AC Not Cooling: Common Causes and What to Check

A practical guide to why an AC may run without cooling well, including thermostat settings, airflow, dirty coils, refrigerant-side issues, and equipment faults.

If the AC is running but the house is not cooling, start with the simplest causes before assuming a major failure.

Start with these checks

• Set the thermostat to COOL and below room temperature
• Check whether the filter is heavily restricted
• Make sure supply vents and return grilles are open and unobstructed
• Check whether the outdoor unit is running
• Look for visible ice on refrigerant lines or the indoor unit

When it points to a service issue

If airflow is normal but supply air remains warm, or if the outdoor unit is not operating, the system may have an electrical, refrigerant-side, compressor, fan, or control problem. Avoid repeated breaker resets.

Next: AC repair in Riverview or AC blowing warm air.

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