AC Unit Not Cooling: Filters, Coils & Refrigerant

Warm air from a running AC usually starts with a dirty filter or coil — and sometimes low refrigerant.

By Marcus ElleryOctober 3, 20253 min read read

Written by Wade Holbrook, Lead Technician — True Fix Dallas. Factory-trained, EPA-certified, 9 years servicing Dallas–Fort Worth.

In the Texas heat, an AC that runs without cooling is urgent. Work from the cheapest, easiest cause up.

Replace the Air Filter

A clogged filter chokes airflow and can ice the coil.

Fix: Swap or wash the filter monthly during cooling season.

Dirty evaporator or condenser coils cannot transfer heat.

Fix: Clear debris from the outdoor unit and have the coils cleaned annually.

A unit low on refrigerant cools weakly and may hiss or ice up.

Fix: Refrigerant work is regulated — a licensed technician must locate the leak and recharge.

Not sure what's wrong? Book online — every visit includes a free diagnosis.

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