alt Hacker Newshttps://www.covenantairesolutions.com/post/what-is-a-furnace...
“At its core, it's a small motor with a fan attached that has one primary job: to vent harmful exhaust gases out of your home before the burners ever kick on. This is the very first step in the heating sequence, and it's non-negotiable for a safe startup.“
The original comment was unclear whether the fan kept spinning while the furnace was running, or if all it did was bypass the safety and the fan didn't continue to spin while the furnace ran. They clarified in their response it kept spinning.