Also known asplumb lineplumb bobsoot sahulsut and sahulसाहुलसूत साहुलसावल
A main door that leans inward or outward even by half a degree to two degrees stops giving results; check it with a plumb line (soot-saval) and a water level.
Plumb bob on a thread (soot-saval)
Main door and its frame
A main door on an auspicious pad still fails when the route to the gate is wrong, when there is any vedh in front, when the house faces a cremation ground, or when the door is out of plumb.
Plumb line (sahul)
Main door and the area in front of it
When the route to the boundary gate is heen bahu (anti-clockwise) or prishth bhang (circling the house), when there is any dwar vedh in front such as a T-point, shool vedh, pole, tree, pit or garbage, when the house faces a cremation ground, or when the door is out of plumb and leans inward or outward. In any of these cases even doors on N3, N4, E3, E4, S4 or W4 do not give their results.
First check whether the door is in plumb and level with a plumb line and water level, and whether a wall or another door stands in front of it. In this case the entrance was fine; the real cause was a full basement in the South and West portion, together with a problem in the North-East.
They are the mason tools for checking that a wall or door is true: a plumb bob hanging on a thread like a pendulum shows whether it is in one line from top to bottom. Masons also use a guniya (L-shaped square) and a water level, and a vastu consultant should carry the plumb line and water level.