Why won't my uPVC door lock when closed?


There could be a few viable causes for a door that won't lock properly. It could be a problem with the locking mechanism, the key, the handle, or it may even be caused by the weather.

Why won't my uPVC door lock when closed? Why won't my uPVC door lock?

My French door won't lock when it's closed

  • Heat. Like other uPVC doors, French doors will expand in hot weather or direct sunlight, which is particularly common in south-facing gardens. Wipe the door with a cloth soaked in cold water. Alternatively, hose down the door's outer frame with water for around a minute.

    Some DIY aficionados may be tempted to level the doors to get them to shut correctly. However, it may be worth holding off on this handy work, as the doors will go back to their original position when the temperature cools down.
  • Cold. Icy conditions can cause uPVC doors to contract and, in extreme conditions, could even freeze the lock. Warm water applied to the outside of doors or lock using a cloth could remedy this.

    Using a hairdryer to warm the edges of the door or lock could also provide a fix. Be sure to set the hairdryer to low heat and hold it around 10-15" (25-35 cm) away from the door.
  • Obstructions. Most modern doors are fitted with a multipoint locking system. Check for debris or an obstruction on the inner frame and bottoms of both doors.

My entrance door won't lock when it's closed

  • High or low temperatures. In the peak cold or warm months, it's common for a uPVC door to expand in heat or contract in severe cold. Repeatedly wiping the door with a cloth soaked in warm or cold water will get it back to its natural state.
  • Blockage. Check for any blockages on the outside of the door, as well as the frame of the doorway. The door may engage a lock at multiple points, so be sure to check all locking points are clear. Also, make sure that nothing is caught on the bottom edge of the door.
  • Lock snib. The snib is a button or switch that holds the locking bolt in or out. If the snib is engaged, release it to be able to lock the door.

My patio door won't lock when it's closed

  • The sliding door has come off its track. The door will need to slide freely into place to be able to lock correctly. If you can't get the door back into its track, you may need to speak to the door's supplier.
  • The locks are being obstructed. Check the side of the door to ensure nothing is trapped or blocking the door's locks.
  • The door has expanded due to heat. Heat, caused by a patio heater, hot weather or direct sunlight, could cause your patio door to expand. Cooling down the door with cold water and a cloth would get the door back to normal.

Other common uPVC door locking problems

My uPVC door won't latch

If the uPVC door won't latch correctly, there may be an issue with the spring mechanism in the door. Open the door and press the latch with your finger.

If the latch springs out, it may be out of alignment or shifted slightly.

If the latch doesn't spring out, the springing mechanism may have failed and would need to be replaced.

A few other reasons this could happen are:

  • Fluctuations in temperature. Wipe a cloth soaked in warm water (in cold conditions) or cold water (in warm conditions) around the door to combat it expanding or contracting.
  • Dropped door. If the door is angled slightly, it would need to be levelled to ensure that it sits flush with the frame.

My key won't insert into my uPVC door

There are several reasons your key won't insert into your door:

  • Are you using the right key? As obvious as this may be, sometimes the simplest solution can fix the problem.
  • Have you recently got a key cut? If a newly-cut key doesn't insert into a door, it may have been poorly cut. Contact the locksmith that you got the key from as most will offer a replacement key free of charge.
  • Is there debris in the lock? You may be able to remove the debris carefully using thin wire, such as fishing line or guitar string.
  • Is the key bent? The locking mechanism will only work when the key is straight, so get a new one cut or use a small blunt object to straighten it out. If the door is from Everest, you can have extra keys cut using Everest Key Cutting Service - call 0844 892 0177.
  • Is the door or key worn, old or cracked? A door's locking mechanism or a key could be faulty due to many years of service. If the key is worn, a locksmith may be able to cut a replacement for you. However, if the lock is the cause, a new door with a modern locking system would drastically improve the security of your home.

Note: We don't recommend using oil, grease or WD-40 for a door lock problem. Use light machine oil or graphite powder as lubrication to care for your door.

My key has broken in my uPVC door

This is generally caused by an old key or locking mechanism or by using too much force. Trying to remove the key yourself could end in more damage. Contact a locksmith to remove the key from the lock.

My uPVC door won't lock when hot

High temperatures and direct sunlight can make a uPVC door expand, so hot weather could throw the door out of alignment slightly. Dowse the door with cool water or pat around the outer sections of the door with a cold, damp cloth. Alternatively, you can wait for the temperature to cool down slightly and the door will go back to its normal state.

Secure uPVC doors near you

Recent crime stats have shown that a shocking 74% of burglars gain entry to a home through the front door. This undoubtedly makes security one of the most important considerations when looking for a new door. Check out our door buying guide to help you find the perfect one for your home. Get a free quote or contact us online.