When it comes to HomeKit devices, our own Zac Hall is the resident expert around these parts, but I’m doing my best to come up to speed with the plethora of options available. I recently took my first stab at installing a smart lock, the 3rd gen August Smart Lock, only to later find out that it wasn’t HomeKit compatible. It’s primarily my fault, because I wasn’t diligent enough with my research, but August, with its somewhat confusing nomenclature should take a portion of the blame as well.

Needless to say, I wasn’t keen on the idea of having a smart lock installed without HomeKit support. That would mean that I couldn’t unlock my door with Siri commands, couldn’t use the Home app to control the lock, and couldn’t use HomeKit automation to trigger other HomeKit-enabled devices. In other words, a smart lock without HomeKit support is just not something that appeals to me.

That’s not to say that the third-generation August Smart Lock is a bad product, because that certainly isn’t the case. It’s actually a decent product that’s inexpensive and easy to install. It’s just not for those who are knee-deep in the Apple/HomeKit ecosystem.

I reached out to Yale Real Living to inquire about reviewing its Assure Lock SL, which recently landed support for HomeKit via its iM1 network module. What I discovered was a modestly-featured smart lock with a fair amount of advanced controls. In fact, I’m strongly considering the purchase of another one.


  • ANSI Grade 2 lock
  • HomeKit compatible via iM1 network module
  • Touchscreen keypad
  • One-touch locking
  • Motorized deadbolt
  • Voice assistance
  • 9V battery back-up
  • Advanced settings
  • Available in polished brass, oil rubbed bronze and satin nickel
  • Includes 4 AAA batteries and all necessary installation hardware
  • Supports English, Spanish and French lunges

Door fitting information

  • Requires that you replace entire lock, so not ideal for apartments
  • Fits on standard doors 1-2/4-inch to 2-1/4-inch thick
  • Requires a face bore hole of 2-1/8-inch
  • Backset of 2-3/8-inch or 2-3/4-inch
  • Edge bore hole of 1-inch


The Yale Assure Lock SL comes with almost everything you’ll need to install the smart lock on your door. You’ll need to provide a screwdriver, and may need other tools depending on your door, but for the most part it should be a straightforward affair.

Inside the box you’ll find the following:

  • Deadbolt
  • Strike plate
  • Exterior door panel
  • Interior panel
  • Mounting plate
  • iM1 network module
  • Screws
  • Batteries

Step 1: Remove your existing lock

Step 2: Install the deadbolt

Step 3: Install the strike plate. I omitted the strike plate installation, and kept the exiting plate, because it wouldn’t be a 1:1 swap. This is more than likely option in your case as well.

Step 4: Install the exterior touchscreen keypad.

Because the door hole wasn’t big enough, I used a drill to bore out a larger hole. There are probably more logical, safer ways to do this, but this was the only tool I had access to.

Once the hole was large enough, the exterior keypad fit nicely.

Step 5: Install the interior mount plate. You’ll need to route the connecting wire through the plate where designated. Use one of the sets of included screws to secure the interior plate to the exterior keypad.

Step 6: Connect the cable from the exterior keypad to the interior section via the 10-pin connector.

Step 7: Attach the interior lock mechanism to the mount using the three small included screws.

Step 8: Install the iM1 network module. Be sure to do this before inserting batteries.

Step 9: Install batteries

Step 10: Attach battery cover

Once the hardware installation is completed, you can install the Yale Secure app, configure the keypad, and set up HomeKit. As noted, it’s a very easy installation, as long as the door and door jam cooperates.

Hands-on impressions

First and foremost the Yale Assure Lock SL is relatively easy to install. Keep in mind, however, that it’s a full lock swap, meaning that it will replace both the interior and exterior knobs, along with your existing deadbolt. This may be a non-starter for renters, which should look at other HomeKit-enabled solutions, like the August Smart Lock Pro.

