The most common reason an AC runs but doesn't blow cold air is low refrigerant caused by a slow leak. Refrigerant isn't consumed like fuel, it circulates in a sealed loop, so if levels are low, there's a leak somewhere, usually at a line-set fitting, the evaporator coil, or the condenser coil. As refrigerant drops, the evaporator coil can't absorb enough heat from the air passing across it, and the air coming out of your vents gets progressively warmer. In advanced cases the coil freezes over and airflow stops entirely, just one of several reasons a central AC stops blowing cold air. In Los Angeles, leaks often appear at the 8 to 12-year mark as vibration and thermal cycling loosen joints. Only an EPA-certified technician can legally recharge refrigerant, and a recharge without leak repair is a waste, it'll leak out again in weeks. Call LA Heating and Air at (818) 660-1062 for same-day leak detection.
