Toshiba Airconditioner WiFi troubles

This week I had three airconditioners installed - 2 Toshiba Kazumi's (RAS-B07J2KVSG (archived)) with optional WiFi module (archived) and a Haori (RAS-N4KVRG-E (archived)) which has the WiFi module built-in. Unfortunately I was on vacation during installation so the installers couldn't setup the AC's with my WiFi. Being reasonably capable of figuring this out myself I told them not to bother and I'd do it myself. I was aware of the (only) requirement of the WiFi modules for the AC's: they require a 2.4Ghz WiFi connection.

I'm pretty sure that what follows will go for a lot - if not all - of Toshiba's AC (consumer) models but I don't have access to any other models so I can't be sure. Your mileage may vary.

My house is, quite literally, littered with Amplifi devices; three AmpliFi HD mesh routers to be exact. Ofcourse I run dual-band WiFi (2.4Ghz and 5Ghz) and cranked all settings to max, up to 11. Needless to say, my WiFi is fast, reliable and has very decent range in and around the house. Looking in my Amplifi app over 60 WiFi devices are currently connected. Laptops, iPads, phones, a doorbell, Amazon Echo devices, lights, kitchen appliances, clocks, a bunch of temperature/humidity sensors, a P1 meter, and, hell, even my car is connected to my WiFi. All without a hitch. A lot of the sensors are ESP8266 and ESP32 devices - these also require a 2.4Ghz WiFi connection and work flawlessly.

Needless to say I didn't expect a lot of problems, maybe even none but who gets that lucky? So after returning from my vacation I set out to get my new AC's connected to WiFi and then set up in the app on my phone. What ensued was, however, hours and hours of trying, troubleshooting, rebooting the WiFi routers etc. etc. Creating separate SSID's for the 2.4 and 5 Ghz bands, disabling the 5Ghz band altogether, trying SSID's with just letters and numbers (my default SSID has a dot in it), short-simple passwords (some devices can't handle "special characters" like an @ or % or whatever)... nothing worked. I finally got tired of it and dug up a Linksys WAP54G with DD-WRT on it that hadn't seen the light of day since Mozes split the red sea. I configured it with my SSID, set my WPA2-PSK password and... sure enough, the first AC unit (one of the Kazumi's) connected. A little while later all three units were connected and talking to my WAP54G happily.

So, yay, it worked! However, the situation was far from ideal. I had the WAP54G doing it's 2.4Ghz chattering but my Amplifi's were doing the same. On the same SSID nonetheless. The WAP54G is outdated and years past it's End Of Life date and I didn't want it interfering with the rest of my (2.4Ghz band) WiFi. So now that I had seen the proof in the pudding, I set out to find out what the differences were between the WAP54G WiFi and the Amplifi WiFi signals. I tried to toggle a few settings on the Amplifi but none helped. Ofcourse. So next thing was to go about it methodologically. I unchecked all checkboxes and then checked half, applied the settings and then checked if the AC would connect. If it did, then those settings didn't cause the problem and I could check some more checkboxes. If it didn't then, well, one of the last checked checkboxes was the cause. I did this about... meh... three or four rounds and by then I had it narrowed down to 1 single checkbox:

802.11r - Fast BSS Transition
The culprit: 802.11r - Fast BSS Transition

This tiny little mo... checkbox was the root cause of the Toshiba AC's not connecting to my WiFi. Disable the checkbox: everything works fine and dandy. Check this checkbox: AC's appear to have bananas stuck in their ears. Uncheck: all's well. Check: bananas.

So, in my situation, I was able to perfectly reproduce the issue and the fix workaround for it. If you're running into the same issue: look for this setting or something named similarly. For the Amplifi device specifically: use a webbrowser to connect to the Amplifi's internal IP address, login and look for the option there. I am not aware of a way to (un)check this option in the Amplifi app. This option may not be available on your WiFi router or AP or, if it is, it may not be the solution for you. But I think it's worth a shot - hence why I document such things. Because I'm demented as a doorstop and can't remember what I changed 7 years from now when things stop working suddenly and because other people may also profit from my endeavours. I hope this works for you too!

Also, note: the second I got my AC's to connect for the first time (which was still on the WAP54G device), the first thing I did was update the WiFi Adapter. I updated the Haori from 1.5.<something> if I recall correctly to 1.7.01 which is the current latest version according to the app. The Kazumi's WiFi modules were updated from 3.0.<something> to 3.2.01. Turns out this DIDN'T help in the end but the first thing you want to do is make sure you're running the latest versions when troubleshooting an issue like this.


So now everything is documented, all I have left to do is notify Toshiba about this issue, point them to this blogpost and sit back and wait for a buttload of money for troubleshooting this issue and pointing them in the direction of a possible fix 😇

Also: I'm not quite sure how much this "802.11r Fast BSS Transition" affects anything except for the obvious it's stating - I don't know how much "slower" my "BSS Transitions" will be from now on. Time will have to tell. And, with some luck, Toshiba provides a fix so I can check this checkbox again and get my fast(er) BSS transitions back.

Update 2022-03-25: Toshiba has fixed the issue!

Today I received the following e-mail:
Dear Rob,

I would like to notify you about at this time we have released a new wireless adapter firmware version that will support IEEE 802.11r or Mesh Wi-Fi technology.

Wireless adapter modelCurrent firmware
New firmware
Type A:
RB-N101S-G, RB-N102S-G,
RB-N103S-G, RB-N104S-G
Type B:
RB-N105S-G, RB-N106S-G
Built-in adapter1.
Type C:
ESTIA Wireless adapter

After you've updated the firmware on your wireless adapter to the latest versions, then you can re-configure your router to support 802.11r.
Note: Wi-Fi Adapter firmware will revert back to Factory default firmware if the firmware update procedure is failed by an internet issue or AC power is lost during upgrade.
If you discover this, please disable 802.11r before pairing and updating your AC and make sure about firmware version is the latest version before re-enabling 802.11r again.

Thank you for your valuable advice. We would appreciate it if you could support us in sharing this information with other people in your country.

Anyway, if you have found any problem please do not hesitate to contact me.

Best Regards,
IoT Solution
Toshiba Carrier (Thailand) Co., Ltd.
So Toshiba actually got my message and looked into it and fixed the issue! Thank you Toshiba, that's some amazing service!


  1. Thank you so much for sharing this. I’ve almost gave up and then found this and now my AC is connected.

  2. Thank you! I've been strugling the same way as you describe until I've found your article. My setup was Deco X20 mesh routers and AC Wifi built-in adapters with version 1.8. After deactivating Fast beam and Fast roaming, I was able to connect my AC units. Immediately after connecting, Toshiba application suggested to update firmware to version 2.0. Both AC units and mesh now works.

  3. I went through a similar ordeal with the optional Wifi module of type A. In the end I had to downgrade the WPA mode from the standard WPA2-PSK/WPA3-SAE to only WPA2-PSK in order to have the Wifi-module connect. Hopefully this can help someone else in the same situation.

  4. No WPA3 support in year 2023 even with the latest firmware?

    1. What's stopping you from contacting Toshiba and asking them nicely?

  5. Rob, Thanks so much. I have been fighting this for months (using Ubiquiti UniFi network). BSS fixed it and now updating firmwares. Happy New Year from Prague. ❤️