LG Unit Topped up Twice: Corroded Outdoor Pipe Connections

Cooling that fades over a few months, is restored by having gas added, and fades again on a similar timescale. Each cycle is a little shorter than the last. The system is otherwise unremarkable and reasonably maintained.

The repeat is the diagnosis. A sealed system that needs refrigerant twice has an opening somewhere, and the interval between top-ups is a rough measure of how large it is. That reframes the visit entirely: the useful work is finding where the loop is open, not restoring the pressure inside it. Outdoor connections are the first place to look, because they are exposed to weather, they carry joints, and they can be reached without opening anything.

Joints at the outdoor unit sit in the weather and carry the vibration of a running compressor. Both work against a seal over the years. Once a joint begins to pass refrigerant, the loss is slow at first and accelerates as the gap opens, which is why the intervals between top-ups keep shortening. Nothing about the system is consuming refrigerant, and nothing about it ever was.

The failed joints are made good and the system is charged properly afterwards, which is a repair rather than a postponement. The economics are worth putting plainly, because this is where households lose most. Repeated top-ups cost more across a couple of years than the repair does, and every one of them releases refrigerant into the atmosphere for no lasting benefit.