My dryer is tumbling and heating but not drying

too much lint blocking the vent hose.  start at the lint trap and work your way along removing all the lint you see.  if the trap is clean, remove the hose from the vent and and dig out the lint from there.  at some point you have an obstruction to your air flow and your clothes will never dry unless you can exhaust the wet air

We are having the same problem right now.  What we had to do was go up in the attic, find the pipe that leads to the dryer and clean it out because there was tons of lint piled up in there.  It won't let the moisture go out of the dryer if it is build up like that.

You really need to clean that out because it can also cause a fire in you home!