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uPVC door won't lock or open
Updated October 2026
Most uPVC and composite doors use a multi-point locking mechanism: lifting the handle pushes hooks or rollers into the frame, and turning the key locks them in place. Most faults come from the door dropping or the mechanism wearing out.
Common causes
- Door dropped or out of line: the handle gets stiff to lift. Hinges can often be adjusted.
- Worn gearbox: the handle feels loose or floppy, or won't lift at all.
- Faulty cylinder: the key turns but nothing happens, or the key won't turn.
- Seasonal movement: doors can stick in hot weather as the frame expands.
What you can safely try
Put a little silicone or PTFE spray lubricant on the moving parts along the edge of the door (not oil in the keyhole). Check if the door lifts easily when closed. If the handle is floppy or the door is stuck locked, stop forcing it: that can break the mechanism.
Repair or replace
A locksmith can usually replace just the gearbox, not the whole strip, if the model is still available. While they're there, ask about an anti-snap cylinder (see our guide on upgrading).
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