The vent blower doesn't start each time the heat unit comes on. It hums if you hold down the cabinet safety switch and help the vent start by pushes the fins with a screw driver it starts and works for several days. But its down again so I'm calling a tech what is your oppinon on the problem? To bad they don't build furnaces like Michelin tires I'd never have a problem.

Sounds like the vent blower motor as you call it might be defective.