How to Open a Jammed, Stuck, or Seized uPVC Window

Last modified on December 30th, 2022

I couldn’t open the window, it was stuck, jammed and seized shut. The window handle moved, but the window just won’t open?

When you close the window, the gearbox (which is attached to the handle) pushes shootbolts (espag or espagnolette) and roller cams (mushrooms) out to lock the window in the outermost corners. Parts of the gearbox can break, or the shootbolts can seize preventing the window from opening.

Video: How to Open a Window That’s Stuck (Difficult to Open Example)…

Topics:

• Videos:
  • Difficult to Open Example:
  • Easy to Open Example:
• uPVC Window Lock Faults:
• uPVC Window Lock – Parts Description:
• How do I Open the Jammed or Seized Window?
  • What Tools do I Need?
• Inserting the Opening Tool in the Window Gap:
• Opening the Jammed uPVC Window:
• Video Examples:
• Repairing a Jammed or Stuck uPVC Window:
• Ordering Parts (Gearboxes, Shootbolts, Handles, etc):
• Opening a Jammed uPVC Window – Hints and Tips:

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uPVC Window Lock Faults:

The window handle gearbox can break (which is often the case), or the shoot bolt (espag or espagnolette) and roller cams (mushrooms) jam or seize. When the gearbox breaks, it doesn’t allow the shoot bolts and the roller cams to return to the open position, and the window won’t open.

Typical Window Gearbox Faults:

This image shows a lug that has broken off. The gearboxes use cast components which can be brittle.

And this image shows the operating arm broken away from the window gearbox.

uPVC Window Lock – Parts Description:

Note: The parts below are for illustration only, as they come in different shapes and sizes from various manufacturers… uPVC and PVCu are the same material, just a different pronunciation.

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How do I Open the Jammed or Seized Window?

How to Open a uPVC Window with a Broken Gearbox?

It’s a fairly easy process to open the window. The difficulty is when there is:

• Only a small gap to insert a simple tool,
• Or, the roller cam is stiff to move (corroded or seized).
• Parts are missing (roller cams).

Precautions

It may seem daft, but… Please don’t fall out of an open window, it’s easily done. Be careful, be safe!

• uPVC windows are made of soft plastic and can easily be damaged, scratched or gouged.
• When working on a window, beware of dropping tools and other things out of the window. “Lucky” the cat might not be so lucky..?

Any modifications are at your own risk…

Easy to Open Example (Difficult to Open Example above):

The text and images below, describe how we open a jammed or stuck window…

What Tools do I Need?

You will need something fairly thin bent at a right angle. You could use a:

• Bent nail.
• Allen key.
• Or a pick.
• And pliers to help pull the tools.

Once you have your tools, it’s trial an error to see which one fits best? Each window may have a different size gap between the window and frame, (and the gap can be different from one end of the window to the other…).

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Inserting the Opening Tool in the Window Gap:

Where do I Insert the Tool?

The shootbolts are towards the opening ends of the window, above and below the window handle (side-hinged window), or to the left or right of the handle (top-hinged window) – See the image below.

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Opening the Jammed uPVC Window – Moving the Shoot bolt Roller Cam:

1. Put the window handle in the open position. This will move any working shootbolts to the open position.
2. Insert a right-angled tool just past where the shoot bolt roller cam is likely to be (so the roller can be pulled towards the window handle – See the images below).
3. Push the tool between the window and the window frame, past the rubber seal. Be careful not to damage the seal or the plastic window.
4. Turn the tool through 90 degrees. Gently pull the tool towards the shoot bolt roller (in the direction of the window handle). Position the tool so it runs along the edge of the window. This is to ensure you don’t miss hooking the roller cam.
5. You should then feel the tool stop as it hooks the shoot bolt roller.
6. Pull the shoot bolt roller cam towards the window handle.
7. The shootbolt roller should move and release this end of the window.
8. Repeat if the opposite end of the window is also jammed?
9. The window should now open.

Notes:

• If needed, have a look at another window (on the ground floor) that has the same mechanism, to familiarise yourself with how the lock works and where all the parts are fitted.
• Make sure you are pulling in the right direction (in the direction that the shootbolts move to open).
• Both shootbolts can get stuck, so you may need to release both sides.
• Don’t forget to make sure the handle is in the open position, when trying to open the window that is jammed.
• Use some cardboard or something similar between the window and your tools to try and protect the window from scratches.
• If needed, use a screwdriver to increase the gap to get the tool in.
• You may need to use a pair of pliers to grip the allen key (or right angle tool).
• You may need to remove the window handle if it gives you more room.

It can sometimes be a very easy job. It’s difficult when you can’t get the tool in the small gap, or the shootbolt mechanism is stiff or seized.

