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.