Velux window - installed 1989(?) - hasn't ever locked. Jammed headlock?

[Autechre]

The part no. is GGL-4.

The central sliders won't move at all, as if jammed. It's been like this since the installation, so I don't think a lack of lubrication is the problem, though I've given a hefty amount to both, left for 24 hrs and tried again, but no joy.

The locking pins move a bit and spring back into place and locate where they should on the striking plates:

What would people advise?

Cheers.

 

[Autechre]

I've discovered that I can push the two locking pegs down to their 'locked' position by hand, which moves the centre slider up, but I can't move the slider on its own when trying to push it up with the Velux handle. Even after removing one of the locks and trying with substantial brute force to push the slider up or pull it up, it won't budge. The mechanism needs too much force.

I can't see how anyone could realistically lock the window - the wooden handle would break before the lock moved.

Does this look fine?

I can't help thinking that this is a duff lock, wrongly manufactured, but still off-loaded onto the public. The huge force needed suggests to me that the wire is too thick.

I know this was installed a long time ago, but could this be a possibility?

 

[Abingdon Parts]

Did you ever solve this issue? I have a 1976 window and latch with the same issue (it won't latch), I've spoken to very helpful Velux, who deny any knowledge. My latch and strike plate look exactly like those in your, now very old, post. I'd love to know whether you found a solution.

 

[catlad]

You can purchase a bottom handle from velux to lock the window if you are having problems with the top handle.