I have an 9 year old carrier weathermaker 9200 gas furnace. I'm getting no heat from the downstairs unit. The upstairs unit is working fine. I took the cover off, and I can see the black electric motor(?) spinning, yet nothing is blowing out through the vents. When I look at the bottom right front of the area below the electric motor / blower-type assembly, I see 3 LED's blinking. 3 fairly rapid flashes; followed by 1 long steady flash. It continues to do this over and over.

Look on the inside of the furnace door/cover should be some information that will tell you what the codes are, and give you a start as to where to start looking for prob.

Thanks. I did so. The 31 LED code says " pressure; draft safeguard; auxiliary-limit (when used); or blocked vent shutoff (when used) switch did not close or reopened. I have no idea what that means

Its time to make that dreaded phone call.Call the man,the hvac service tech that does knows what he`s doing.It will be worth it all in the long run.

Oh well. Had to try. Thanks for the help anyway