Home Improvement

uPVC Door Lock Mechanism Broken? Here’s What to Do!

Are you having trouble with your uPVC door lock mechanism? Are you unable to open the door or is there another issue that you wonder how to fix yourself? No worries, because you’ve come to the right place. From this post, you will learn:

  • how uPVC door locks work,
  • what some common lock problems are and how to fix them,
  • how to thoroughly replace the lock if needed, and
  • how much a professional locksmith may cost you.

How do uPVC door locks work?

In order to understand the uPVC door locking mechanism, you need to get familiar with the type of locks used. Contrary to popular belief, however, not all lock types are suitable for all types of doors. UPVC doors require a special type of lock and you need to know exactly what type your door has so you can get the right replacement.

What type of lock is on a uPVC door?

Multipoint locks are most commonly used on uPVC doors, however, a night latch locking system, euro cylinder lock and other types could be also installed. That being said, there are also different types of multipoint locks.

You can check yours by opening your door and examining the long metal strip that bolts into the side of the door. If it has multiple points, all of which lock the door, then it’s a multipoint lock. You can distinguish the types by counting their locking points (there are usually three, but could be more).

Multipoint locks have one lock cylinder, which may be convenient for you, but it makes it a bit easier for problems with it to occur. Common problems such as uPVC door not locking when closed are fairly easy to fix but some require help from a professional.

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UPVC door locking mechanism problems & repairs

Lock mechanisms see a lot of usage, which makes them prone to various problems. UPVC door lock problems can differ and can also be caused by weather conditions, improper usage or they simply weaken with time.

Of course, if you hit, kick or slam it hard, the lock is likely to break beyond repair and you’ll need to replace it with a brand new one. But if that’s not the case and your door is hanging, the lock isn’t working, key keeps turning in the door lock or you simply cannot open the door, then keep reading.

So if your uPVC door lock is broken or there’s another problem, here are some of the most common ones and what to do about them as a homeowner.

#1. Loose door handle mechanism

A floppy door handle mechanism is a common problem. It can be easily fixed by you. You need to find the barrel and the screws that hold the lock in place. When you locate the screws or screw, tighten it with a screwdriver. This tightens the loose door handle and your door should now work properly.

On the other hand, you can also try loosening the handle screws in case the door is stuck. Oftentimes screws that are too tight might pinch the lock, leading to you not being able to open the door at all.

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#2. A faulty lock cylinder

Oftentimes, lower-quality locks may have a faulty cylinder or they may break due to excessive usage. You can test this easily and rule it out. Insert your key and try to turn it. If it moves freely but the door won’t open or close, then the problem isn’t with the cylinder.

If the problem is with the cylinder, fixing it can be a cheaper option. You can buy and replace the cylinder only and not purchase the entire locking mechanism. You’ll also need to change the keys, so keep that in mind.

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#3. Stuck uPVC door lock mechanism

If the uPVC door lock mechanism is sticking, the reason can be unlubricated or broken internal hinges. To find out what is making the mechanism stick, you’ll have to take it out to inspect it. However, if you’re not skilled at DIY handyman work, you should call a licensed professional to do it.

If you decide to do the work yourself, inspect the hinges and if they need lubrication, you should lubricate them and see if the problem is fixed.

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#4. Broken gearbox

How to open a uPVC door with a broken gearbox? Do not try to force it open. This will result in breaking the door as well as the lock. There are a few things you can check that could be the reason for a broken gearbox, however, this isn’t a problem you can fix yourself.

Regardless of the reason the gearbox is broken, you’ll need to use tools that only professional locksmiths have. If this is the problem your door has, then you should call a locksmith as soon as possible.

Learn how the 24/7 locksmiths in London can help you out.

How to replace a uPVC door lock mechanism

It is possible to replace the locking mechanism of a uPVC door, however, in order to do so, first, you need to know how to remove the old uPVC door lock mechanism.

Time needed: 1 hour.

  1. Prepare the tools.

    You’ll need a drill, a screwdriver, tape measure, a rubber mallet. 

  2. Remove the uPVC door lock mechanism.

    Use the screwdriver to unbolt the old lock and take it out of the door. Disassemble the handles and wiggle the mechanism out of the door.

  3. Identify your lock.

    Find the manufacturer’s name and mark on the faceplate if you want to buy from the same manufacturer. Buying the same brand will make it easier to fit the new lock because it will have the same dimensions, whereas locks from other manufacturers may be slightly different. 

  4. Measure before you replace the broken lock mechanism.

    Measure the main dimensions of the locking mechanism to get an exact-match lock or simply take the lock with you to the store.

  5. Replace the uPVC door lock mechanism.

    Insert the locking mechanism inside the door and then tighten the screws. If you’re having difficulty inserting the mechanism into the door, you can use the rubber mallet to gently hammer it in place. Then, adjust and tighten the handles.

  6. Test the lock.

    Do this with an open door. Insert the new key into the cylinder and turn it. Does the tongue come out properly? Does the key turn easily? 

Keep in mind that DIY lock replacements could lead to damaging the new mechanism, and make the job of the professional locksmith harder.

How much does it cost to change a lock on a uPVC door?

Changing a lock by yourself may be cheaper but it doesn’t have the many benefits as leaving it to a professional locksmith. In fact, if you’re not experienced enough and want to change your first lock, you may end up causing more damage and spending more money on fixing the problem than the initial lock replacement would have cost you.

Book a professional locksmith with Fantastic Services and take advantage of emergency appointments with a 30-minute response, and a 6-month guarantee for the work done. The price for the service may vary depending on whether the uPVC lock can be repaired or needs to be directly replaced, but you can expect prices from £59 for changing an existing lock and £71 for repair.

Want to know more about locksmith prices and how are they formed? Read further on How Much Does a Locksmith Cost In the UK?

Need a certified locksmith near you?

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  • Any lock type can become damaged after some time and usage. It’s important to act fast. 
  • Paying a professional locksmith to fix the problem is often the safest, fastest, and in retrospect, the most cost-effective solution to such a problem.
  • DIY uPVC lock replacement is possible if you have the knowledge and the right tools. 


Did you find out what’s the reason for your broken uPVC door lock mechanism? Share your experience in the comment section below!

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