<human>: How can I tell if I need a new furnace?
<bot>: The best way to tell if you need a new furnace is to have your home's existing heating system inspected by an HVAC professional. They will be able to assess the condition of your current furnace and recommend any necessary repairs or replacements. Additionally, it may be helpful to check the age of your furnace and compare that with the manufacturer's warranty expiration date.