🚀 go-pugleaf

If it's a capacitor-run motor, you can simply feed the other side of the
capacitor and the motor will run the other direction.

If it's a series-field motor, you can reverse the leads to either the
field or the rotor and it will run the other way.

Most of the household motors I've seen are one of these two types.  The
capacitor-run motors seem to be rarer nowadays.

If you can get to the motor itself (unplug the furnace first, eh?) you might
well find a little sticker on the motor or under a cover that describes
how to set the motor direction.  It's hard to describe without
handwaving and pictures.
	- Brian