AC Not Cooling Properly? Here’s What Might Be Going Wrong

There’s nothing worse than turning on your air conditioner in the middle of a Utah summer and realizing it’s not cooling your home. The unit might be humming, the fan may be blowing—but your house still feels warm and muggy.

If this sounds familiar, you’re not alone. Every summer, we receive dozens of calls from homeowners across Logan, Cache Valley, and nearby towns with the same question: “Why is my AC running but not cooling?”

Here’s a breakdown of the most common reasons your air conditioner isn’t working properly—and what you can do about it.

1. Thermostat Issues

Let’s start with the obvious. Sometimes the problem isn’t your AC—it’s your thermostat.

• It may be set to “Fan” instead of “Cool”
  
• The batteries could be low or dead
  
• You may have incorrect temperature or mode settings
  
• Smart thermostats might be disconnected from Wi-Fi or sensors
  
  

Quick Fix: Double-check settings and change batteries. If the problem persists, you may need a new thermostat or calibration.

2. Dirty or Clogged Air Filters

This is the #1 cause of reduced airflow—and it’s also the easiest to fix. When your air filter is clogged with dust and debris, your system can’t circulate air efficiently.



Results include:

• Poor airflow from vents
  
• System overheating
  
• Ice forming on coils
  
• Higher energy bills
  
  

Solution: Change your air filter every 1–3 months, especially during summer when your system works harder.

3. Low Refrigerant Levels

Refrigerant is the chemical that cools the air inside your AC unit. If your system is low on refrigerant—or has a leak—you may notice:

• Warm air blowing from vents
• Long cooling cycles
• Ice on your outdoor unit or lines
• Hissing or bubbling noises

Warning: Refrigerant isn’t a DIY fix. Call a licensed HVAC technician to inspect for leaks, recharge your system, and restore proper cooling.

4. Dirty Condenser Coils

Your outdoor condenser unit releases the heat that your indoor unit removes. If the condenser coils are covered in dirt, grass, or debris, it can’t release heat effectively, which means your system can’t cool your home properly.

Fix: Turn off power to the unit and rinse coils with a hose, or schedule a professional cleaning for deep buildup or corrosion.

5. Blocked or Leaky Ductwork

Ductwork is like the highway for your cool air. If ducts are:

• Crushed or kinked
• Leaking air into the attic or walls
• Obstructed by debris

…then your air may never make it to your living space.



Fix: We offer duct inspections and sealing services to restore airflow and efficiency.

6. Frozen Evaporator Coils

If your AC is blowing warm air or shutting off suddenly, it could be due to frozen coils, which are often caused by:

• Dirty filters
• Low refrigerant
• Restricted airflow

Fix: Shut the system off and call a technician to safely thaw and diagnose the root cause. Never chip away ice—it can damage components.

7. Electrical Issues or Blown Capacitors

If your AC unit turns on but doesn’t cool, or starts and stops erratically, the problem may be electrical. Capacitors, fuses, and relays can wear out and disrupt system function.



Fix: Call a pro. Electrical repairs require proper tools and expertise—DIY attempts can be dangerous.

8. Undersized or Oversized System

If your home was recently remodeled or your AC was poorly sized at installation, it may be:

• Too small to keep up with cooling demand
  
• Too large, cycling too quickly, and not dehumidifying properly
  
  

Fix: We can assess system sizing and recommend right-fit solutions for comfort and energy savings.

Bonus Tip: Check for External Blockages

Shrubs, fencing, and debris can restrict airflow around your outdoor condenser unit. Make sure it has at least 2–3 feet of clearance on all sides.

Real-Life Fix from Logan, UT

A homeowner in Smithfield called us in July, saying their AC was running constantly, but the house wouldn’t cool below 78°. We found a clogged filter, a frozen coil, and low refrigerant. After replacing the filter, thawing the coil, and sealing a refrigerant leak, their system was cooling perfectly—just in time for a 95° weekend.

Stay Cool All Summer with Four Seasons Heating & A/C

If your AC isn’t cooling like it used to, don’t sweat it. Our certified technicians at Four Seasons Heating & A/C are here 24/7 to diagnose the issue, explain your options, and get your system back on track.