How to Fix a Double Front Door Latch

Open the door with the latch and check the position of the strike plate on the inside of the opposite door. Slowly close the latch door and make sure the latch bolt lines up with the strike plate. If the plate is too high or too low, remove the screws and shift it down or up slightly. The door could be pulled open, if it isn't locked, if the latch bolt is not engaging with the strike plate.

Loosen the screws holding the handle to the inside of the problem door. Pull the handle off to reveal the square rod and the inside of the latch mechanism. Pull the latch and handle off the outside of the door once the screws on the inside are out. Look for signs of wear on the square metal rod and test the action of the latch and handle. The square rod or square attachment on the inside of the mechanism should turn.

Spray a small amount of powdered graphite into the moving parts of the latch. Graphite is used by locksmiths and watch makers to lubricate delicate moving parts. Put the latch handle back into position and tighten the indoor handle back into place so the screws pull the latch handle tight. Test the mechanism a few times to work in the powder.

Take the latch apart again if the door continues not to work. You might need to install a new latch mechanism. Contact the manufacturer of your particular latch to find a suitable sized replacement. To remove the old latch mechanism, loosen the screws on the inside of the door and pry the old part out. When the new part arrives, insert it into the hole and replace the screws.