Common Reasons Your Fridge Isn’t Cooling Properly

It’s a common and frustrating question, especially in hot states like Texas: Why is my refrigerator not cooling?

At HomeFix Appliance Repair, we’ve been serving Houston and surrounding areas for years, diagnosing and repairing refrigerators of all types and brands. We want to share our expertise to help you understand the possible causes of a non-cooling refrigerator, ways to diagnose the issue, and when you might need professional repair.

1. Faulty Compressor or Start Relay Issue

One of the most frequent causes of a warm refrigerator is a non-working compressor. You may notice that:

• The interior light is on.
• You hear noises from the back of the fridge (likely from the condenser fan).
• The inside of the fridge is warm.

A common culprit is a faulty start relay. Since relays have mechanical parts, they tend to wear out over time, preventing the compressor from starting. However, since compressors operate quietly, you might confuse the condenser fan noise for compressor activity.

How to Diagnose:

1. Access the compressor (typically located at the back, near the bottom of the fridge).
2. Listen carefully to see if the compressor is vibrating or making a low humming sound.
3. Use a non-contact infrared thermometer to check the compressor’s temperature (normal range: 80-120°F).
4. If unsure, carefully touch the compressor using a gloved hand—if there is no vibration, the compressor is likely not running.

⚠ Safety Warning: Be cautious when working near moving parts like the condenser fan. The compressor can also get extremely hot, so using a non-contact thermometer is the safest approach.

Solution:

If the compressor is not running but the condenser fan is, replacing the start relay may solve the issue. However, if the compressor still won’t start, it may need professional diagnosis or replacement.

2. Frozen Evaporator Coils in the Freezer

If your defrost system is not working, the evaporator coils inside the freezer can become covered with frost or ice, blocking airflow and preventing proper cooling in both the freezer and fridge sections.

How to Diagnose:

1. Remove the evaporator cover in the freezer.
2. Check if the coils are frozen over.
3. If they are completely encased in ice, your defrost system is likely malfunctioning.

Solution:

Fixing a broken defrost system requires further diagnosis, which we’ll cover in a separate article. However, you can try a manual defrost by unplugging the fridge for 24 hours to melt the ice. If the problem reoccurs, the defrost heater, defrost thermostat, or control board may need replacement.

3. Low Refrigerant (Freon Leak)

A refrigerator with low refrigerant won’t be able to cool properly, usually due to a freon leak in the sealed system.

How to Diagnose:

1. Remove the evaporator cover in the freezer.
2. Check if the entire coil is evenly covered with frost.
3. If only part of the coil has frost, you likely have a refrigerant leak.

⚠ Warning: Handling refrigerant requires special licensing, and DIY repairs are not recommended.

Solution:

Call a certified refrigeration technician to handle the issue. At HomeFix Appliance Repair, we have extensive experience, including working with high-end refrigerators.

4. Faulty Temperature Sensors (Thermistors)

If the temperature sensor (thermistor) is defective, it may send incorrect readings to the refrigerator’s main control board, causing the compressor to cycle improperly or not turn on at all.

How to Diagnose:

1. Use a multimeter to check the resistance of the thermistor.
2. Compare the reading to the manufacturer’s specifications.

⚠ This requires technical knowledge, so DIY repair is not recommended.

Solution:

A faulty thermistor should be replaced, but since this involves testing electrical components, it’s best to call a professional.

5. Refrigerator Not Cooling Enough

Sometimes, when people say “my fridge is not cooling,” they mean it is cooling, but not as well as before. For example:

• A month ago, your ice cream was rock solid, but now it’s softer than usual.
• The fridge is colder than room temperature but not as cold as it should be.

There are over 10 possible reasons for weak cooling, and accurate diagnosis requires experience and knowledge of refrigeration systems.

However, as a user, you can do the following:
✔ Check condenser coils for dust buildup – pet hair and dust can clog them, reducing cooling efficiency.
✔ Ensure proper airflow inside the fridge – avoid overloading shelves, as this blocks air circulation.
✔ Schedule annual maintenance – just like cars need servicing, so do refrigerators.

Need a Professional Refrigerator Repair in Houston?

If you live in Houston, Katy, Sugar Land, Pearland, The Woodlands, or Cypress, we can:
✔ Diagnose the issue correctly
✔ Repair your refrigerator efficiently
✔ Advise if buying a new fridge is a better option