The following summer, we had the exact same problem
When we first moved into our house, we knew that the packaged heating and cooling unit would need to be replaced within a few years. The system was obviously quite old. In our local area, air conditioning is the priority. The outdoor temperature frequently climbs into the high nineties and triple digits. The humidity levels are extreme. While the winters are brief and mild, conditions in the mid to low forties required heating. We were fortunate that the heating/cooling unit operated reliably for nearly five years. However, it struggled to handle the demands during winter. It often iced over and we ended up buying several electric baseboard heaters to help out. While the system provided sufficient cooling, the operation was especially loud. A few years ago, during the middle of summer, I noticed that the house suddenly felt overheated and sticky. I realized that warm air was flowing from the vents. I checked that the thermostat was set to cooling and also changed the batteries. I then hired a local HVAC contractor for repair. I fully expected the HVAC technician to recommend the system be replaced. An inspection of the unit revealed a small refrigerant leak. The technician said there was no way to know if the leak was old or new. He suggested refilling and recharging the refrigerant and hoping for the best. The cost of the repair was two hundred dollars. The heating/cooling worked just fine for one year. The following summer, we had the exact same problem. This time, I was unwilling to invest more money into prolonging the life of an outdated piece of equipment. The new system easily handles year round demands, operates more quietly and has significantly reduced our monthly energy bills.