There should be a switch on the furnace itself. Could you have possibly flipped it off accidently? You may have also inadvertently blown a fuse in the unit.
__________________
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!
Not sure about yours. We had the same issue. Found the heater plenum door was not closed and locked. For our unit had to take the forward compartment apart to get to the heater ducts. Door was hanging open. Closed it up and wired its shut. OK now.
Hope its that simple of a solution for you as well.
Good luck
A screw had fallen out of an end plate. I got that fixed. Now it quit running. Fan will not start up. Have tried different ways to reboot the circuit. Still no go. I have not seen any loose wires or connections.