When Do You Need to Replace Your Locks?
Your Locks Are Working - But Are They Working Well Enough?
Most people do not think about their door locks until something goes wrong. But locks, like any mechanical device, wear out over time - and an ageing or compromised lock may appear functional while offering far less protection than you realise.
Knowing when to replace your locks is an important part of maintaining a secure home. Here are the clearest indicators that it is time to act.
Situations That Require Lock Replacement
Lost or Stolen Keys
The moment you believe your keys are lost rather than temporarily misplaced, you should consider changing your locks. Once a key leaves your possession, you cannot know who might find it, copy it, or use it. This is especially urgent if your address is associated with the keys in any way (a key fob with a home address label, for example).
Options: Full lock replacement is the most thorough option. Rekeying - where the internal pins of the lock are reconfigured to work with a new key - is a faster and cheaper alternative if the lock itself is in good condition.
Moving Into a New Property
When you receive the keys to a new home, you have no way of knowing how many copies of those keys exist. Previous owners may have given copies to neighbours, cleaners, or tradespeople over the years. Changing the locks when you move in is one of the most effective and affordable security steps you can take.
After a Break-In or Attempted Break-In
Even if a break-in attempt was unsuccessful, the attempt may have weakened or damaged your lock. Forced entry attempts - particularly anti-snap attacks on Euro cylinders and kick-in attacks on deadbolts - can leave internal components compromised in ways that are not visible from the outside.
After any security incident, have the affected locks replaced and the door frame inspected for damage.
Outdated Lock Technology
Lock standards have advanced significantly in recent years. If your locks are more than 10 years old, they may lack modern protections such as:
- Anti-snap protection - essential for Euro cylinder locks, which are vulnerable to the snap-and-pull attack technique
- Anti-pick and anti-drill pins - resist common manipulation techniques used by burglars
- Anti-bump resistance - prevents the “bump key” technique that can open older pin tumbler locks in seconds
Upgrading to a BS 3621-rated or Sold Secure-certified lock is a straightforward way to significantly improve your home’s security.
Warning Signs Your Lock Needs Replacing
Watch out for these indicators that your lock is failing:
| Sign | Likely Cause | Action |
|---|---|---|
| Key difficult to turn | Worn pins or cylinder | Replace cylinder |
| Key needs jiggling | Worn key or misaligned door | Replace key first, then lock if still stiff |
| Key gets stuck | Debris in keyway or worn mechanism | Clean first; replace if persistent |
| Lock feels loose or wobbly | Worn mounting screws or cylinder | Tighten screws; replace if loose cylinder |
| Visible rust or corrosion | Weathering or moisture damage | Replace immediately |
| Lock makes grinding noise | Internal wear | Replace cylinder or lock body |
Rekeying vs Replacing: Which Is Right for You?
Rekeying changes the internal pin configuration so that old keys no longer work and new keys are issued. It is appropriate when:
- The lock is in good mechanical condition
- You simply need to invalidate existing keys (after a move, for example)
- Cost is a primary consideration
Full replacement is appropriate when:
- The lock is worn, corroded, or damaged
- You want to upgrade to a higher security rating
- The lock type does not meet current standards (e.g. an old Euro cylinder without anti-snap protection)
- You are upgrading to a smart lock or electronic system
Best Practices When Replacing Locks
Choose Certified Locks
Look for locks bearing the British Standard Kitemark (BS 3621), Secured by Design certification, or Sold Secure approval. These certifications confirm the lock has been independently tested to resist common attack methods.
For uPVC or composite doors with Euro cylinders, specifically choose a cylinder rated to TS007 3-star standard for the highest available protection against snapping.
Do Not Forget the Door Frame
A quality lock in a weak frame provides little real security. When replacing locks, have the strike plate and frame reinforcement checked at the same time. Strike plates should be secured with screws at least 75mm long, driven into the structural timber behind the door casing.
Consider Window Locks Too
When carrying out a security review, do not overlook windows. Ground-floor and easily accessible upper-floor windows are common entry points for burglars and often have inadequate locking.
Use a Professional Locksmith
Incorrect lock fitting - particularly a misaligned strike plate or a cylinder not flush with the door face - significantly reduces a lock’s effectiveness. A professional lock change ensures the hardware is installed correctly and working to its full capability.
Ready to Upgrade Your Locks?
City Locksmith London supplies and installs a full range of high-security locks for homes and businesses across London. We can advise on the best option for your door type and security requirements.
View our locksmith services or get in touch for a free quotation.