The answer to 'when to replace system upgrade' is that you should consider replacing or upgrading your HVAC system when it is 10-15 years old, or when it is no longer efficiently heating and cooling your home. As HVAC systems age, they become less efficient, require more frequent repairs, and use more energy, which can increase your utility bills. Upgrading to a newer, more energy-efficient system can save you money in the long run and provide better comfort for your home.
When deciding whether to replace or upgrade your HVAC system, it's important to consider the age, efficiency, and performance of your current system. You should also factor in the cost of repairs, your energy bills, and the potential savings from a new system. A professional HVAC technician can help you evaluate your options and determine the best course of action for your home.