The Yale Assure Lock SL comes in one of three exterior finishes. These include the pricier polished brass, and oil rubbed bronze, along with the more price conscious satin nickel, which is the one I have. The finish is of a high quality, and the hardware itself feels weighty and well-built. The unit, although more svelte than past models, is still kind of bulky, lacking the type of modern fit and finish that some of the other smart locks possess. That said, this lock will probably look good well into the future, because it lacks the in-the-moment-design of some of its competitors.

It’s the little details that make me appreciate the Assure Lock SL, including an ANSI Grade 2 deadbolt with a tapered design that’s more likely to fit misaligned doors. There’s also an extremely handy 9V battery backup feature to help prevent lockouts due to dead batteries.

The Assure Lock SL, as you may have noticed, ditches physical keys completely, which means you’ll need to rely on a passcode, app control, or HomeKit control to use it. That can be both a plus and a minus in certain situations. It’s a plus from a security standpoint, because if there’s no physical key lock, there’s no key picking, lost spare key situations, etc. But it also means that you’ll need to have power to the unit in order to get inside, and while highly unlikely, electronics can fail. In fact, Yale recommends that there be additional points of entry because there is no mechanical override if things go south. Again, unlikely, especially with the 9V battery backup feature, but still possible.

Dead batteries? The 9V battery backup feature allows access

Even with a full on lock swap, I found the installation to be well-explained in the manual, making it easy to follow along. My install was a tad more complex because the hole for the exterior portion of the lock wasn’t large enough to fit through. A few minutes with a drill bit solved that problem, though.

Once everything is installed (watch our video above for a step-by-step install guide), it takes just a few minutes to configure the master passcode and enable the iM1 network module via the exterior touchscreen keypad. While the keypad lacks haptic feedback, the speakers emit an audible tone to help confirm proper keypad entry. The speakers will also speak instructions when it comes to using and configuring the Assure Lock SL.

HomeKit support is enabled by the iM1 module, which can be purchased separately if you already have the Assure Lock SL. HomeKit support works exactly like expected, allowing users to control the lock using the Home app, via Siri commands, or via automation.

Assure’s own Yale Secure app provides additional configuration options for settings like auto relock, one touch lock, wrong code entry limit, speaker volume, etc. Most, if not all of these settings can be configured manually via the touchscreen keypad menus, but that’s obviously a much slower undertaking. The app can also be used to establish extra passcodes, but there is no option to create auto-expiring passcodes, which is a bummer.

Activating the keypad for passcode entry requires the user to place a palm or back of the hand on the touch surface. Once the keypad lights up, the user simply types in the 4-8 digit code to unlock the door. Incorrect entries will, of course, keep the door locked, and users can set the desired threshold for incorrect entries and attempts via the app.

Users can set the number of attempts to as little as 3, and a shutdown threshold of as long as three minutes. This would slow down a potential intruder significantly, but I wish there were even lengthier shutdown options, or perhaps even an audible deterrent after so many wrong attempts. It would also be nice if you could receive some sort of notification after a number of incorrect attempts.


I’m very excited about my new smart lock, which may have something to do with never having used a HomeKit-enabled lock before. Once the newness wears off, I’m sure I won’t be as excited about it, but it does virtually everything I could ask of a smart lock at this juncture.

iM1 network module

There are some notable omissions, like auto expiring passcodes, but that’s something that will hopefully be added with a future firmware update. To be frank, the Assure Lock SL isn’t the prettiest lock out there, but it’s not an eyesore and features a high quality finish. Even though there are no keys, the keypad and 9v battery backup lend the necessary peace of mind that, in the event of a power outage or phone loss, I can still get back inside.


  • Easy-to-follow instructions
  • Works with HomeKit
  • No extra hubs required outside of Apple TV/iPad
  • Keyless design
  • Touchscreen keypad
  • Speaker with audible confirmation tones and directions
  • Privacy button
  • Relatively sleek design
  • 9V battery backup


  • Replaces both interior and exterior knobs
  • No auto-expiring passcodes
  • No logs for lock usage
  • Design lacking compared to others
  • Bronze and brash finishes are pricey
  • No keys may be too much for some users

If you rent, then you might be better served by a Smart Lock Pro from August, an outfit recently purchased by Yale’s parent company.