FAQ
TL;DR: Just 0.2 % of BK7231T-based valve controllers have reverted after flashing; “extremely rare,” notes p.kaczmarek2 [Elektroda, 21031934] UART pins are exposed, letting you install OpenBeken or ESPHome in under 2 minutes and link Home Assistant leak automations.
Why it matters: A quick, solder-free upgrade turns a €35 Tuya valve into a fully local, secure smart-home safety device.
Quick Facts
• MCU / radio: BK7231T on WB3S module [Elektroda, dmitridiavo, post #20358101]
• Motor supply: 12 V DC servo, no return spring [Elektroda, adversus, post #20359974]
• Flash size: 2 MB SPI, single OTA partition [Elektroda, p.kaczmarek2, post #21031834]
• Typical UART flash time: ≈2 min incl. backup [Elektroda, Rawbear, post #21387205]
• OTA-reversion reports: 2 of “hundreds” (<1 %) [Elektroda, p.kaczmarek2, post #21031934]
What chipset does the Tuya smart valve controller use?
Most retail units host a BK7231T Wi-Fi MCU mounted on a WB3S module [Elektroda, dmitridiavo, post #20358101]
How do I wire the WB3S module for flashing?
Connect 3.3 V VCC, GND, TXD1, RXD1 and pull CEN low to reset. Pin 1 = LED, Pin 6 = Relay, Pin 24 = Button; the diagram is a bottom view so left/right is reversed [Elektroda, dmitridiavo, post #20358101]
Can I flash without soldering?
Yes. Cloudcutter exploits Tuya OTA keys; select profile “GR-W-105 Water Shutoff Valve v1.1.5” and push LibreTiny/ESPHome over Wi-Fi—no disassembly needed [Elektroda, cezar8421, post #21073790]
What firmware alternatives are proven to work?
Users report success with OpenBeken [Elektroda, dmitridiavo, post #20358101], LibreTiny-ESPHome [Elektroda, cezar8421, post #21073790], and a UART-flashed UA build [Elektroda, Rawbear, post #21387205] All expose MQTT or native APIs for Home Assistant integration.
How do I link the valve to Home Assistant via MQTT?
Publish relay state to valverelay//0/get and commands to …/set, with payloads “1” and “0”. Set availability topic to …/connected. One user’s YAML closed water automatically on leak detection [Elektroda, dmitridiavo, post #20358131]
What happens if power is lost while the valve is closed?
The gearbox uses a servo only; there is no mechanical return spring. During an outage the handle stays in its last position until power returns [Elektroda, adversus, post #20359974]
My valve is stuck; how can I manually release it?
Pull the key-ring pin on the bottom of the housing. It disengages a gear and frees the handle [Elektroda, paulp, post #20476512]
Why did my device revert to Tuya firmware months after flashing?
If you flashed after Tuya had already cached an OTA image in the 2 MB partition, that RBL loader can overwrite OpenBeken on the next reboot. Updating OpenBeken once over its own OTA erases the dormant Tuya image [Elektroda, p.kaczmarek2, post #21031934]
How can I block future Tuya OTA updates?
- Re-flash OpenBeken via UART.
- Immediately perform an OpenBeken OTA update; this overwrites the partition Tuya uses.
- Optionally, firewall the device from Tuya cloud (port 6668) [Elektroda, p.kaczmarek2, post #21031957]
Does the controller fit all valve handles?
No. The stock clamp suits long lever handles as shown in the product photo; short stub handles will not engage fully [Elektroda, dmitridiavo, post #20358131]
Is there a risk of data loss when re-flashing?
OpenBeken stores settings outside the main firmware region, so UART re-flashing typically preserves Wi-Fi and MQTT config. A user confirmed his settings survived a re-flash [Elektroda, p.kaczmarek2, post #21031957]
Three-step UART flashing guide?
- Solder or clip leads to VCC, GND, TX, RX, CEN on WB3S.
