LG System-3 Losing Gas: Leak Outdoors, Not Inside Walls

Cooling falling away across several rooms on a system with pipework buried behind finished surfaces. The run between the outdoor unit and the indoor units is unusually long. Nothing visible anywhere suggests where the loss is actually happening.

The cheap tests come first, and here that ordering is worth real money. Accessible joints at the outdoor unit can be examined and isolated in an hour, and concealed pipe can be pressure-tested as a section without touching a single wall. Only if the concealed section fails that test does anyone need to consider opening it. Reversing the order means paying for demolition to reach pipe that was never the problem.

A long run means more pipe, and more pipe is assumed to mean more risk. In practice the joints do most of the failing, and the joints are concentrated at the two accessible ends. Buried pipe sits in a stable, dry environment with no vibration and no weather on it, which is a far gentler life than an outdoor connection ever gets. Length raises anxiety more than it raises risk.

The outdoor joints are repaired and the walls are left alone, which is the outcome the testing order made possible. The principle transfers to any concealed service: isolate and test in sections before opening anything, and treat demolition as the last resort rather than the diagnostic method. It is worth asking outright whether a concealed run has been pressure-tested before agreeing to expose it.