Opening a Stuck PVC Window – Demonstration (with an open window)

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Repairing a Jammed or Stuck uPVC Window:

The repair will usually involve:

• Closing the window.
• Freeing up or replacing the shootbolts and rollers.
• The replacement of the locking mechanism gearbox, as lugs can break off within the gearbox.
• Checking the connection between the locking mechanism gearbox and the shoot bolts.
• Getting Parts:

Closing the Window:

When you manage to get the window open, Don’t try and close the window straight away. The mechanism will still probably be faulty…

Therefore:

• If you close the window, it may get stuck again!
• You may not be able to close the window, unless you remove the offending parts.

Note:

• As a temporary solution, you can often refit the shoot bolt gearbox, without the shoot bolts (espag or espagnolette), so your window will still close and lock (by the handle latch only) whilst you wait for parts.

Freeing up or Replacing the Shootbolts and Roller Cams.

The shoot bolts and their rollers can become seized or corroded, as they are usually manufactured from mild steel with a thin electroplated finish.

Free up the parts, clean and protect from further corrosion. Lubricate, or replace as necessary.

Notes:

• Silicone grease is a good lubricant for windows. It less likely to get washed away, won’t damage any rubber seals and is usually a transparent white colour (often used in plumbing applications).
• Silicone grease shouldn’t stain the plastic. Whereas, regular oil and grease can stain and leave marks, even when wiped away.

Replacing the Window Locking Mechanism Gearbox:

Lugs can break off within the gearbox, or the casting can just fracture. To replace, remove the window handle and loosen the shoot bolts. You can then slide the gearbox out of the window frame (see the images below).

When you replace the gearbox, you can insert the gearbox in the window frame the wrong way round. All this does is change the direction that the window handle operates. Try the handle in the gearbox before you fit it in the window, or just turn the gearbox through 180 degrees.

Note:

• The parts are often fixed in place with screws, but can be pop riveted. In which case the pop rivets will need to be drilled out…

Checking the Connection Between the Locking Mechanism Gearbox and the Shoot bolts:

In some instances, the shootbolt can become disconnected from the handle gearbox. Refit, checking that the connection lines up correctly and is secure.

Note:

• When uPVC windows are manufactured, the shoot bolts are sometimes cut to length to fit the window. In some cases, they can be cut too short and can jump out of the housing. If this is the case, the shoot bolt (espag or espagnolette) may need replacing.

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Ordering uPVC Window Parts (Gearbox, Handles, Shootbolts, etc):

The main thing when ordering parts, is to compare the new part with the original. New parts may get modified as they improve and evolve (you would hope), but some key things should stay the same. For instance, the size and position of fixing holes (the part has to fit in the original position and the fixing holes need to be the same).

So, measure the size of your old parts, the position of fixing holes and the type of connections (how the other window parts may attach to the replacement part).

When ordering gearboxes, you will often see quoted “A 9.5mm, or 11.5mm latch and 20mm, or 22mm backset is available”. The image below gives an example of a 11.5mm latch with a 22mm backset. Therefore take care when measuring these particular sizes.

Ordering Parts – Examples of What You Can Buy:

Window Parts
Item	Location
Gearboxes	UK Prices
	US Prices
	IE Prices
	CA Prices
	AU Prices
Handles	UK Prices
	US Prices
	IE Prices
	CA Prices
	AU Prices
Shootbolts	UK Prices
	US Prices
	IE Prices
	CA Prices
	AU Prices
General spares	UK Prices
	US Prices
	IE Prices
	CA Prices
	AU Prices

Notes:

• You can also get ‘Cranked’ and ‘Straight’ faceplates, where the shoot bolt connections are raised or straight. They can have the code ‘05058’ (Cranked) and ‘05060’ (Straight) written where the shootbolt connects to the gearbox.
• Check the gearbox for markings that may also indicate the sizes, such as ‘095’ for 9.5mm. Take measurements to confirm, in case it just happens to be a random casting serial number, or something similar!

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Opening a Jammed uPVC Window – Hints and Tips:

If it helps, practice on an open ground floor window (that has the same fittings), to see how the mechanism works and where all the parts are. It may give you an idea on what’s needed to open the stuck window. You will probably need to operate the window handle at the same time when testing. With the windows that are stuck shut, make sure the handle is in the open position (when trying to open).

As usual, any work is at your own risk… Please be careful, as it’s very easy to fall out of an open window. Be safe!

1. Place thin cardboard against the window to help protect the plastic…
2. When trying to open a stuck window, make sure the handle is in the open position…
3. Which way round do the window handles go?
4. My upvc window lock does not have the mushrooms but the locking mechanism is the same style. Any idea what I could do?
5. I have windows with the shoot bolts but not the rollers and one of the shoot bolts is not unlocking?
6. When I get the window open, will I be able to close it?
7. My window is open and it won’t close?
8. I am unable to twist the allen key, probably not enough space between window and the frame… any suggestions?
9. Will this work on a door?

