How to rectify a heavy door?
Working carpenter; I live with this on a regular basis.
You need long (3&quot;) screws in the top hinge. One is adequate, two would be better. That's it. Try to use the holes further away from the hinge barrel.
The underlying reason for this is that the people that hung your door left the short screws in place. (Prehung doors are shipped like this because people would be mad if the hinges didn't have all their screws.)
Oh, and pound the hinge pin down properly on the top hinge. That isn't the root of your problem, but it doesn't help.