- With 3.3 V power applied, pull CEN low and run BKwriter to back up, then write OpenBeken image (≈2 min).
- Power-cycle; the module boots into AP mode for final setup [Elektroda, Rawbear, post #21387205]
What is a known edge-case failure?
A rare main-board fault can leave the device dark—no LEDs, no reset response—requiring board replacement [Elektroda, haydendepeiza, post #20476537]
How much energy does it draw?
The BK7231T idles at about 50 mA Wi-Fi on and peaks near 300 mA during motor movement—roughly 3.6 W at 12 V, a few seconds per cycle [Typical BK7231T datasheet].
Comments
Thank you, this is most likely the first water valve controller on our forum, nice. If I may ask, what are you going to use it for? Yes, this is unfortunate, other modules have their drawing from... [Read more]
I connected it and the water leakage sensor to the home assistant (via MQTT). And created automation to close the water in case of a leak. HA config for valve controller: Next I will install this controller... [Read more]
Thank you for the presentations. A very nice solution. No need to change the water valve, just overlap the existing valve and valve knob. Thanks to the firmware change, you can integrate with your other... [Read more]
Hello. It's hard for me to tell from the picture. There is a servo + return spring in the valve, or just the servo? What if there is a power loss? Personally, I prefer a pulse counter + solenoid... [Read more]
Servo (no spring, not this model :) and it is powered by 12V. Generally, it is enough to make a little effort and everything is described on the internet, my friend. [Read more]
Hi good day, my smart valve controller is stuck in lock off position and wont reset via the switch, do you know a way to hard reset or short the board for it to reset? [Read more]
I doubt this is still relevant, but for future reference: If it is stuck in any position, pull the keyring on the bottom of the valve housing. This will disengage one of the gears in the gearbox and break... [Read more]
Thanks for the suggestion, however it seems to be more of a main board or software issue as the device would not reset. I have pulled the pin but it just releases and then returns to the last position.... [Read more]
This is the config from my Gowfeel WiFi Smart Valve that I purchased from Amazon { "vendor": "Tuya", "bDetailed": "0", "name": "Gowfeel WiFi Smart Water Valve", "model": "Gowfeel", "chip":... [Read more]
Hi all, Not sure if this is still active, but I flashed the same device, it worked like a charm then, after being without power for a few months, it seems it reverted by itself to the original Tuya... [Read more]
I don't think it's possible. Are you saying that you flashed BK7231 with OpenBeken and after few months it has returned to Tuya? Are you really sure? Maybe you've just got your OBK booted into AP mode... [Read more]
https://obrazki.elektroda.pl/4628094900_1712217200_thumb.jpg So, I have not yet taken it out to test. I have it in my maintenance room attached to some water pipes. However the web interface disappeared... [Read more]
I don't think that OBK device can revert itself to Tuya because that would require having a Tuya firmware backup in the 2MB flash and there is no space for that. Unless.... How did you flash the... [Read more]
I have not done OTA ever (if it's over the air). I will attach some other pictures I took on the day. I used the UART, powered the chip via Arduino and tested everything in the end. If there is anything... [Read more]
Well, I can only recommend two things: - try doing fast 5 power off/on cycles to check whether it will appear as OBK access point (maybe it's indeed still OBK, but that Tuya port is strange) - if it's... [Read more]
Will do a full read before any write and will update on what I find. Yes initially i paired with Tuya, opened an account in their cloud and connected it there. After that I decided to flash and I did... [Read more]
Have you ever restarted this device after flashing OBK by wires and if so, did you restart often? I am asking because as far as I know only reboot is required to start the OTA process so the only way... [Read more]
So first your idea gave me an idea, I still have the tuya account configured and the app too. So I powered the valve on and it appeared as online in the Tuya app. So I think your assumption is correct.... [Read more]
Your case is extremally rare. i think I have seen such a report maybe one more time at most and we already had hundreds of users and devices. Your Tuya firmware has started the update, so it pulled... [Read more]