle.
Some refrigerators are better able to handle temperature fluctuations because they are of better quality. Pricey refrigerators are designed to control such fluctuations and keep the temperatures stable. Typically, a refrigerator’s temperature should be between 37 degrees and 44 degrees Fahrenheit, and the freezer should be between 0 degrees and 5 degrees Fahrenheit, at most, 10 degrees.
However, the fluctuations are no longer normal if the internal temperatures swing between extremes too frequently. If you find the temperatures outside the above-mentioned ranges, something is causing it.
A few factors affect the fluctuations, no matter the model or cooling capacity. Such factors include the leaky or dirty door gasket, amount of items in the refrigerator, frequency of door opening, thermostat, dusty condenser coils, and improper temperature settings.
Refrigerator Temp Goes Up and Down – What to Do
If you find that your refrigerator temperature goes up and down, check the following:
1. Door Seal
Run your hand down the length of the door seal to check for cold draughts. It is a clear sign the seal is no longer working as it should. So, replace it. But if you feel nothing, place a dollar bill between the seal and frame. Shut the door and try pulling the dollar bill out. Replace the seal if you can.
A worn-out door seal will easily let cold air out and warm air in. It causes the refrigerator’s internal temperature to fluctuate, tending more towards warm than cold. Therefore, the seal must be one of the first things to check.
If the above does not apply, check to see if the seal is dirty or loose. Dirty seals keep refrigerator doors from tightly sealing, causing the temperature to rise with the loss of cold air. The same applies to loose seals. But cleaning the seal or pushing it back into place with a small screwdriver will permanently fix the issue.
2. Door Opening
On the heel of checking the seal is checking how often you open and close the door. Opening it too frequently will also let cold air out, much like a weak door seal. When you close the door, it traps the air inside and causes the temperature to drop too low.
The temperature rises again when you open and hold the door open for an extended period. Limit the number of times you open the door and the length of time you hold it open. It may fix the temperature fluctuation problem.
3. Refrigerator Contents
Keep the refrigerator filled as much as possible. And while you are at it, space the contents; do not place them too close together. Thermal mass helps to stabilize the internal temperature. In other words, you may find fluctuations in refrigerators that are too empty or too full.
Therefore, avoid overstocking the unit so that there is not enough space for air circulation. But do not leave it too empty that the cold air has nothing to cool. It helps to keep it only half-full or three-quarter full.
4. Air Vents
Check the sides and back of the refrigerator to ensure it has enough space to dissipate hot air. If it does not, move the unit about two inches from the surrounding walls. Ensure nothing is blocking the condenser coils, fan, and compressor as they run.
The inability of the refrigerator to expel heat as part of the normal refrigeration process encourages temperature fluctuation. In some cases, the refrigerator may work extra hard to cool to maintain a cool temperature, thereby increasing the flow of cold air and encouraging freezing.
5. Temperature Setting
Improper temperature settings or adjustments may be responsible for the fluctuations. So, check the setting to see if it is correct. You or someone else may accidentally change it. Typically, a refrigerator should be set at 37 degrees Fahrenheit. If it has a freezer, set it at 0 degrees Fahrenheit. A thermostat with single digits should be set at the mid-point for the best results.
If that is not what you see, it is crucial to adjust it correctly. But if the temperature is correct, use a thermometer to determine the exact temperature. Then, lower the temperature setting to decrease and stabilize the temperature if necessary.
6. Condenser Coils
Disconnect the refrigerator from electric power and move it to create space. Unmount the screws that secure the lower back panel in place and remove it. Then, check the state of the condenser coils. If they are noticeably dirty, clean them with a small soft-bristled brush or a vacuum cleaner. Ensure you remove all the dirt and clean the floor around the coils.
Condenser coils play a vital role in how a refrigerator operates. When they are clean, they easily release the heat from the refrigerant so that it does not remain trapped in the unit and affect cooling. However, they cannot perform their duty, causing the refrigerator’s internal temperature to go up and down in an unstable manner. Therefore, keep the condenser coils as clean as possible, cleaning them once or twice every year.
7. Thermostat
Inspect how well you arrange the contents inside the unit; they may be blocking the sensor. If necessary, move items around to create space around the thermostat. Avoid placing cold food or drinks too close to the thermostat will trigger it to turn the cooling system off, even if the refrigerator is not as cold as it should be. On the other hand, placing hot food next to it will cause it to sense that the refrigerator needs cooling, thereby causing the temperature to fluctuate.
It is important to note that the refrigerator’s internal temperature is adversely affected if you store hot food. Leave the food out to cool before storing it. Otherwise, it may cause frost buildup and reduce cooling.
