While raising three young kids, our house remains in a steady state of chaos, with several doors to the house being opened about 500 times a day (but closed back only half the time). Keys get lost, and messages get mixed up, and in all this confusion, we've locked ourselves out of the house a few times. I decided to put an end to that by installing an electronic keypad door latch. I can still use an old-fashioned metal key as a backup, but plan to rely mostly on a personalized numeric code which I simply punch into the latch's keypad to unlock the door. With no metal key to keep up with, nobody will be stuck outside until someone with a key shows up to save the day.
Good news for DIY'ers who want to replace an existing deadbolt: This is a very simple upgrade that doesn't require any special tools or wiring.
First step is to unscrew the mounting bolts of the old deadbolt so you can separate the lock assembly in two halves, which you can them remove from each side of the door. With the lock assembly out of the way, unscrew the the two screws mounting the deadbolt and pull the bolt assembly out from the edge of the door. With all the hardware gone, you're ready to add the new keypad lock.
Begin by installing the new bolt assembly, which might slip right into the old hole with no adjustment. Otherwise, it might be necessary to square up the mortise in the door's edge using a wood chisel so the face-plate fits flush with the wood surface. The Hickory Hardware product shown also includes an adjustment switch on the bolt that can fit latch bore holes with either a 2-3/8-in. or 2-3/4-in. back-set.
The locking assembly installs similar to the ones you removed, but the interior side of the door utilizes an extra piece--a locking plate through which the two mounting bolts pass and thread into the the back of the exterior lock assembly. The exterior side of the lock includes the keypad, keyhole, adapter collar, and rubber backing, all of which you pre-assemble and install as a single piece.
When installing the lock assembly, it's important to thread the wire of the keypad under the door latch then through the wire passage on the interior mounting plate. It's also important to insert the flat arm of the exterior lock assembly through the latch while the deadbolt is in the unlocked position. meaning the slot should be oriented left to right, not up and down.
Next, you'll need to connect the wire to the terminal on the back of the interior lock assembly. Push in the plastic connector until it fits snugly. Then, place the assembly over the metal mounting plate and fasten in place with the included metal screws. To activate the keypad door latch, add the batteries--four AAs, in this case.
Follow the manufacturer's instructions for setting your personalized code using the keypad. The last step is to snap on the interior battery cover to give the door a sleek, finished appearance.
That's all there is to it. And don't worry about dead batteries causing the lock to fail. A visual indicator flashes on the lock anytime the batteries get low, so you'll have plenty of notice to install new ones.