A smart lock is not a new lock cut into your door. It is a motor and a keypad taking over the deadbolt holes that are already there. The cross bore, the edge bore, and the strike in the frame all stay put, which is why the swap reverses cleanly if you move or change your mind. If you have not picked a model yet, the fit checks in our guide to what to check before buying a smart lock come first — thickness, backset, and signal at the door decide which locks are even candidates. This page assumes the box is open and the lock fits.
Close the door. Turn the existing thumb turn slowly, without pushing or pulling the door with your other hand. The bolt should glide into the frame and seat fully with light finger pressure. If you have to lean on the door, lift it by the knob, or fight the last quarter inch, stop and fix that now: shift the strike plate a fraction, or file its opening slightly wider, until the bolt throws clean on its own.
This five-minute check decides whether the install succeeds. Your hand quietly compensates for a misaligned door every day; a small motor cannot. A lock on a binding bolt will strain, chew through batteries in weeks instead of months, and sometimes stop halfway while showing "locked" in the app. Alignment first, electronics second.
Tape the outside, remove the inside. Tape the exterior key cylinder or keypad to the outside face of the door so it cannot fall when its screws come out. Inside, remove the two screws from the thumb-turn assembly and lift it off. The old bolt stays in the door edge for the moment, held by the outside half.
Remove the old bolt. Take out the two screws on the door edge and slide the old deadbolt out. If your new lock reuses the existing bolt — retrofit models that sit over the inside hardware do — skip to step 4. For a full replacement, this is the whole teardown: door hardware off in about five minutes, nothing cut, nothing drilled.
Set the new bolt and check the backset. Most new bolts adjust between the two standard backsets, 2-3/8 and 2-3/4 inches — twist or slide the bolt body to match the old one you just removed. Slide it into the edge bore, drive its two screws, and turn it by hand a few times. Smooth and full travel, same as the check you opened with.
Mount the outside keypad, route the cable. Set the exterior keypad on the door, feeding its cable through the cross bore under or over the bolt, exactly as the maker's diagram shows — pinched cables are the number two cause of dead-on-arrival installs. Tape holds the keypad in place while you move inside.
Fit the mounting plate and the interior assembly. Screw the interior mounting plate to the door through the bore, snug but not cranked down — an over-tight plate can bind the bolt. Connect the cable to the interior unit with the connector seated fully, tuck the slack into the cavity so nothing is pinched, then clip or screw the interior assembly onto the plate.
Power up and hand over the direction. Load the batteries. Most locks run a short self-test on first wake, sensing which way the bolt needs to travel — run it with the door open, as most manuals specify, so a wrong guess cannot jam the bolt into the frame. Then throw the bolt a few times from the thumb turn and the keypad to confirm smooth motion.
Test with the door closed, then set codes. Close the door and lock it from the keypad, the app, and the key. All three should seat the bolt fully with the same easy sound as the open-door test. Now pair the lock with the app, set your main code, and add a separate guest code rather than sharing yours — codes can be deleted individually later, your main one cannot be un-shared.
| Setting | Sensible default | Why |
|---|---|---|
| Auto-lock | On, 30–60 seconds | The door re-locks itself after entry; the feature most owners say changed their habits |
| One-touch locking | On | Hold a button or tap the keypad to lock on the way out — no code needed to secure the door |
| Wrong-code alerts / lockout | On | The lock pauses after repeated bad codes and tells your phone about it |
| Activity log | On | Shows which code opened the door and when — the quiet advantage over a plain key |
| Volume / voice prompts | Low or off | A lock that announces itself at full volume gets old by day two |
One more thing while the tools are out: check the gap around the closed door. A smart lock seals the bolt, not the weather seal, and a door that rattles in its frame usually needs the felt replaced — a cheap job covered in our guide to replacing door weatherstripping.
Renters sit in a sweet spot here: nothing is drilled, the original deadbolt drops back in at move-out, and the door is left exactly as found. Three cautions. First, get the landlord's written OK before swapping — some leases treat locks specifically, and a two-line email protects your deposit. Second, keep every old part, screws included, in one labeled bag. Third, models that keep the outside cylinder unchanged are the easiest to approve, since the door looks untouched from the hall. More no-drill hardening ideas live in our renter-friendly home security checklist.
The motor stops halfway. Alignment, almost every time. Reopen the door, throw the bolt by hand, and fix the bind at the strike before blaming the lock.
The keypad lights but nothing pairs. The cable is the usual suspect — reseat the connector between the keypad and the interior unit, and confirm no part of it is pinched under the mounting plate.
The app shows the wrong state. The door sensor or the handing calibration is off. Rerun the setup routine with the door in the position the manual specifies, and mount the magnet sensor flush if your model uses one.
Thirty minutes, one screwdriver, zero new holes — that is the honest shape of this job, provided the bolt threw smoothly before you started. Check alignment, swap the hardware in order, test open and closed, then set a main code and a guest code and switch auto-lock on. The lock does the remembering from there.
About 30 minutes for a standard deadbolt swap, including setup in the app. Add ten minutes if the strike plate needs adjusting for alignment. Retrofit models that mount over the existing inside hardware are faster still — often 10–15 minutes, since the bolt and cylinder never come out.
No, on a standard door. Smart locks are built around the standard 2-1/8-inch cross bore and the two common backsets, so they reuse the holes your deadbolt already occupies. Drilling only enters the picture on doors with no deadbolt at all, which is a different and larger job.
Most full-replacement models keep a physical key cylinder on the outside, and the key still works when batteries die or the electronics glitch. Keep a key where you can reach it — a lockbox or a trusted neighbor — rather than relying on the keypad alone.
The lock warns you first — repeated low-battery alerts in the app and at the keypad, usually weeks ahead. If you ignore them to zero, most models offer an emergency option: a physical key, or holding a 9-volt battery to contacts under the keypad for one powered opening. Fresh AAs take two minutes to swap from inside.
Not well. A motor has far less force than your hand and cannot lean on the door to line the bolt up. If the bolt binds, fix the alignment first — shift the strike plate or widen its opening until the bolt throws with light finger pressure — then install. Skipping this is the top cause of jams and short battery life.