I purchased four Aqara U100 smart locks. One of them works perfectly, but the other three are completely unusable, all showing the exact same behavior:
The keypad won’t accept input. Every button press just produces what I’ll call a startup/error beep.
To clarify: this isn’t the normal input tone. On my working lock, when I type a passcode (during setup or daily use), each digit makes a distinct confirmation sound. On these three faulty locks, I only ever hear the flat “startup” beep.
It feels like the locks are stuck in a startup phase. Best analogy: on Windows XP, if you mash the keyboard before the OS finishes booting, you just get an error chime.
Setup / pairing behavior:
When I press the set button on the back, the app provides me a pairing code, so the lock is clearly being detected and trying to transition into setup.
But since the keypad is stuck in the startup beep mode, I can’t actually input the pairing code. Each digit just throws the same beep, and nothing happens after I finish entering it.
On the working lock, setup is different: as soon as the last digit is entered, it confirms automatically — no need to press Enter.
To be clear: on these three locks, pairing has never succeeded even once. They’ve never functioned properly out of the box.
Other differences vs. the working lock:
No voice prompts at all on the faulty units (the working one announces clearly during setup).
The Enter/lock button does nothing.
They remain in this input-blocked loop.
What I’ve tried:
Replaced batteries several times with different brands (standard alkaline and even different chemistries).
Tried powering via USB-C with a high-power portable charger instead of batteries, in case it was a power issue — same result.
Removed/reinserted batteries to force a reboot.
Installed/uninstalled the locks multiple times, making sure the connector was properly seated.
Swapped parts between locks: I even took the front keypad face of the working lock and paired it with the back of a faulty lock — it worked fine. But the front faces of the faulty ones don’t work, no matter which back I use.
→ This proves the issue lies specifically in the front-facing keypad modules.
Batch / order details:
The one working lock came from its own separate Amazon order (bought first just to test).
The three faulty locks all came together in the same Amazon order.
Defects happen, but having all three from one order fail identically makes me wonder if I received a bad batch.
At the same time, it makes me second-guess myself: is there something I’m missing in the setup? But given that I’ve swapped parts and troubleshot extensively, it really seems like a defect.
Questions for Aqara / community:
Is this a known problem affecting certain U100 production batches?
Is there any firmware fix or method to get the locks out of this “startup beep” state?
Holding the reset button seems to achieve nothing, is there a different reset method other than the 3 second hold?
If this is hardware-related, what is the correct path to replacement?
For now I’m stuck using the mechanical key on those three, but I’d love to get them working like the first one.
It sounds like you’re dealing with a frustrating situation with your Aqara U100 smart locks. From what you’ve described, it seems like the issue with the three faulty locks might indeed be related to the front-facing keypad modules, especially since swapping these parts with a working one resolved the problem temporarily.
To address your questions:
Known Problem with Production Batches: While the reference information I have does not specifically mention issues with certain production batches of U100 locks, it’s possible that a batch defect could be the culprit given that all three faulty locks came from the same order.
Firmware Fix or Method to Resolve “Startup Beep” State: Unfortunately, there isn’t a specific firmware update mentioned in the reference data for this particular issue. However, ensuring that your Aqara app and the firmware for the locks are up-to-date is always a good step. You might want to try reinstalling the locks in different setups as you’ve done, but the persistent issue suggests a hardware problem.
Alternative Reset Methods: The standard reset procedure involves holding the reset button under the battery compartment for over 3 seconds, which you’ve already tried. If this doesn’t work, it’s possible that the locks may require more advanced troubleshooting or servicing.
Hardware-Related Path to Replacement: Since this seems to be a hardware issue, your best bet would be to contact Aqara’s customer service for further assistance, especially if these units are under warranty. Please contact the Customer Service Team via the Aqara Home App (Profile > Help & Feedback > Customer Service) or by scanning the QR code below. If you do not have an Aqara Home account, you can create a ticket here for further support.
I hope this helps, and I encourage you to keep the community posted on your progress. Perhaps other users might have faced similar issues and can offer additional insights. Good luck, and I hope your locks get sorted out soon!
Just wanted to close the loop here. The issue was that the locks were on different software versions, and during installation the fronts and backs got mixed. That mismatch caused the keypad to stay stuck in the startup beep loop.
The solution is simple: keep the original front and back together, or update all locks to the same software version so mixing isn’t a problem.
Most people probably won’t ever run into this since it’s uncommon to buy multiple locks with different versions and then accidentally swap parts, but I’m sharing in case it helps someone in the future.
Thanks to everyone who replied and offered suggestions!
