A customer in Ashford called because the front door could no longer be opened from inside, although the key would still open it from outside.
As soon as I removed the nightlatch backbox, the failure was obvious.
The pin that should have connected the internal lever to the latch had sheared off and was left loose inside the backbox. That meant the outside key could still operate the lock, but the internal lever no longer had anything solid to act on.
These are good locks in terms of security and functionality, but when this particular internal part fails there is very little useful repair to carry out inside the existing unit.
Fortunately, the customer could still open the door with the key from outside. If the lock had failed completely with the door shut, gaining access would have been a much more involved job.
I replaced the complete nightlatch system and tested both the internal and external operation.
The front door was then working normally again from both sides.
