Symptoms and causes are different
A water stain may be caused by a roof leak, a plumbing leak, condensation, or an old repair that is already dry. A sticking door may be a hinge problem, but it can also point to movement in the frame or surrounding structure.
Treating the symptom without checking the cause can make a repair look complete while the underlying problem continues.
Why this matters to property managers
Repeat service calls cost more than the repair itself. They also create tenant frustration, scheduling time, and extra administrative work.
A handyman should be willing to explain what he sees, what he believes is causing it, and whether the requested repair is likely to solve the problem.
The better question
Instead of asking only “What needs to be replaced?” ask “What caused this to fail?” That one question often changes the entire repair.