Came out to call for a system not cooling properly. Customer stated that they put in a mini split unit and set it up, but it was only blowing warm air. They think they let all the refrigerant out of the line. I checked it and found it to have minimal pressure in the line. Let customer know that I would have to recharge system to specs, but before that I went through and made sure all of the flare fittings were tight. Refastened the flares behind head unit and charged system to correct charge of 1.5lbs. Plugged unit in and cycled it on. Checked operation and showed customer how to use remote. Unit is now cooling.