Fit a new night latch to your front door, swapping the cylinder, case and keep for a secure, smooth-closing lock.
NL-01Gather your tools and protect the areaLay a dust sheet under the door to catch screws and wood shavings. Check your new night latch kit has a cylinder, case, connecting bar, keep and screws. Have a pencil, screwdriver and a drill with wood bits ready in case you need to adjust any holes.
1 each · Night latch kit (cylinder, case, keep, screws) NL-02Check the new latch matches your doorMeasure the door thickness and compare it to the backset range printed on the box — most night latches suit doors 40mm to 55mm thick. Hold the new cylinder against the existing hole to see if it will cover the old one. If the new hole needs to be bigger, you'll enlarge it in the next steps rather than trying to force an ill-fitting lock in.
NL-03Remove the old keep from the frameUnscrew the keep (the metal staple the latch bolt clicks into) from the door frame. Keep the screws separate so you don't mix them up with the new set. Fill any screw holes that won't line up with the new keep using wood filler, and leave it to dry.
NL-04Remove the old latch case from insideUnscrew the two screws holding the latch case to the inside face of the door. Lift the case away from the connecting bar and set it aside. Don't remove the cylinder yet — the case coming off first stops the cylinder falling out and marking the paintwork.
NL-05Remove the old cylinder from outsideFrom outside the door, push the cylinder through the hole and pull it clear. Check the connecting bar comes away with it. Wipe around the hole to clear old dust or paint flakes so the new cylinder seats flush.
NL-06Fit the new cylinderPush the new cylinder through the hole from outside, keeping it level. If the hole is slightly too small, widen it a little at a time with a drill and sanding block rather than forcing the cylinder — a snug fit stops the lock rattling later.
1 each · Fine sandpaper or sanding block NL-07Connect the bar and fit the new caseFrom inside, slide the connecting bar through the back of the cylinder so it lines up with the latch case. Hold the case against the door and check the bar moves freely before screwing the case in place. Screw through the two fixing holes into the door — don't overtighten, as this can bind the mechanism.
NL-08Fit the new keepClose the door gently and mark where the latch bolt meets the frame with a pencil. Position the new keep over this mark and screw it into the frame. Check the latch bolt slides smoothly into the keep as the door closes, without needing to be slammed.
NL-09Test and adjustTest the lock from both sides: turning the key outside, and using the snib or knob inside. If the latch feels stiff or doesn't fully engage, loosen the case screws slightly and realign the connecting bar, then retighten. Check the door still closes flush and the latch doesn't rattle.
NL-10Tidy up and do a final security checkSweep up any shavings or dust and remove the dust sheet. Give the door a final open-and-close test, including locking it from outside with the key. Keep the old latch and keys somewhere safe until you're sure the new one works reliably, then dispose of them.
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