What is a key indicator of a faulty capacitor in an HVAC system?

Swelling or bulging of the capacitor's casing is a significant indicator of a faulty capacitor in an HVAC system. Capacitors are designed to handle a certain amount of voltage and current, but if they are subjected to excessive stress or age, the internal components can fail. When this happens, the electrolyte inside the capacitor can expand, causing the casing to bulge or swell. This physical deformation is a clear sign that the capacitor is no longer functioning properly and may lead to complete failure if not addressed.

Other indicators of potential issues may include noise during operation, inconsistent airflow, or frequent cycling of the unit, but these symptoms can be associated with various other HVAC components as well. They do not specifically pinpoint capacitor failure. Swelling or bulging is unique to capacitors and serves as a direct visual cue to technicians for diagnosis and replacement before more serious system failure occurs.