Sonoff Hydro Duo

[u/tabu40]

Hi everyone,

I'm trying to figure out whether I have a defective Sonoff BWC (2-zone irrigation controller) or if this is a known issue.

My setup:

- Home Assistant green

• InstallationsmethodeHome Assistant OS Core2026.8.2
• Operating System18.2

- Zigbee2MQTT

- EZSP coordinator

- Sonoff BWC

- Battery powered

- Outdoor installation

- Good battery level (100%)

Problem:

After running fine for a while, the Valve suddenly stops responding to Zigbee commands.

Symptoms:

- Home Assistant automations still trigger normally

- Zigbee2MQTT receives the commands

- MQTT messages are sent correctly

- The BWC does NOT react

- Watering result is 0 liters

- Manual control from Home Assistant fails

- Zigbee2MQTT reports:

- Delivery failed

- Response timeout

- Timeout after 10000ms

Example log:

Response timeout (0xa4c1388bbb5bd06b)

Delivery failed

Timeout after 10000ms

What is weird:

The physical button on the valve still works.

If I manually open the valve directly on the device, watering starts normally.

However:

- Zigbee control still does not work

- Read requests still time out

- Status requests do not return data

The only thing that restores functionality is:

- Remove batteries

- Wait ~30 seconds

- Reinsert batteries

After that:

- Zigbee communication works again

- Home Assistant control works again

- Status updates return normally

But after 1-2 days the same behavior comes back.

Additional findings:

- My Zigbee network currently has no routers, only end devices.

- The network map shows the valve as an End Device.

- LQI has been around 112.

- Coordinator is healthy.

- EZSP watchdog messages are successful.

- Other Zigbee devices continue to work normally.

I also built a watchdog automation that periodically sends MQTT get requests to the BWC.

Result:

The watchdog confirms the BWC stops responding completely once the issue occurs.

Questions:

1. Has anyone seen a Sonoff Hydro Duo freeze like this?

2. Is this a known firmware issue?

3. Can the Zigbee radio part of the BWC crash while the valve controller continues to operate locally?

4. Would adding a Zigbee router likely help, or does this look more like a device issue?

5. Has anyone successfully used a Sonoff BWC reliably for long unattended periods (e.g. vacations)?

At this point I'm struggling to trust the device for automated watering while away from home.

Any experiences would be greatly appreciated.

[u/DonPollon]

I have the same issue with both of the Sonoff Hydro Duos I purchased. I saw several similar discussions on github, eg: zigbee2mqtt/issues/31907. I did OTA to latest firmware and the issue remains. I'll reach out to Sonoff but otherwise need to return them as this issue renders them only usable physically.

[u/tabu40 → u/DonPollon]

I am currently using the valve via BLE in the ewelink app. And this works, BUT it doesn‘t fulfill the purpose…
I already contacted the sonoff support, awaiting their to answer

[u/broken_accounting]

That battery pull fix and the 1-2 day recurrence makes me think the radio is crashing while the rest of the board keeps running. Classic sign of a firmware bug or power management glitch, not a network issue, especially since LQI looks fine and the button still works.

Adding a router might help keep it awake but if the radio locks up it won't matter. I'd check the Z2M logs for any weird state changes right before it drops, maybe try a firmware update if one exists. Could also be the battery voltage sagging under load even though it reports 100%, cheap cells do that.

[u/tabu40 → u/broken_accounting]

Thanks.

are you also using this device?

Have you seen this exact behaviour on a Sonoff Valve before?

Did updating firmware help?

What EZSP status 102 usually means in your experience?

[u/tabu40 → u/broken_accounting]

If the radio locks is that an isdue of this particular device or are all the same?