The answer to 'replacement not cooling' is that there are several common causes for a new air conditioning system not providing adequate cooling, including improper installation, refrigerant leaks, and issues with the compressor or other components. Symptoms may include the system running constantly without cooling the home, warm air blowing from the vents, or the system freezing up.
In many cases, the solution may be as simple as adjusting the thermostat settings or cleaning the air filters. However, more complex issues like refrigerant leaks or compressor failures often require the expertise of a professional HVAC technician to properly diagnose and repair. It's generally best to call in an expert if the system is not cooling effectively, as attempting DIY repairs on an HVAC system can be dangerous and may void the warranty.