the latch, handle, hinge or ordinary running hardware no longer lines up or operates normally. Replace accessible compatible roller assemblies on an accepted panel, set the height and check ordinary travel and stops.
Signs: the door sags, rubs, sticks or has uneven gaps around the opening or the door closes poorly despite an otherwise sound visible opening. Causes: normal wear in hinges, latches or compatible mechanical hardware or local damage to an accessible component rather than an assumed structural defect.
A panel can have more than one roller assembly, and the condition of each matters. Discuss whether compatible assemblies need replacing together. Replacing only an obvious damaged wheel may leave an uneven panel if the other support is worn or cannot be adjusted correctly.
After fitting, the panel height needs checking against the opening and compatible hardware. Excessive adjustment is not a cure for an unsuitable part. The aim is supported travel and workable clearances, with any remaining frame or track limitation explained before handover.
Keep the running surface clear and follow the hardware instructions. Report renewed drag rather than repeatedly forcing the panel. Limits: Ordinary non-powered safely handled panels only. No heavy specialist lifting, glazing work, powered operators, structural changes or access-control integration.