Lock stuck – causes and quick help

The most common causes at a glance

A lock almost never jams without a history. These four causes are behind the vast majority of cases:

• Dirty or dry cylinder: dust, abrasion and missing lubrication make the small pins inside jam – the single most common cause.
• Warped door: in heat, cold or damp the door leaf moves. The bolt then no longer meets the strike plate cleanly and jams.
• Worn key: a key worn down over years or copied several times no longer has the exact profile and doesn't engage the pins cleanly.
• Defective cylinder: mechanical wear, a broken spring or a foreign object inside.

What you can safely try yourself

Before calling the professional, you may try two things yourself. First: apply suitable lock spray on a graphite or Teflon base into the cylinder. This loosens dust and lubricates the pins. Do not use WD-40 or oil – these gum up over time and make the problem worse in the long run.

Second: check whether the door is warped. If the key turns more easily when you lift or push the door slightly at the same time, the cause is the door leaf or the hinges, not the lock. What you must never do: turn with force. A jammed key under pressure breaks off – and a small problem becomes a bigger one.

When you should call us

At the latest when the key won't turn at all or spins freely without moving the bolt, you should stop experimenting. The cylinder is then usually defective. We open the door damage-free, check the cause and, if needed, replace the cylinder with a secure model. Often this is cheaper than you think – and you immediately have a working, secure lock again.

How to prevent it next time

A lock appreciates regular care: graphite spray once or twice a year is enough to keep the cylinder smooth. Replace heavily worn keys in good time with a clean cut from the original. And if a door warps seasonally, the hinges can be readjusted – this stops the bolt jamming permanently and the cylinder suffering.