How to Diagnose and Replace a Broken Boltlock Snib

A broken boltlock snib could be a sign of an underlying issue with your sliding or stacking door, such as out-of-alignment rollers, loose keepers, or a problem with the lock body. We asked our friendly service team for some advice if this is happening to you.

What is a boltlock snib?

Boltlock snibs, sometimes called snib locks, are the little levers on your door handles that are used to lock or open your sliding doors. They come in two sizes.

1. Top snibs are larger and are used to open the door from inside or outside the house.
2. Bottom snibs are smaller and are used to lock the door from inside the house. The bottom boltlock snibs rarely break, but will on occasion if taken out and used as a top snib.

Top snibs are larger and are used to open the door from inside or outside the house. Bottom snibs are smaller and are used to lock the door from inside the house.

Three potential causes of a broken snib

Boltlock snibs are easy to replace but it’s a good idea to diagnose the cause of a broken snib so it doesn’t become a recurring problem.

Our friendly service team highlights three of the most common causes of broken snibs:

1. Rollers need replacing
2. Keepers need replacing
3. Lock body needs replacing

Clean the door tracks regularly to enable your door to slide smoothly along the door track. Download our Maintenance Guide to learn more.

1. Check the rollers run smoothly and the door is level and square

Sometimes if the door is not level and square the snibs can break, as the locking rods that run up and down the front door stile (piece of aluminium that the handle is screwed onto) drops down, putting pressure on the snibs and causing them to break.

If your door is not level you may need to adjust the rollers. You can adjust the screw clockwise to raise the roller, or anticlockwise to lower the roller.

• Clockwise adjustment is usually required, as the rollers have more likely dropped
• Adjust the roller and gently manoeuvre the snibs until they feel like they are moving smoothly
• Replace the roller wheel if it looks damaged and does not roll correctly

2. Check the keepers are secured into your door frame

If you have a Jason Windows Boltlock Sliding Door from 2000–2009, check the keepers are secured into your door frame properly. Keepers are located in the top and bottom of the frame and allow your door to be locked in a partially opened “vent” position, encouraging airflow but maintaining security.

If the keepers are loose or have come away from the jamb (the sides of the frame) this can put pressure on the lock body and cause the snibs to shear.

• Replace the keepers if they look damaged

3. The lock body may need to be replaced

If you have tried adjusting the rollers and checked that the keepers are in the correct position but you are still having troubles, the lock body may need to be replaced.

• Watch the above video for a DIY guide on how to change the lock body.

Preventative Maintenance

If your rollers, keepers and lock body are all in good working condition but the snibs still break it could be due to one of the following:

• The tracks, keepers and rollers may need cleaning to help the locking rods move freely
• The snib is inadvertently being pulled or forced when the door is being opened, closed and locked, which over time can break the snib.

Replacement snibs can be purchased from our Jason Windows Spare Parts Shop or contact our friendly service team to help troubleshoot any problems you may experience with your Jason products at home.