I have a 2003 Lennox gas fired, forced air furnace. The gas fires up but the blower only works sometimes. The HVAC company says I need a new furnace, or new motherboard and air pressure switch. My son did the diagnostic test from the manual and can’t see that I need anything more than new relay. What is your opinion, please?


I don't know what a 2003 Lennox design is but if the testing shows a fan relay is bad then I would definitely try it before making a larger purchase since they aren't that expensive.

Updated on January 8, 2018

Original Article:

Troubleshooting Common Furnace Problems With an HVAC Expert
By Dan Robbins