You Carrier ac units probably had faulty installation. I doubt it be manufacture problem. I?m guessing all 5 Carrier central air conditioner units are installed by one company. What wrong with it? What does the contractor or the technician said?
A lot contractor considers Carrier as one of the top line units. It has problem within five years old. That really surprises me. By the way, your Carrier ac units should be within the warranty period.
