The answer to 'how to fix installation' is to first identify the specific issue with the HVAC installation. Common problems include improper ductwork, incorrect refrigerant levels, or electrical wiring problems. Start by inspecting the system and looking for any visible signs of damage or improper setup.
If you feel comfortable troubleshooting the issue, you can try making minor adjustments or repairs yourself. However, for more complex problems, it's best to call in a professional HVAC technician. They have the expertise and equipment to properly diagnose and fix installation issues, ensuring your system is running safely and efficiently.