If your bath or shower handles become loose, tightening them is a simple process that restores their functionality.
Start by closing your tub stopper or placing a rag over the shower drain to prevent anything from falling down. Next, use a utility knife or flathead screwdriver to remove the small cap (about 5mm across) on the underside of the handle and set it aside. Insert the appropriate-sized Allen key into the hole, securing it into the set screw, and rotate clockwise to tighten until snug. After tightening, remove the Allen key and check the handle for stability by giving it a gentle jiggle—it should now be secure. Finally, place the set screw cover back into the hole on the underside of the tap and press it into place.
For smooth operation and security, regularly check your bath and shower handles for any loosening.