Why Your AC Isn't Cooling (and What to Check First)

When the air conditioner is running but the house just will not cool down, it is frustrating — and not always a sign of a major failure. A few of the causes are things you can check yourself in a couple of minutes.

Check these first

• The thermostat. Make sure it is set to cool, the target temperature is actually below room temperature, and the batteries are not dead.
• The air filter. A clogged filter chokes airflow and is one of the most common reasons a system underperforms. Replace it and see if things improve.
• The outdoor unit. The condenser needs airflow. Clear away leaves, grass clippings, and anything crowding it, and gently rinse the fins if they are caked with dirt.
• The vents and registers. Confirm they are open and not blocked by furniture or rugs.

Signs the problem needs a pro

If the basics check out and the house still will not cool, the likely culprits are beyond a DIY fix: low refrigerant from a leak, a failing compressor, a frozen evaporator coil, a bad capacitor, or a fan motor that has quit. Ice on the refrigerant lines, warm air from the vents, or the outdoor fan not spinning all point to a repair call.

Leave the refrigerant alone

Refrigerant is not a DIY item. It is handled under pressure, requires EPA certification to purchase and charge, and a low charge almost always means there is a leak that needs to be found and sealed — simply adding more is a temporary and often illegal patch. This is where a licensed HVAC technician earns their keep. Homeowners around Dallas can reach out to the crew we recommend for air conditioning repair in the Dallas area, who can diagnose a weak-cooling system properly.

A little prevention

Changing the filter on schedule and keeping the outdoor unit clear prevents a surprising share of cooling problems before they start.