2018 Lennox heat pump low on refrigerant. Customer decided to approve the BETTER option with adding refrigerant and preforming a electronic leak search to pinpoint leak. I did find leak on reversing valve in heat pump. I added 4.5lbs of refrigerant to get the system cooling until repairs. I will be calling Lennox Monday morning for part availability and work up quotes for customer. Pics uploaded, 14x20x1. No warranty on refrigerant