uPVC door - unable to deadlock from outside

[Al, Cambridge, UK]

I have a 15-year-old Anglian uPVC front door. To deadlock: I raise the outside handle to shoot the deadbolts top & bottom, then turn the lock (EuroLock) to lock them. Except today - lifting the outside handle doesn't shoot the deadbolts. I removed the handles and found that the mechanism engaged by the outside handle turns freely without acting on anything; the inside handle is still able to move the deadbolts and to retract the night- latch as normal. To get off to work, I have bodged the square-section bar on the outside handle to turn both inside & outside mechanisms so I can deadlock the door and open it again (I hope), but that leaves the outside handle also able to open the night-latch. So something has definitely gone wrong inside the door, so I'll have to dismantle it. I wonder if anybody can tell me what to expect when I take it apart? Thanks in advance for any help, Al

[John]

Has the square hole become rounded and is no longer engaging the shaft?

[Al, Cambridge, UK]

[e-mail]...

Hide quoted text -

Thanks for the suggestion, John. No, the hole was still square but the whole plate was able to turn freely without engaging with the rest of the lock mechanism. But the semi-good news is "was": I took the handles off last night and found that by undoing yesterday morning's bodge the door was now working again - the plate with the square hole now engages with the deadbolt mechanism again. So I'm sorted for the moment, but I'm not confident that it won't go wrong again so I've made sure we have emergency access to a *back* door key as well. Thanks again for the help. Al