Warm Air Blowing from Vents: This is the most obvious sign of a problem. If your AC is running but the air coming out of the vents isn't cool, it could be due to a refrigerant leak, a malfunctioning compressor, or a blocked condenser coil.

Weak or Inconsistent Airflow: If the air from your vents seems weaker than usual or if some rooms are getting less airflow than others, it could indicate a problem with your blower motor, a clogged air filter, or issues with your ductwork.

Unusual Noises: While some operational noise is normal, you should never hear grinding, squealing, clanking, or banging sounds. These noises often signal a serious mechanical issue, such as a failing motor or a loose component that needs immediate attention.

Foul or Musty Odors: A musty smell can be a sign of mold or mildew buildup in your system's drain pan or ductwork. A burning smell might indicate an electrical problem, such as an overheated motor or frayed wiring.

Frequent Cycling (Short-Cycling): If your AC unit is constantly turning on and off in short bursts, it is "short-cycling." This can be caused by a dirty air filter, an oversized system, or a refrigerant leak. Short-cycling puts unnecessary strain on your compressor and can lead to a premature system failure.

High Humidity Indoors: One of the key functions of an AC is to remove moisture from the air. If your home feels sticky or damp despite the system running, it could indicate a problem with the unit's ability to dehumidify.

Water or Refrigerant Leaks: Any moisture or puddles of water around your indoor or outdoor unit are a cause for concern. A frozen evaporator coil can lead to water leaks, while oily spots or a hissing sound can be a sign of a dangerous refrigerant leak.