Help! My patio door won’t lock – what do I do?
If your patio door won’t lock, it can be a real headache. You need patio doors to open and close efficiently and lock properly for safety reasons and to keep the elements out.
But just like other parts of your home, over time, doors and locks can show signs of wear and tear and potentially go wrong.
So whether you have a stubborn uPVC door handle, a patio door that refuses to shut tight, or your sliding glass door won’t lock, we’re here to help.
Where to start if your patio door won’t lock
When it comes to reopening patio doors after being locked for winter, you might come across a few problems.
This could be a minor issue such as moving parts seizing up due to rainwater getting in – in which case, oiling the lock might do the trick.
A uPVC door not locking in cold or hot weather is a very common problem that locksmiths often get called out to fix.
As a starting point, first check:
- Is the lock obstructed? Check all around the door to see if anything is trapped or blocking the lock
- If your sliding door won’t lock, check it hasn’t come off its track. Making sure the door slides freely will mean it can lock properly. You might need to get in touch with a patio door repair expert to help with this
- Hot weather and direct sunlight can cause patio doors to expand and cause issues with locking. Try cooling down the door with cold water to get the door back to normal size
Reasons why your patio door won’t lock
As mentioned previously, wear and tear, hot weather, and obstructions can lead to issues with your patio door not locking.
Check out these common causes for your patio door not locking:
Misalignment
Patio doors are made up of several different parts – and they all need to fit together to work smoothly.
For example, a door handle that won’t lift up to lock when your uPVC door is closed (but lifts easily when the door is open) might mean the door needs adjusting. Sometimes the lock latch might need adjusting too.
For this sort of problem, we recommend calling in an expert who can professionally adjust your patio door.
Debris in the lock
Dirt, dust, and debris can build up in the lock mechanism and make it stick or not shut properly.
Check the frame and locking points for any debris or small stones/gravel that might be causing an obstruction.
Faulty or worn parts
Over time, the moving parts of a patio door will wear and can lead to problems with a door locking.
A gearbox failure is one of the most common parts that might need fixing or replacing. Located inside the door, the gearbox is a smaller part of the multipoint mechanism that turns a number of rollers, hooks, and bolts. It ensures the door is securely locked.
Most locksmiths will carry a large range of gearboxes with them to solve this issue. Sometimes the locksmith might need to replace the entire multipoint lock if it’s damaged or broken.
Other potential reasons your patio door won’t lock:
- Key stuck in the lock
- Alignment of the strike plate
- Broken key
- Dropped door
- Full uPVC lock mechanism replacement
- Jammed lock
- The weather has caused expansion/contraction
Solutions for fixing patio doors
If your french door won’t lock or if you have malfunctioning sliding doors, here are some common solutions for fixing the problem:
1. Realign the doors
If your patio door isn’t aligned properly, it will likely need to be properly adjusted.
This could be down to expansion because of hot weather or the door might drop if fixings become loose.
Even if your doors have only shifted slightly, the locking points might not meet as they should.
This can be a complex process and can include taking all the mechanisms apart including removing panels and hinges from the door.
For this reason, we recommend getting in touch with a local patio door repair expert who can make the adjustments.
2. Clean and lubricate the lock
Begin by removing any visible dirt and debris from the locking mechanism using a soft brush or damp cloth. For hard-to-reach areas, consider using a can of compressed air to blow away any stubborn grime.
Once clean, lubricate all moving parts with a light machine oil. Then turn the lock from a locked to an open position several times to work the machine oil into the mechanism and keep the parts running freely.
3. Check for worn components
Assess the condition of the components in your door lock, especially if you have an older door.
Check for signs of wear on the handle, cylinder, and lock hardware. And if any parts appear damaged or worn, it may be time to replace them.
We recommend hiring an expert who will be able to assess why your patio door won’t lock and address any worn or damaged parts.
If you believe your patio door is beyond repair, head to our cost guide for replacing a patio door to help understand the average prices for this.
How to fix a patio door lock
You might be able to save yourself some money by fixing a patio door lock yourself – especially if you are a competent DIY-er and know what the underlying problem is.
So if your patio door lock is sticking or giving you a hard time, fear not. Here’s how to bring it back to life with a little TLC:
- Gather your tools: You’ll need a screwdriver, lubricant, and a bit of patience
- Disassemble the lock: Carefully remove the lockset following the manufacturer’s guidelines
- Clean and lubricate: Thoroughly clean the components and apply a recommended lubricant to ensure a smooth operation
- Reassemble the lock: Put the lockset back together as you found it, making sure each piece is snug and secure
How to fit a patio door lock
Installing a new lock? Let’s fit it perfectly to make sure your patio’s security is top-notch.
- Choose the right lock: Depending on your door type, select a suitable lock. For example, lever locks for swinging doors, mortise locks for sliding ones etc.
- Read the instructions: Don’t skip this step – each lock has a unique installation process you need to follow
- Measure and mark: Use a tape measure and pencil to mark the right position for your lock on the door
- Drill and install: Carefully follow the instructions for drilling holes and attaching the lockset
- Test and adjust: Test the lock’s functionality and make any necessary adjustments for a perfect fit
How to replace a sliding patio door lock
If your sliding door lock is showing signs of wear or simply isn’t up to the task anymore, it’s time to replace it.
- Remove the old lock: Unscrew and remove your current lock (follow the manufacturer’s guidelines!)
- Measure twice, buy once: Measure the dimensions of your old lock to make sure your replacement will seamlessly fit
- Install the new lock: Attach the new lock, making sure it’s level and secure
- Test and verify: Test the lock to make sure it engages and disengages smoothly before patting yourself on the back
If in doubt, lock in the help of a professional in your local area!
How much does it cost to replace a uPVC door lock?
The average cost of a uPVC patio door lock replacement is £110, plus the cost of labour.
The typical locksmith hourly rates are on average £75. If you wish to get your uPVC door lock changed, that takes around 1 – 3 hours generally, depending on various factors.
Of course, if you want your door locks changed out-of-hours, that would cost you more per hour. Most locksmiths’ hourly rates for such a situation would be between £75 - £125.
Wondering how to find trusted, experienced professionals to get your patio doors working smoothly again? Checkatrade can help.
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