When your air conditioner is on but refuses to deliver cool air, it’s more than just annoying, it can signal hidden issues that drive up energy bills or lead to costly damage. Rather than Google “Why is my AC running but not cooling?” Learn about the most common culprits and what to do here:
1. Dirty or Clogged Air Filter
A clogged filter chokes airflow, causing the system to work harder while delivering less cool air. It may also lead to ice forming on the evaporator coils, further impairing performance.
DIY fix:
- Check filters monthly; replace standard ones every 1–3 months, or more often if you have pets or allergies.
2. Incorrect Thermostat Settings
Sometimes, the problem isn’t the AC, it’s the settings. If the thermostat is in “Fan On” mode instead of “Auto/Cool”, it may run the fan without cooling. It’s also worth ensuring the thermostat is actually set to “Cool” and the target temperature is below room level.
3. Refrigerant Leak or Low Refrigerant
Refrigerant is essential for heat absorption. When levels are low—often due to leaks—the AC might run but won’t cool properly.
Signs include:
- Hissing or bubbling noises
- Ice buildup on the evaporator coil or refrigerant lines (learn.sensibo.com, Direct Home Services)
- Higher energy usage or AC running constantly
What to do: This requires a licensed technician. They’ll locate the leak, repair it, and recharge with the correct refrigerant.
4. Frozen Evaporator Coils
Restricted airflow—from dirty filters, low refrigerant, or blower issues—can freeze the evaporator coil, stopping cooling entirely.
Steps to take:
- Turn off the AC and let the ice thaw.
- Change your filter and clean any blocked vents.
- If freezing continues, call a professional to check refrigerant levels and blower function.
5. Dirty or Blocked Condenser Coils
The outdoor condenser coil needs unrestricted airflow to expel heat. Leaves, grass, or dust buildup can drastically reduce its efficiency.
DIY solutions:
- Keep at least 2 ft clear around the unit.
- Gently hose the coils to remove debris.
- For heavy buildup, call T & M to schedule a professional coil clean.
6. Faulty Compressor or Electrical Components
The compressor pressurizes refrigerant, making the cooling cycle possible. If it or electrical components such as capacitors or contactors fail, airflow may continue while cooling stops.
Common signs include:
- Warm air despite fan running
- Strange noises
- Frequent breaker trips
When to call a pro: Replace or repair by T & M’s trained technicians to avoid further system damage.
7. Leaky or Poorly Insulated Ductwork
Cool air can escape through leaks or poor insulation—increasing cooling costs and preventing rooms from reaching the set temperature.
Fixes include:
- Inspecting accessible ducts and sealing gaps with mastic or metal tape
- Insulating ducts in attics or crawl spaces
- Calling T & M for a full ductwork inspection
8. Improperly Sized AC Unit
If your AC is too small, it simply can’t cool effectively; if it’s too large, it cools too quickly and fails to dehumidify, leaving the space clammy. T & M can assess your home’s cooling load and recommend a properly sized system for optimal comfort and efficiency.
Maintenance Tips from T and M Heating & Air Conditioning
Prevent problems before they start by:
- Replacing filters every 1–3 months, or more often with pets
- Clearing debris around the outdoor unit
- Scheduling biannual HVAC tune-ups, spring and fall, to ensure peak performance.
- Considering a smart thermostat to optimize cooling cycles and energy use
T and M Heating & Air Conditioning Your Local AC Repair Company in Bay Minette, AL
If your AC is humming but the air isn’t cool, you’re likely dealing with airflow restrictions, refrigerant issues, dirty components, electrical failures, or sizing/ductwork problems. Start with filter and thermostat checks, clear outdoor debris, then thaw frozen coils. For refrigerant, compressor, or electrical issues, or if problems persist, reach out to T & M Heating & Air Conditioning. Our certified technicians have the diagnostic tools and expertise to quickly restore your comfort and keep your system running efficiently.
Want help now? Contact T & M Heating and Air Conditioning for same‑day service and beat the heat before it beats you.