Arrived on site to perform diagnostic on 1 year old or less mini split. Homeowner had system installed by another company and has not been cooling for a couple days. Has been trying to get a hold of the company that installed it but has not heard back from them. Unit is not cooling and inside head unit is showing an F0 error code, which is associated with refrigerant. Hooked up gauges to unit and found system low on refrigerant which is causing outdoor unit to go into lockout mode. Went over findings and recommendations with homeowner as far as Adding refrigerant and locating a possible leak. While on site, the company that installed it finally gave the homeowner a call back and they said they will be sending someone out on Friday to see what’s going on with the unit. Homeowner wants to hold off on any repairs with us for now until the company comes out to see if they take care of it. System is not operational upon completion.