FAQ
TL;DR: The Sonoff SNZB‑04 is a Zigbee sensor that requires a Zigbee gateway/bridge for the eWeLink app; one user noted a 30 Mbps Wi‑Fi bottleneck and said, “devices network themselves but need a gateway.” [Elektroda, bubu1769, post #21689941]
Why it matters: This FAQ shows how to get your SNZB‑04 working fast, explains the "bridge" requirement, and helps you choose the right setup if you’re asking “which app do I use?” and “do I need extra hardware?”
Quick Facts
- Protocol: Zigbee; you must pair the sensor through a Zigbee gateway/bridge, then manage it in eWeLink. [Elektroda, bubu1769, post #21689655]
- A gateway links your local Zigbee mesh to the internet/app; the sensor cannot join Wi‑Fi directly. [Elektroda, bubu1769, post #21689527]
- Works locally: after setup, Zigbee devices continue to interact even if Wi‑Fi is down. [Elektroda, bubu1769, post #21689681]
- Battery-friendly: users move to Zigbee for low power use in door/window sensors. [Elektroda, JORGEN1970, post #21689908]
- Real‑world note: heavy Wi‑Fi smart devices caused only 30 Mbps until separated; Zigbee reduced congestion. [Elektroda, bubu1769, post #21689941]
Which app should I use to set up the Sonoff SNZB‑04 door sensor?
Use the eWeLink app, but only after adding a compatible Zigbee gateway/bridge to your eWeLink account. Then pair the SNZB‑04 through that bridge. [Elektroda, bubu1769, post #21689655]
Do I need to buy extra hardware, or can I pair the SNZB‑04 directly to my phone or Wi‑Fi?
You need a Zigbee gateway/bridge. The SNZB‑04 speaks Zigbee, not Wi‑Fi, so it cannot connect directly to your router or phone. [Elektroda, bubu1769, post #21689527]
What does “bridge” or “gateway” mean for Zigbee?
A Zigbee bridge is a hub that joins your Zigbee devices into a local mesh and provides the internet link for the eWeLink app. It is required for control and automation. [Elektroda, bubu1769, post #21689527]
How do I pair the SNZB‑04 in eWeLink?
- Add and connect a compatible Zigbee bridge inside eWeLink.
- Put the SNZB‑04 in pairing mode near the bridge.
- In eWeLink, choose Add Device via the bridge and complete pairing.
“Connect to the gateway first, then add Zigbee devices.” [Elektroda, bubu1769, post #21689655]
Will the sensor keep working if my home Wi‑Fi goes down?
Yes. After setup, Zigbee devices continue to interact locally through the bridge, even without Wi‑Fi. Cloud features pause, but automations can still run. [Elektroda, bubu1769, post #21689681]
Why pick Zigbee over pure Wi‑Fi sensors?
Zigbee forms its own mesh, reduces Wi‑Fi congestion, and suits battery devices. One user reported only 30 Mbps when Wi‑Fi smart gear crowded the network, prompting a shift to Zigbee. [Elektroda, bubu1769, post #21689941]
Does the SNZB‑04 work with eWeLink out of the box?
Yes, with a compatible Zigbee bridge. In eWeLink, add the bridge first; only then will the app discover the SNZB‑04 as a new device. [Elektroda, bubu1769, post #21689655]
I added the sensor in eWeLink but it doesn’t appear. What’s wrong?
You likely tried to add it without a Zigbee bridge. Add a supported bridge to eWeLink, then re‑pair the SNZB‑04 through the bridge. [Elektroda, bubu1769, post #21689655]
Is Zigbee really lower power for door sensors?
Yes. Users cite low energy use as a key benefit for contact sensors, which helps extend battery life. “This configuration can consume very little energy.” [Elektroda, JORGEN1970, post #21689908]
What exactly is Zigbee?
Zigbee is a wireless protocol for smart‑home devices that creates a self‑healing mesh. Devices talk locally, while a gateway links them to your app. [Elektroda, bubu1769, post #21689681]
Can I mix brands for the Zigbee bridge and sensor?
Yes, you can use other manufacturers’ Zigbee 3.0 bridges that work with eWeLink. Add the bridge in eWeLink, then pair the SNZB‑04. [Elektroda, bubu1769, post #21689655]
What’s the real benefit of the bridge beyond internet access?
The bridge keeps the Zigbee mesh running locally. Devices can still interact and trigger automations during internet outages or router issues. [Elektroda, bubu1769, post #21689681]
Any setup tips to avoid Wi‑Fi slowdowns with smart devices?
Move battery sensors and simple triggers to Zigbee. This offloads traffic from your main Wi‑Fi. A user saw a 30 Mbps cap before segmenting networks. [Elektroda, bubu1769, post #21689941]
I followed this guidance—did anyone confirm success?
Yes. The original poster returned to confirm that after buying a gateway, everything worked with the SNZB‑04. [Elektroda, JORGEN1970, post #21692101]
