Condition
AC Not Cooling House but Unit Running
Outdoor unit and indoor blower operate, but home does not cool. Points to refrigerant charge or heat exchange.
Possible Causes
Low Refrigerant Levels
A leak in the refrigerant lines prevents the system from absorbing heat efficiently.
Root Cause Analysis →Diagnostic Tests
- Check subcooling/superheat
- Leak test with nitrogen
- Pressure test
Repair Options
Dirty Evaporator Coils
Dust buildup on the coils restricts airflow and stops heat absorption.
Root Cause Analysis →Diagnostic Tests
- Inspect coil surface
- Measure temperature delta
- Check airflow
Repair Options
Welded AC Contactor
Electrical arcing can 'weld' the contactor shut, causing the outdoor unit to run constantly.
Root Cause Analysis →Diagnostic Tests
- Visual inspection
- Ohm test across contacts
- Check for pitting
Repair Options