Overview
This exact symptom - handle lifts fully but the key refuses to turn afterwards - nearly always means the cylinder cam isn't engaging the gearbox pawl. It's a 30-minute fix if caught early.
Symptoms
- Handle lifts smoothly and hooks extend.
- Key turns freely but nothing locks.
- OR key won't turn at all after the handle is up.
Common causes
- Cylinder cam sheared or worn.
- Gearbox pawl has failed to reset.
- Cylinder wrong length - cam not reaching the gearbox.
- Screw holding the cylinder loose or missing.
When to call a professional
- Cylinder screw is missing.
- Reseating hasn't fixed it.
Prevention
- Lubricate the cylinder twice a year with a graphite or PTFE lock spray - never WD-40 or oil.
- Grease the hooks and rollers on the door edge every 6 months.
- Always lift the handle to engage the multi-point locks before turning the key - this takes load off the gearbox.
- Never force a stiff key - book a service call before the mechanism snaps.