The arrangement of the refrigerator contents can affect the stability of the internal temperature. Items can block the vents or nudge the thermostat out of order. They can also block the sensors, keeping them from correctly reading the temperature. As you move the contents around, the sensors erratically read the temperature, causing the control board to turn the cooling system off and on in an unstable fashion.
There is also the possibility that the thermostat is faulty. So, test it with a multimeter to check continuity if rearranging food does not solve the temperature issue. Replace the thermostat if it has no continuity.
Other Refrigerator Parts to Check
Other refrigerator electrical components such as the evaporator fan may be faulty, causing the temperature to fluctuate. You will find the fan in the same compartment as the evaporator coils. Ensure the blades turn well and have no debris or ice around them. If they are stiff, check the continuity of the fan with a multimeter, and replace it if it has no continuity.
Also, check the evaporator coils while checking the fan. They have frost on them, reducing their capacity to release cold air for the refrigerator. The temperature will fluctuate or the refrigerator will stop cooling at all if the coils are frozen. Manually thaw them by turning the refrigerator off and leaving the door open. You can also use a hairdryer to melt the ice off the coils.
However, be aware that the evaporator coils do not accumulate frost on their own. The defrost system may be malfunctioning. The door seal may also be leaky, letting warm air into the unit, so much so that the defrost system cannot keep up. Therefore, check the door seal, and if it is in good working condition, troubleshoot the defrost system.
If all else fails, hire a certified refrigerator technician to run more diagnostics on the unit and permanently fix any issues.
Check out these other articles…
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Refrigerator Thermistor [How to, Problems & Solutions]
Freezer Does Not Freeze [Issues Solved]
Laying a Refrigerator Down [Critical Information]
How to Bypass a Refrigerator…[Detailed Guide]
Fridge Temperature Keeps Dropping – Quick Fix
Check the following parts if your fridge’s internal temperature keeps dropping:
1. Thermostat
The temperature control thermostat is usually inside the refrigerator. Check to see if it is working. The knob should be at mid-point to keep the fridge at 38 degrees Fahrenheit. Adjust the knob to the middle if it is set at a higher number; the higher the number, the colder the temperature.
Inspect the sensor if the setting is not the source of the problem. Also, inspect the terminals for looseness or corrosion. If none of these applies, check the continuity of the thermostat using a multimeter. Replace the thermostat if you find no continuity. When you replace it, set it to mid-point and wait for the fridge to cool. You can adjust it further if necessary, but you will have to wait 24 hours before doing that.
2. Thermistor
Your fridge will use a thermistor to govern the temperature if it has an electronic control board. A malfunctioning thermistor will affect the cooling capacity of the unit. So, locate the thermistor using the manual. It is a small part with two protruding wires, and it may be on the wall inside the fridge, inside the temperature control housing, or behind a small cover inside the unit.
Locate the refrigerator’s tech sheet in the compressor compartment or on the fridge’s back. Find the correct resistance of the thermistor to the fridge’s temperature. Then, use a multimeter to check the sensor. Replace the thermistor if the resistance is incorrect.
3. Air Damper
You will find the air damper at the top left corner of the fridge or between the freezer and fresh food compartments. There may be a knob to control its closing and opening functions. But use your hand to check its functionality if you find no knob. If the damper does not open and close as it should, it may have loose wiring or be broken. In such a case, replace the damper.
The air damper controls the amount of cold air coming into the fridge from the freezer. In units with single cooling systems, the fridge cools through the cold air that comes from the freezer. So, the fridge will become too cold to the point of freezing if the damper can no longer control the cold air flowing into it. In this case, the damper will be stuck open.
4. Control Board
The problem may stem from the main control board. If that is the case, the solution is not straightforward, especially if your fridge is a newer model with an electronic control board. The fridge’s user manual may have instructions for diagnosing problems with the board, but you can perform a visual inspection to check for burns, arcing, or damaged foil. Otherwise, hire a professional to check the board.
How to Turn the Fridge Temperature Down
With a thermostat, turn the knob clockwise or to your right to lower the temperature. Some thermostats have numbers, ranging from Off to 9 or 0 to 9. The smaller the number, the warmer the temperature. So, if you want the fridge to be colder, move the knob towards the higher numbers or to your right.
On the other hand, turn the knob counterclockwise or to your left to increase the temperature. But if you want the fridge to maintain food-safe temperatures, keep the knob in the middle; most times, that will mean 5.
Recap
If you find a refrigerator temp goes up and down, check the door seal, refrigerator contents, temperature settings, condenser coils, thermostat, evaporator fan, and evaporator coils. One or more of these can cause the temperature to fluctuate.
But remember that temperature fluctuations are pretty normal in refrigerators, though they tend to be minimal. Therefore, if none of the fixes works for a refrigerator temperature that erratically fluctuates, and you have no other solution, employ the services of a qualified technician for further assistance.
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