Your AC Is Running But Not Cooling, Here's Why
You can hear the system running, the fan is blowing and the outdoor unit sounds like it's working, but the air coming from your vents is barely cool or even warm. The thermostat never reaches the set temperature, and the system runs for hours without making a difference.
What You Are Experiencing
You can hear the system running, the fan is blowing and the outdoor unit sounds like it's working, but the air coming from your vents is barely cool or even warm. The thermostat never reaches the set temperature, and the system runs for hours without making a difference. This is one of the most urgent AC problems we see across the Piedmont, especially during the first real heat wave of the year.
Common Causes
Low refrigerant from a leak
Refrigerant is what absorbs heat from your indoor air. When levels drop due to a leak, the system physically cannot transfer enough heat to cool your home. The system runs but produces little cooling.
Dirty or blocked condenser coil
The outdoor unit rejects heat from your home. When the condenser coil is clogged with dirt, pollen, grass clippings, or cottonwood seeds, heat can't escape and the system loses cooling capacity.
Frozen evaporator coil
Low airflow (from a dirty filter or blower problem) or low refrigerant can cause the indoor coil to freeze. A frozen coil blocks airflow entirely, you'll feel weak airflow and no cooling.
Failed compressor capacitor
The capacitor helps start and run the compressor. A weak or failed capacitor means the compressor can't run at full speed or may not run at all, while the fan continues blowing uncooled air.
Thermostat or control issue
A malfunctioning thermostat may be sending the wrong signals. The system may run in fan-only mode or cycle improperly, giving the impression it's cooling when it isn't.
When to Call a Professional
Check your air filter first, if it's clogged, replace it, turn the system off for 2 hours to let any ice melt, then restart. If cool air returns, the filter was the problem. If not, or if you notice ice on the refrigerant lines or outdoor unit, call for professional diagnosis. Continuing to run a system with a refrigerant leak or frozen coil can cause compressor damage, a much more expensive repair.
How We Fix It
We start with a comprehensive diagnostic: checking refrigerant levels, measuring superheat and subcooling, inspecting the evaporator and condenser coils, testing the capacitor and compressor, and verifying thermostat operation. Most of these repairs can be completed in a single visit. For refrigerant leaks, we locate and repair the leak before recharging, simply adding refrigerant without fixing the leak means you'll be calling again in weeks.
Related Services
Frequently Asked Questions
Should I turn off my AC if it's not cooling?
Yes, especially if you see ice on the indoor or outdoor unit. Running a frozen system can damage the compressor. Turn it off, let it thaw for 2 hours, replace the filter, and restart. If it still doesn't cool, call for service.
How much does it cost to fix an AC that's not cooling?
It depends on the cause. A dirty coil cleaning runs $150–$300. Capacitor replacement is $150–$350. Refrigerant leak repair and recharge can range from $400–$1,500. We diagnose the specific problem and quote the repair before starting. Call 336-357-5583.
Can I just add refrigerant myself?
No. Refrigerant handling requires EPA certification, and simply adding refrigerant without fixing the leak is wasteful and illegal. More importantly, the wrong charge level can damage your compressor. Always have a licensed technician handle refrigerant.
Talk to a Technician
Call Davidson Heating & Air at 336-357-5583. Serving homes and businesses since 1984.