Trane air conditioner runs but does not cool well; supply air is only slightly cooler than room temperature.

Safety first: Turn off power before cleaning coils or filters. Do not attempt to adjust refrigerant charge yourself.

• Replace filter: Install a new air filter of the correct size and rating.
• Clean indoor coil: If accessible, gently brush dust from the evaporator coil and use a no-rinse coil cleaner. Ensure condensate drain is clear.
• Clean outdoor coil: Remove debris and wash the Trane condenser coil from inside out with low-pressure water.
• Check temperature drop: With system running 15–20 minutes, measure temperature at a return grille and nearest supply vent. A typical drop is 15–20°F. Significantly less may indicate low charge or other issues requiring a technician.

If performance remains poor after cleaning and airflow corrections, schedule a Trane technician to check refrigerant charge and system capacity.