When your air conditioner runs but doesn’t cool, it’s one of the most frustrating problems a Rochester homeowner can face — especially when summer humidity hits. Here are the most common culprits.

1. Dirty Air Filter

A clogged filter starves your AC of airflow, causing the evaporator coil to freeze and drastically reducing cooling. Check and replace filters every 1–3 months.

2. Low Refrigerant

Refrigerant doesn’t get used up — so if it’s low, you have a leak. Signs include warm air from vents, ice on the refrigerant lines, and hissing sounds. This requires a licensed technician.

3. Dirty Condenser Coils

The outdoor unit releases heat through condenser coils. Grass, cottonwood fluff, and debris block airflow. An annual cleaning as part of preventive maintenance solves this.

4. Failed Capacitor

The capacitor starts the compressor and fan motors. When it fails, you’ll often hear a clicking or humming from the outdoor unit but the compressor won’t run. This is one of the most common AC repairs in Rochester.

5. Oversized or Undersized Unit

An AC that’s too large short-cycles, never running long enough to dehumidify. Too small, and it runs constantly without reaching setpoint.

Flower City HVAC serves Rochester and all of Monroe County. Call (585) 577-5944 for same-day AC diagnosis.

Learn more about our AC replacement, or visit our HVAC service in Brighton page.