I have dual fuel (air to air heat pump with propane backup) and can hear the furnace fan running as normal. The furnace and heat pump are about 16 years old and have never caused a problem until now. Problem is there is virtually no air coming from any of the vents. Flter was just replaced (it was quite dirty) and the main blower is running. I can see no breaks in the vent system. Is there anything else I should check before calling in a professional?

Thank you for your time.

Is it a direct drive or belt drive? I have seen belt drive units with a thrown belt and direct drive units shear off the fan coupling. Open the air handler front, depress the safety switch and have someone switch the T'stat fan to ON. What happens?

Is it a direct drive or belt drive? I have seen belt drive units with a thrown belt and direct drive units shear off the fan coupling. Open the air handler front, depress the safety switch and have someone switch the T'stat fan to ON. What happens?

Thanks for your attention to this problem. I figured out it was a frozen A/C coil in the furnace thus hindering the airflow.
Thanks again for your thought!

Probably low on Freon or fins are obstructed with debris.