UPVC gearbox type?

[D1l1th1um]

Hi people,

My door is starting to become very difficult to unlock. I changed the barrel out and it's still doing it. So, I guess I'm looking at replacing the gearbox next.
The handle works fine (pushing down) when the door is unlocked. To lock the door the small 'nipple' towards the top of the gearbox needs to be pushed in a mm or two, which allows me to rotate the handle upwards and engage the bolts. Once I turn the key, it sometimes unlocks straight away. Other times it could be upto 10 minutes of fiddling around, using a bit of force to turn the key, toget the door to unlock again. It does this if I just engage the bolts when the door is still open; so, it doesn't seem to be anything related to the door frame.
I tried looking for a similar gearbox, but couldn't find anything that had the 'nipple' on it.

Thanks,
Neil

 

[footprints]

Try this company I have found them good and helpful.
https://www.handlesandhinges.co.uk/multipoint-gearboxes-and-lock-cases/