Do refrigerant leak sealers work?

Commercial chemical refrigerant leak sealers—sold as aerosol additives designed to circulate inside closed AC loops—can successfully seal tiny, microscopic pinhole leaks in metal tubing or rubber O-rings, but they are not a guaranteed cure-all for major ruptures. These sealants are formulated to react chemically with moisture and air at the exact point of an escaping pressure drop, forming a hardened plug over the crack. However, they are generally intended as a temporary band-aid or a last resort for aging systems, and many professional HVAC technicians discourage their use because sealants can inadvertently clog internal service valves, capillary tubes, and expensive recovery machinery. You can troubleshoot by assessing leak size. You can verify proper repair when professional welding or component replacement permanently restores sealed system integrity without risking equipment clogs.