The answer to 'system upgrade not cooling' is that there could be several common causes, such as improper installation, incorrect sizing, or a problem with the new system components. Symptoms may include warm air coming from the vents, high energy bills, and inconsistent cooling throughout the home.
In many cases, the solution will require the expertise of a professional HVAC technician. They can diagnose the issue, make necessary adjustments or repairs, and ensure the new system is properly installed and functioning as intended. Attempting to troubleshoot or repair a cooling system upgrade on your own can be risky and may void the warranty, so it's generally best to call in a qualified professional.