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Setup & Wi-Fi Shelly troubleshooting

Shelly BLU device not found, or stopped reporting

A BLU sensor or button won't show up when you add it, or it was working and went quiet. Check it's awake, that a Shelly near it is acting as its gateway, and how you added it.

Checked

  • Gen4

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What are you seeing?

Pick the closest match and we'll point you to the fix most likely to sort it.

Go to the fix

Why it happens

Shelly BLU devices run on a coin cell and talk over Bluetooth, so they have no Wi-Fi of their own. A mains-powered Shelly or a BLU Gateway nearby listens for them and passes their readings on.

To save the battery, a BLU device sleeps and only sends when something happens. Most "not found" problems are the scan missing it while it sleeps, or no gateway being close enough to hear it.

Quick checks first

Run these checks before moving on to the fixes.

Checklist 0 of 3 checked
Check you have a gateway

You need a mains-powered Shelly (Plus, Gen3, Gen4 or Pro) or a BLU Gateway within range. A BLU device has no Wi-Fi of its own.

Check the distance

Shelly gives a range of up to 10 m indoors and recommends a gateway in every room.

Press the button once

Its light should flash, or on the BLU Motion, flash red when you move in front of it. No flash at all points to the battery.

Fixes, most likely first

Work down the list and stop when it's fixed.

  1. It's asleep when the scan runs

    How to tell. The scan finishes with nothing found. A BLU device only sends when something happens, so the scan can miss it unless you wake it while the scan runs.
    • In the app, press the button during the scan

      In the Shelly app, choose Add device, then Add via Bluetooth. Once the scan has started, press the device's button once so it appears in the list.

    • On a web page, put it in pairing mode

      Shelly says the device has to be in pairing mode to be found by a web page scan. On most BLU devices, hold the button for 10 seconds. On the ZB models, press it 4 times quickly instead.

    • Don't press 5 times on a ZB model

      5 quick presses starts Zigbee pairing on the ZB models, not Bluetooth.

    • Scan again within a minute

      Pairing mode ends after about a minute. If the scan missed it, click Scan again and put the device back in pairing mode.

  2. No Shelly is acting as its gateway

    How to tell. In the app, the Bluetooth gateways step lists none of your Shellies, or the sensor shows No Gateway. Shelly says a BLU device needs a Wi-Fi Shelly to act as its Bluetooth gateway.
    • Turn on the gateway in the app

      Open a Shelly near the BLU device in the app, go to its settings, then Bluetooth, and turn on Enable and the Bluetooth gateway toggle.

    • Check Bluetooth on the Shelly's web page

      On a Gen4 with current firmware, Bluetooth turns itself on when it's needed. Go to Settings, then Bluetooth, and check it says Active.

    • Pick the gateway for the sensor

      In the sensor's settings in the app, choose which Shelly is its gateway. More than one can do the job, and the app shows which one reported last.

  3. It's too far from the gateway

    How to tell. It only works when it's close to the Shelly, or drops out in one spot. Shelly gives BLU devices a range of up to 10 m indoors and 30 m outdoors, depending on the building.
    • Use a gateway in the same room

      Pick a Shelly in the same room as the gateway, as Shelly recommends.

    • Add a gateway where there's none

      A BLU Gateway plugs into a USB charger, so it can go where there's no mains Shelly.

  4. The Gen4 gateway is in Zigbee mode

    How to tell. The Gen4 was switched to Zigbee, by pressing its button 5 times or by switching its firmware. Shelly's docs say BLU devices, Bluetooth scanning and the cloud relay aren't available on a Gen4 in Zigbee mode.
    • Use another Shelly as the gateway

      Pick a Shelly that isn't in Zigbee mode, in the same room, as the BLU device's gateway.

  5. It was added somewhere else

    How to tell. It works in the Shelly app but isn't on the gateway's web page, or the reverse. The app passes BLU readings through Shelly Cloud; a web page adds it to that one Shelly, locally.
    • Add it on the web page for local use

      On the gateway's web page, click Components, then the + beside Bluetooth (BTHome) devices, and put the BLU device in pairing mode.

    • Use BTHome in Home Assistant

      Home Assistant's Shelly integration doesn't support BLU devices. Add them with the BTHome integration, with a Shelly or a Bluetooth adapter in range to listen for them.

  6. It's encrypted and the gateway has no key

    How to tell. It shows up, but the readings never arrive. Encryption is turned on in the app under the BLU device's Security settings, and after that, only a gateway with its key can read it.
    • Enter the key on the web page

      On the gateway's web page, click Components, open the BLU device and click Configure, then enter the encryption key. Shelly says the key comes from its Shelly BLU Debug app.

    • Enter it in Home Assistant

      Home Assistant asks for the same key, which it calls the bindkey, when you add an encrypted device with BTHome.

  7. The battery is flat

    How to tell. Pressing the button does nothing: no flash, no reading. The app shows the battery as a percentage once the device is added.
    • Replace the battery

      Most BLU devices take a CR2032 coin cell; the BLU Motion takes a CR2477. Fit it the right way round, then press the button to check the light flashes.

    • Keep coin cells away from children

      Shelly warns that a swallowed coin cell is dangerous. Keep new and old batteries out of reach.

  8. It still holds old pairings

    How to tell. It was added before, to another gateway or account, and won't pair again. A factory reset erases its pairing keys and settings.
    • Factory reset it

      Take the battery out and put it back, then straight away hold the button for 30 seconds. Shelly says the reset only works shortly after the battery goes in.

    • Remove the old entry, then add it again

      Delete it from the app or the gateway's web page, then add it again from the start.

    • Update the firmware first

      Shelly recommends the latest firmware on both the gateway and the BLU device. Newer BLU models need newer gateway firmware.

On your device

Shelly BLU Motion The button is under the back cover
  • Open the back cover

    Put a 3 to 5 mm flat screwdriver in the slot and turn it gently to pop the back cover off. The button and the CR2477 battery are inside.

  • Pair it

    Hold the button for 10 seconds. Shelly says the light gives short blue flashes and it waits a minute for a connection.

Shelly BLU Motion
Shelly BLU Door/Window ZB Four presses, not five
  • Pair it over Bluetooth

    Press the button 4 times quickly. The light flashes once every 2 seconds for a minute while it waits. Twice every 2 seconds means you started Zigbee pairing instead.

Shelly BLU Door/Window ZB
Shelly BLU H&T ZB Two ways to pair
  • Pair it over Bluetooth

    Press the button 4 times quickly, or hold it for 10 seconds. The red light flashes once every 2 seconds for a minute while it waits.

Shelly BLU H&T ZB

Frequently asked questions

Not when they're added on a Shelly's web page; that works locally. Scenes in the Shelly app pass the readings through Shelly Cloud, so those need it.

Yes. In the app you can pick several gateways, and the sensor's page shows which one reported last.

Shelly's BLU devices only send when something changes, plus a battery report every 6 hours. A door that stays shut sends very little, which is normal.

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