Why Does My Key Turn But The Lock Won't Open?

 

When your key rotates smoothly but the bolt on the door fails to move, the problem lies in the lock's core transmission—the cam. This is a common service call, and it means the vital connection between the key and the locking mechanism has failed.

Here are the most common reasons this happens and what we look for:

• Internal Component Failure: Over years of use, the tiny, intricate pieces inside the cylinder that are meant to link the key's rotation to the cam can snap or wear out. This causes the cylinder plug to spin freely without engaging the rest of the lock, leaving you locked out.
• Worn Clutch Mechanism (Double-Cylinder Locks): In locks that require a key from both sides, a clutch is used to connect the key turn to the cam. If this clutch component is damaged or worn, the key will turn, but the clutch won't pass the rotational power to the cam, resulting in a lock failure.
• Cylinder Plug Disconnect: The rotating part of the cylinder (the plug) has slipped out of its correct alignment with the cam. This means the key is working, but the physical link to the latch is lost, leaving the bolt stuck.
• Key Condition Issues: Occasionally, the problem isn't the lock but a faulty key. A key that is heavily worn, slightly bent, or poorly cut might be just good enough to turn the pins and rotate the cylinder, but not quite correct enough to fully engage the cam to lock or unlock the door.