Low risk
A door that catches on the floor or the frame has usually dropped on its hinges. Check the guarantee, then check how the door sits in the frame before anyone turns a screw.
Most stiff sliding doors need the track cleaned before anything is adjusted. Grit in the bottom track wears the rollers and pulls the lock out of line.
A uPVC door is designed to let water into the frame and drain it out. If the drainage holes are blocked, the door looks as if it is leaking. Test them first.
A bifold that rubs, jams or will not lock usually needs a clean track and small adjustments to the panel height and keeps, not a new door.
Water inside a uPVC frame is normal and drains out. If the drainage holes are blocked it looks like a leak. Check that, and whether it is condensation, before blaming the frame.
Wind noise means air and sound are getting through a gap: a worn seal, a trickle vent, a loose sash or a poor fit. Find where the noise is coming from first.
Describe the job and get a fixed price from a local window fitter.
