A musty smell from your furnace can indicate several underlying issues, such as mold growth in the ductwork or a buildup of dust and debris. It's essential to consider factors like the age of your system, the last time it was serviced, and the overall air quality in your home. Regular maintenance can help prevent these odors and ensure your furnace operates efficiently. If you're experiencing this issue, it might be time to investigate further. Ask Improvi.ai for personalized guidance on how to address this concern and improve your indoor air quality.