Mini-split lines must be vacuum-pulled for 30 minutes minimum — most installers rush this

Per EPA Section 608 and all manufacturer installation manuals, the refrigerant lines must be evacuated to 500 microns and held for 30 minutes to verify no leaks. Many DIY and budget installers skip this or only pull for 5 minutes. Residual moisture in the lines causes acid formation that destroys the compressor within 2-3 years. Always verify with a micron gauge, not just a manifold.