My condo has a Hotpoint dryer. It is about 3 years old and last fall it no longer dried. I took the dryer hose off from the wall and the dryer works fine, heats the condo. The dryer vent goes into the wall, then up after only about 8 inches, then goes up to what I believe is between the floor joists and out the wall. The outside has a venting louver but there is no movement of air with the dryer on. Is there a clog in the venting or is maybe the blower motor or belt has become weakened not to be able to push the air outside?

Hi.

With most Hotpoint/GE dryers the blower motor is not spin by a belt. The problem is unlikely the blower motor. The problem is lint in the air ducts and in the blower housing. The lint results in overheating and the high limit switch cuts off the power to the heater (burner or element depending on the model).
As a result the dryer does not heat up.

Access the heating group and remove lint from the air ducts. Also clean the lint filter.

Hotpoint appliances are built by GE. Below service manuals for different GE-manufactured dryers:

Technical Service Guide

Technical Service Guide

Service manual

ELECTRIC & GAS DRYER SERVICE MANUAL(Kenmore)