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Smart locks for thick doors
Updated
If your door is thicker than 1-3/4 inches, pick a lock whose listing names your size, or buy the maker's thick door kit. Of our picks, the Yale Assure Lock 2 lists doors up to 2-1/4 inches, and the eufy C220 lists up to 55 mm, about 2.17 inches. The Schlage Encode needs a thick door kit above 1-3/4 inches.
Measure it right
Open the door and measure the edge, face to face, near the lock. Do not measure at the trim or a raised panel. Write it in inches to the nearest sixteenth. Then use the fit checker.
What each source says
- Schlage Encode, listing1.38 to 1.75 in
- Schlage Encode with thick door kit1.88 to 2.5 in
- Yale Assure Lock 2, Amazon listing1.75 to 2.25 in
- Yale Assure Lock 2, Yale support page1.38 to 2.25 in
- eufy C220, listing1.38 to 2.17 in
- Aqara U100, maker FAQ1.38 to 2.17 in
| Lock | Door thickness | Where we read it |
|---|---|---|
| Schlage Encode | 1-3/8 to 1-3/4 inches | Amazon listing |
| Schlage Encode with thick door kit | 1-7/8 to 2-1/2 inches | Schlage support page |
| Yale Assure Lock 2 Wi-Fi | 1-3/4 to 2-1/4 inches | Amazon listing |
| Yale Assure Lock 2 family | 1-3/8 to 2-1/4 inches | Yale support page |
| eufy C220 | 35 to 55 mm, about 1.38 to 2.17 inches | Amazon listing |
| Aqara U100 | 1-3/8 to 2-11/64 inches | Maker FAQ on the Amazon listing |
Two things stand out. First, Schlage's page says the Encode thick door kit covers 1-7/8 to 2-1/2 inches, while the listing covers up to 1-3/4. A door between those two numbers is not named by either, so ask Schlage. Second, Yale's support page gives a wider range than the Amazon listing. When sources disagree, ask the maker and keep their answer in writing.
Picks for a thick door
- Yale Assure Lock 2 Wi-Fi: up to 2-1/4 inches on the listing, and it works with Apple HomeKit. Caveat: owners report short battery life.
- eufy C220: fingerprint and keypad, with a wide 35 to 55 mm range on the listing. Caveat: not for Apple Home or Matter.
- Aqara U100: up to 2-11/64 inches in the maker's FAQ, with Apple Home Key. Caveat: needs a hub for remote control.
Thick doors bring other checks
- Longer bolts and screws come in the kit or the box. Do not force short screws.
- Thick doors are often heavy. Make sure the bolt still slides freely with the door closed. See the free throw check.
- Check the backset and hole size too. A thick door can still have an odd hole.
Compare all seven on our shortlist. Fit ranges change between versions, so confirm on the listing and in the manual.