The answer to 'how to maintain system upgrade' is to follow a regular maintenance schedule and address any issues promptly. This includes cleaning or replacing air filters, checking and tightening electrical connections, and inspecting the system for signs of wear or damage. Regular maintenance can help extend the life of your HVAC system and ensure it operates efficiently.
It's important to follow the manufacturer's recommendations for maintenance and upgrades, as well as any local codes or regulations. If you're not comfortable performing the maintenance yourself, it's best to hire a professional HVAC technician to handle it.