Find out why your uPVC door won't lock

A fully functioning lock is an important part of your uPVC door, but it can sometimes experience issues. If you’re wondering why your uPVC door won’t lock, keep reading to find out what the problem might be so you can get it fixed.

By understanding why your uPVC door won’t lock, you can take the appropriate action to resolve the issue and get back to having a door that fully locks.

In this guide, we’ll look at the effects of temperature, alignment, door position, locking issues, access, and more. So, let’s get started…

Common reasons why a uPVC door won’t lock

To help you determine what might be wrong, here are some of the most common reasons why your uPVC door isn't locking:

• Misalignment – Your door or frame may have moved due to impact or wear and tear, causing the lock to be misaligned

• A faulty lock mechanism – Some of the internal components of the lock system could be damaged or worn out and need changing

• Issues with the key – A damaged or worn key or a faulty lock cylinder could be the problem

• Weather-related movement – During hot and cold weather, uPVC doors can expand and contract resulting in temporary misalignment

• An obstruction – A build-up of dirt, debris, or small objects can get stuck in the lock or hinges, preventing it from working

• Hinge issues – Stiff or damaged door hinges can cause your uPVC door to misalign and stop it locking

• Warping – Prolonged exposure to moisture can lead to warping or swelling that affects the locking mechanism

Make sure you check all of these possible causes to identify exactly why your uPVC door won’t lock.

What to do if your uPVC door lock mechanism is broken

Learn the best way to fix a upvc door lock mechanism to make sure your home and its contents are safe and secure.

Learn more

Temperature-related locking problems

Throughout the year, temperature changes can cause issues when it comes to a uPVC door locking properly:

My uPVC door won’t lock in the heat / hot weather…

If you find that your uPVC door won’t lock when hot (due to hot weather or your home’s heating), it will likely be due to the door or frame expanding.

Higher temperatures can cause your uPVC door and/or frame to swell, leading to locking issues.

My uPVC door won’t lock when cold…

In contrast to heat, cold weather can cause your uPVC door and/or its frame to contract.

As a result, the door can end up sitting differently, leading to alignment issues. The cold can also lead to stiff locks that don’t work properly.

Locking issues based on the door’s position

Sometimes you’ll find that the door won’t lock fully because of the position it’s in, i.e. open or closed:

My uPVC door won’t lock when closed…

If your uPVC is closed but won’t lock, there are a few possible explanations, such as:

• The door is misaligned

• Warping has caused the door to get stuck

• It has a faulty locking mechanism

• An obstruction is blocking the locking system

If you can open the door, give it a close inspection to see what might be causing the issue.

My uPVC door won’t lock even when open…

Often, if your uPVC door won’t lock even when open, it usually means there’s an issue with the internal lock mechanism.

If it’s the lock itself that is broken or damaged, it will stop the door locking regardless of whether it’s open or closed.

Locking issues based on access

Occasionally uPVC doors can have locking issues that only affect a certain way that you’re trying to lock the door:

My uPVC door won’t lock from inside…

If your uPVC door will lock from the outside but not from inside, it’s likely to be one of the following issues that you’re dealing with:

• A faulty or worn key cylinder that means the external lock mechanism is damaged

• Broken or disconnected external handle that isn't engaging the lock

• Incorrect or worn key for the external lock

Help! My patio door won't lock - what do I do?

It can be really frustrating if your patio door won't lock. But help is at hand with our troubleshooting guide which is packed with tips to help solve the issue.

Learn more

My uPVC door won’t lock from outside

When the door locks from the inside but won’t lock from the outside, it could be because of the following:

• Internal handle malfunction due to being damaged or disconnected

• Locking mechanism issues, such as the internal parts aren't engaging when the inside handle is used

• Misalignment of the door means the internal locking points aren't aligned properly either

• A faulty or worn key cylinder that is affecting the internal locking mechanism

My uPVC door won’t lock with the key…

If the problem with locking your uPVC door only happens when you’re trying to use the key, the cause could be one of the following:

• A worn or damaged key that’s been bent, worn out, or not cut properly

• A faulty lock cylinder that could be jammed, damaged or misaligned

• Debris in the keyhole that’s stopping the key from turning properly in the lock

• Misaligned door or lock points that aren’t lining up correctly

• Broken internal components of the lock are damaged or worn out

It might not be immediately obvious if there are internal issues with your door’s lock. So, you may need to call upon the help of a professional locksmith:

Handle-related locking problems

The handle can often be the culprit of why your door won’t lock:

My uPVC door handle won’t lift up to lock

Often it’s the door handle that doesn’t lift properly, meaning you can’t lock the door:

• Locking mechanism misalignment can stop the handle from engaging

• Handle mechanism failure due to internal parts breaking or wearing out over time

• Jammed lock points caused by debris and/or a lack of suitable lubrication

Replacing a uPVC door handle: What you need to know

Replacing a uPVC door handle is a lot easier than you might expect. Here’s all you need to know.

Learn more

My uPVC door won’t lock when I lift the handle…

If you can lift the handle but the door won’t lock, chances are it’s an issue with misalignment or damaged internal components.

What to check when your uPVC door won’t lock

Whether your door handle won’t lift up to lock, or it won’t lock with the key, here are some quick checks to make:

• Check the door alignment for any signs of sagging or misalignment from the frame

• Inspect the door frame, hinges and locking system for any noticeable dirt, debris, or objects that could be blocking the door

• Test the key by turning it in the lock – if it’s stiff or doesn’t turn then the lock cylinder may be faulty

• Examine the locking system to see if there are any signs of damage or loose bolts, hooks or rollers

• Check if the hinges need tightening or adjusting to align the door properly

• Try operating the handle and lock to see if it sticks – if it does, check out our guide on what to do when your uPVC door lock is sticking

By carrying out these checks, you can often identify why your uPVC won’t lock. And then take action.

But, if you still can’t figure out what the problem is then it might be time to call for professional help.

Find the best locksmiths near you

If you need help with your uPVC door lock, we can help you find approved locksmiths in your area.

And, if you hire one of our Checkatrade members, you’ll have peace of mind that you’re hiring an approved tradesperson who has passed our checks.

Ready to get started? Enter your postcode in the box below to browse a list of approved locksmiths in your area: