Troubleshooting

Why Is My AC Running but Not Cooling? 6 Common Causes

2026-02-01·5 min read·By David Moreno

1. Low Refrigerant

If your system is low on refrigerant, it physically cannot cool your home. This usually means there's a leak somewhere — just adding refrigerant is a temporary fix. David finds and fixes the leak first.

2. Dirty Condenser Coils

The outdoor unit's coils dissipate heat. When they're covered in dirt, grass, or debris, the system can't release heat efficiently. A cleaning often restores 10-20% of lost cooling capacity.

3. Failed Capacitor

The capacitor starts the compressor motor. When it fails, the compressor tries to start, can't, and the system runs without actually cooling. This is one of the most common AC repairs David handles — and one of the quickest.

4. Frozen Evaporator Coil

Low airflow (from a dirty filter or failing blower motor) causes the indoor coil to freeze. The system runs but can't absorb heat from your air. If you see ice, turn the system off and call D&D.

What to Do Right Now

Check your filter first — if it's clogged, replace it and wait 2 hours. If the problem persists, check the outdoor unit for debris. Beyond that, you need a professional diagnosis. David's team handles most AC emergencies same-day.

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D&D HVAC Solutions · DC Metro · Northern Virginia · Maryland