Home Improvement

uPVC Door Won’t Lock When Closed – What To Do

A uPVC door is always a good solution for your home. Not only will it give your property a more modern look, especially if you decide to combine it with matching windows, but you will also get to experience a long list of benefits like an unlimited range of designs, noise isolation, security, etc. 

But like all things, uPVC doors can develop problems over time and have weak spots. In this article, we are going to talk probably about the most common issue – why your uPVC door won’t lock when closed.  

uPVC door won’t lock when closed: causes and solutions

You see, uPVC doors aren’t like ordinary doors. They require more attention in terms of maintenance and certain issues may arise over time, including the door not being able to lock properly or the key spinning in the lock.

Changes in the weather

Weird as it sounds, the weather can actually be the reason why you have troubles properly closing your uPVC door. Basically, when it gets a bit warmer or colder than normal outside, the door starts to shrink, contract, and then – expand. It’s only by 1mm or 2mm, but that’s quite enough. Changes in temperature also speed up the process of uPVC door drop, but more on then in a bit.

How to fix it?

If your uPVC door isn’t closing properly due to weather conditions, one of the things you can do is wait for the temperatures to get back to normal. We understand that this isn’t the best-case scenario, especially regarding the security of your home. You can also try wetting a piece of cloth with cold or hot water, depending on if your door expanded or shrunk, and applying it to its surface. 

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Dropped door

This is probably the most common reason why your uPVC won’t lock when closed. What happens is that the locking points keep misaligning, making the door harder to open and close.

How to fix it?

In order to realign a dropped door, you have to adjust the hinges. That said, there isn’t only one type of hinges, but three – flag hinges, t-hinges, and butt hinges. And that’s not even all of it – each type of hinge has a different sort of adjuster that moves the door in a specific direction. Don’t worry – it’s not as complicated as it sounds. Now, here is what you need to do in order to fix each type: 

Flag hinges

Flag hinges have 3 sorts of adjustments: a height, lateral, and compression adjuster. As you’ve probably already guessed it, we are going to be working with the height adjuster. You will find the part located on the bottom section of the hinge, hidden under a removable plastic cap.

Now, what you are going to need for the job is a 5 mm Allen wrench. Insert the wrench into the adjuster and start turning it clockwise until the door lifts up back to its place. Once you are done, try to lock the door. If you still have a hard time closing it, adjust the height again. Make sure to adjust all of the hinges.


Similar to the flag hinge, t-hinges also have different kinds of adjusters – a height and lateral one. Basically, what you have to do is, like for the flag hinges, locate height adjuster and turn it until the door is in the right position. Again, don’t forget to adjust the height of the other hinges, too. 

Butt hinges

If you have an older uPVC door model, chances are it does have butt hinges. And do you know what butt hinge DON’T have? Height adjusters. In translation – if your door has dropped, you’ll have to reinstall the whole thing to fix it, and that can be only done by a professional. 

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Broken locking mechanism

A uPVC door locking mechanism is a very intricate and capricious thing. Over time it becomes weak and can break from the pressure of everyday use.

How to fix it? Once it breaks, you need to change it, so to make sure that doesn’t happen. Keep the lock well-lubed with WD-40 and don’t apply force when raising the handle.

Like we said earlier, some types of uPVC door repairs you can actually do yourself, while others are best left to be performed only by a professional. A broken lock mechanism falls exactly into that category. You can read more about why that’s a complex issue in our guide below.

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Faulty euro cylinder

Another very common issue is a faulty key cylinder. Such a problem can lead to not being able to lock the door properly or ending up with a stuck key. If the second has already happened to you, check our in-depth article on how‌ ‌to‌ ‌get‌ ‌out‌ ‌a‌ ‌key‌ ‌stuck‌ ‌in‌ ‌the‌ ‌lock‌.

How to fix it? Try a lubricant such as WD-40. It can penetrate and loosen the internal workings of the stuck cylinder. You might have to spray several times until the lubricant manages to penetrate deep enough to the root of the problem. However, it’s also possible that it won’t work and you’d have to change the entire lock.

Key doesn’t work

If you’ve recently had a new key made, it could be poorly cut and thus causing problems inside the lock. Or maybe you’ve had a new cylinder fitted, but the spindle has been cut too short. If the key cannot turn at all, you’re either using the wrong one or an interior snib could have been engaged by accident.

How to fix it? Don’t use force, that will likely break the key while it’s still inside the lock. Try to spray some WD-40 in the lock to see if you will manage to turn and get the key out.

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Get a professional to fix the uPVC door for you

Trying to repair a uPVC door that won’t lock is hard, and frankly – sometimes impossible. So, no matter if your door has dropped or the locking mechanism decided to break, don’t worry as we’ve got a solution for every problem. Don’t bother yourself trying to figure out what type of door hinges you have and book our door repair services for a quick and easy fix.

The service is performed by especially trained and highly experienced London locksmith professionals, has a 6-month workmanship guarantee, and also happens to be available 24/7! How awesome is that?

And if you’re wondering how much a locksmith costs to fix your issue, our blog post on the matter has the answers!

Your uPVC door won’t lock?

Fantastic Services is here to help you.

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  • Don’t try to forcefully lock or close the door. This will cause only further damage and make repairs harder and costlier. 
  • Make sure adjust all of your uPVC door’s hinges, otherwise, it still won’t close and lock properly. 
  • If you have any lock mechanism issues, it’s best to leave the repair job to a professional, so you don’t create a bigger problem. 


Did you find our article helpful? Make sure to leave a comment below, sharing your personal experience! 

Image source: Shutterstock / HDesert

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