1. Place thin cardboard against the window to help protect the plastic…

Thin cardboard can protect the soft window frame plastic from getting damaged. You could hold the cardboard in place with masking tape.

2. When trying to open a stuck window, make sure the handle is in the open position…

Don’t forget to make sure the handle is in the open position, when trying to open the window that is jammed.

3. Which way round do the window handles go?

For vertical windows’ it’s easy, as the handle normally point downwards. For top hung windows (horizontal), imagine for a moment that you have turned the window sideways, and the window is now side hung (vertical). This gives you a good idea which way round the handle should go.

4. My upvc window lock does not have the mushrooms but the locking mechanism is the same style. Any idea what I could do?

Have a look at another window (with the same mechanism) to work out if there is a method of opening – Choose a window on the ground floor, as you don’t want to fall out the window!

There may be some holes somewhere in the mechanism (shoot bolts) that you could grab with a pick. Practice, investigate with another open window (on the ground floor) to see if you can to work out a method of opening?

Removing the handle or jiggling it around whilst using a pick may help?

5. I have windows with the shoot bolts but not the rollers (roller cams, or mushrooms) and one of the shoot bolts is not unlocking. I had a look at one of the other windows at my house and can’t think of a way of pushing them in with the window stuck shut. Any ideas?

5.1 – Looking at another window (on the ground floor, so you don’t fall out!), are there any holes where rollers could have been fitted? You could try and make a ‘u’ shaped tool to grab the shoot bolt. If there is absolutely nowhere to grab the shoot bolt and there is no way of hooking it, then the only option may be to grab it from the other side?

5.2 – If you remove the glass:

• Pull out the rubber seal between the glass and plastic bead (to give some extra wriggle room).
• Remove the plastic beads from around the frame and glass edge, (older windows the bead removes from the outside, newer windows the inside).

With the glass removed, the frame should flex a bit more. Be careful though as things can break (the plastic welds holding the window together can be brittle and the hinges can break). You might be lucky if the window frame flexes a bit, and the shoot bolt is only just latching?

5.3 – Warning – I have never done this, (and it is the last resort). The whole window frame is usually held in place by drilling through the plastic frame and fixing into the wall using long screws. On the same basis, if the shoot bolt needs a small hole drilled in it, you could remove the glass and drill through the frame (in the area normally hidden when from the glass is fitted). Choose the best position to drill through carefully by comparing the shoot bolt position on another window (on the ground floor).

If the shoot bolt still cannot be moved using a pick, make the hole you’ve just drilled in the plastic frame bigger (slotted). The aim is to make a hole so that the shoot bolt can be levered up. Any hole(s) you drill will need to be hidden by the glass and shootbolts (when replaced).

6. When I get the window open, will I be able to close it?

If it’s the gearbox that’s broken and it’s not operating the shootbolts properly (the shootbolts are moving in both directions):

• You can remove the shootbolts (top and bottom, or left and right for top hung windows) and just leave the window lock (next to the handle) in place.
• The window should still open and close.
• Check that the window lock operates freely when you have removed the shootbolts.

Note: Your house insurance may stipulate the type of locking mechanism that should be fitted to a window. So you may need to replace the broken parts.

7. My window is open and it won’t close?

The gearbox fitted inside the window (the handle shaft passes through it) has probably broken. To shut the window, you will need to remove the shootbolt(s).

Notes:

• Check both shootbolts, as both may not be operating.
• The shootbolts are normally held in place by screws, but are sometimes pop riveted.
• If you manage to move the shootbolts (and haven’t removed them) and then shut the window, it probably won’t open again by the handle (because of the broken gearbox). You will then have to get the window open again. Test the window mechanism in the open position.

8. I am unable to twist the allen key, probably not enough space between window and the frame… any suggestions?

Sometimes you have to use a screwdriver to increase the gap to get the tool in, and use a pair of pliers to grip the allen key. Use some cardboard or something similar between the window and your tools to try and protect the window from scratches.

• Have a look at another window (on the ground floor) that has the same mechanism, to familiarise yourself with how the lock works and where all the parts are fitted.
• You may need to remove the window handle if it gives you more room.
• Make sure you are pulling in the right direction (in the direction that the shootbolts move to open).
• Both shootbolts can get stuck, so you may need to release both sides.

9. Will this work on a door?

I’ve never tried to open a door, but if it has the same type of mechanism as the window in this article, then there’s is no reason why it won’t work. The shoot bolts on a door normally operate when you lift the handle (rather than pushing down the handle to open the door). So when you try and move the shootbolts with a tool, make sure the handle is lifted. You will then have to hold the shootbolt in the open position whilst you use the handle to open the door (doors and windows have two shootbolts. Hence needing to hold the shootbolt open whilst you move the other with the handle). Note – Just one, or both shootbolt mechanisms could be broken?

Back to the top of the list (Hints & Tips)…