Homeowner had us out today because the system isn’t cooling properly. Upon arrival we noticed that the system is off and the homeowner told us that he’s been hearing a weird buzzing noise from the outdoor unit. We recently installed a new thermostat and contactor 2 months ago. We noticed lots of ants on the contacts prevent the contactor from fully closing. We also tested 30/5 capacitor and it was out of range reading 20mfd. Homeowner approved to have capacitor replaced and we replaced contactor under warranty. We checked refrigerant pressures which were slightly low and the system uses R22 refrigerant. Informed homeowner and recommend to look at replacing system before refrigerant completely leaks out