My current AC system (Carrier 15 years old) is about to give up on me. Yesterday it worked all day non-stop, but could not bring the temperature below 76°. I checked temperature at the return and register and got 60° at the register and 73° at the return. Outside temp was 96°, I live in Doylestown PA area. My outside unit was disconnected 2 years ago (during patio construction) and reinstalled within 2 days. Freon was added at the same time. Should I bother hiring someone to find a problem or just get a new system? The house is a 1700 sq. ft. Also, if there are any installers on this forum, who do work in Bucks county area, please send me a message.