How to Fix a Broken Door Lock

A stiff or broken door lock is a security concern. Most problems are caused by misalignment or wear rather than the lock mechanism itself failing.

Likely causes

• Door misaligned due to settling or humidity
• Worn or dirty lock mechanism
• Broken or bent key inside the lock
• Faulty latch or barrel
• Damaged door frame

Step-by-step fix

1. 1
   Lubricate the lock

   Spray graphite lock lubricant or PTFE spray (not WD-40 — it attracts dust) into the keyhole and on the latch. Work the key in and out several times.

2. 2
   Check door alignment

   If the latch does not line up with the strike plate, the door has moved. Look for a gap at the hinge side or the latch scraping the strike plate.

3. 3
   Adjust the strike plate

   Loosen the strike plate screws and shift it slightly up or down to align with the latch. Plastic shims can help here.

4. 4
   Remove a broken key

   Use needle-nose pliers or a dedicated broken key extractor tool. Do NOT try to push it further in. Locksmiths charge around £60-100 if you cannot extract it yourself.

5. 5
   Replace the euro cylinder

   If the barrel is faulty, the euro cylinder is the replaceable part in most UPVC door locks. Measure the existing cylinder (in mm, from screw hole to each end) and buy a matching replacement. This is a 10-minute job.

6. 6
   Call a locksmith for entry

   If you are locked out, call a locksmith. In the UK, always ask for pricing upfront — reputable locksmiths will give a quote before starting work.

Frequently asked questions

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