If your front door can be opened from the outside without using a key, it’s a major security flaw that requires immediate attention. This door lock problem often arises after new door installations, lock replacements, or worn mechanisms, and it can leave your home vulnerable if not corrected.
Possible Causes
Split Spindle Missing or Fitted Incorrectly:
In many uPVC and composite doors, the split spindle separates inside and outside handle operation. If it’s missing or fitted incorrectly, both handles may retract the latch, allowing anyone to open the door freely.
Latch Not Engaging Fully:
If the latch doesn’t line up with the strike plate, the door may look closed, but is only resting against the frame instead of actually securing shut.
Handle or Gearbox Fault:
A worn gearbox or incorrectly assembled handle mechanism can turn freely from both sides, disengaging the latch without using the key.
Incorrect Door Type or Mis-specified Hardware:
Occasionally, installers fit an internal-style handle set to an external door, which doesn’t restrict outside access. This is a common oversight after glazing or frame replacements.
How to Diagnose the Problem
Test with Door Open:
Lift and lower the handle to feel for latch movement—if it retracts from both sides, the spindle or gearbox is at fault.
Check Exterior Handle:
Exterior handles should not operate the latch when the lock is engaged.
Inspect Split Spindle Slot:
Remove the handle and inspect for a broken, missing, or single-piece spindle across both sides.
DIY Fixes and Quick Solutions
- Adjust or replace the split spindle to ensure the outdoor handle no longer controls the latch.
- Replace any incorrect handle sets with ones designed for external use.
- Refit or adjust the multi‑point lock gearbox if the mechanism feels loose or inconsistent.
- Confirm the latch keeps on the door frame secure and aligned; tighten screws if loose.
Locksmith Tip
If your door handle operates the latch from both sides, even when “locked,” call a locksmith immediately. They can reinstall the split spindle correctly, verify gearbox alignment, or fit a new multi‑point lock, restoring proper function and your home’s first line of defence.
