Refrigerant Leaks at Spring Startup: Identifying and Preventing Common Issues

Spring is when many air conditioning problems show up as refrigerant leaks, often found during a routine tune-up. These leaks don't usually cause the system to stop working right away, so a homeowner may not notice anything until performance gradually declines or internal parts get damaged.

In older systems, five to ten years old, the most common leak spot is the indoor evaporator coil, the part that cools the air inside your air handler. It corrodes over time from a reaction between moisture and airborne chemicals released by building materials like flooring, carpet, and paint. Newer homes are built tighter to save energy, which means these chemicals can't easily vent outside. Instead they get pulled into the HVAC system and speed up corrosion on the coil, eventually creating tiny pinhole leaks.

If a leak turns up in a newer system, the more likely cause is how it was installed, particularly the soldering (called brazing) of the copper refrigerant lines. Skipping steps like flowing nitrogen gas through the lines during brazing, not cleaning the copper thoroughly, or not heating it properly can leave weak joints that fail months or years later. One expert noted that a thorough pressure test with nitrogen gas right after installation catches most of these problems before they become a lasting issue. If your system is in that five-to-ten-year range, or was recently installed, a leak found early is far easier to deal with than one left to damage the equipment.