Airflow and filter
Check filter fit and condition, accessible blower components, returns, supplies and signs of duct restriction.
Drainage
Inspect the condensate path, drain protection and evidence of prior overflow or biological buildup.
Electrical and controls
Evaluate accessible connections, components, thermostat response and equipment startup.
Cooling performance
Temperature and operating measurements provide context for system performance and any repair recommendation.
When to request professional service
Request service when basic settings and an accessible filter do not explain the problem, or when the system is frozen, leaking, electrically unstable, unusually noisy or unable to maintain a safe indoor temperature.
Shut the system down for smoke, a persistent burning smell, repeated breaker trips, spreading water or severe mechanical noise. Call emergency services for fire, medical danger or another immediate threat to life or property.