Door won’t latch unless locked

[Cullyvan]

My external door has been getting worse and worse. The handle is slack and hangs down instead of remaining horizontal.
The door latches by putting the handle up when it is shut and some levers slat out from the door and into the frame. But because the handle returns to the down position it doesn’t stay latched unless you lock it.
It used to work okay but over the years has gotten more and more slack. Does anyone know what the problem might be and how to fix it?
Thank you

 

[theknobs]

The handle is held up by a return spring within the mechanism. This is obviously weakened with time. I doubt if it is possible to get a replacement for the spring, you will probably need a complete lock. There are several makes of these and you will want an identical replacement so that it is a straight swap into the space in your door frame.

 

[Mrreliableone]

It's almost certain to be the door lock gearbox case that's just worn out, which they do. In order to buy the correct one, it's necessary to remove the old one first so that you may buy an identical one. I hope this helps.