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Shelly BLU Gateway Gen3: update to 2.0.2 fails or stalls – what helped owners

Shelly Device: Shelly BLU Gateway Gen3 (S3GW-1DBT001), often used with the BLU TRV · Updated · Auch auf Deutsch

Firmware as of: As of 3 Nov 2026 per the official Gen2+ changelog: 2.0.2 (2026-10-09) fixes slow/stalled updates on the BLU Gateway Gen3. Later versions 2.0.3 and 2.1.1 (both 2026-10-26) update the CA bundles per the changelog; which version your gateway is actually offered was not checked for this page.

Generations: Gen3, BLU

What you see: The Shelly app or web interface offers the update to 2.0.2 for the BLU Gateway Gen3. You start it, the progress bar runs (often very slowly), but at the end the old version is still installed or the web interface shows an error. Often the updates of paired BLU TRVs stall at the same time.

What it means: According to the official changelog, firmware 2.0.2 from 2026-10-09 fixes exactly this kind of problem: "BLU Gateway Gen3: Fix slow/stalled updates". But the fix only applies once 2.0.2 is installed; the update to it still runs on the old firmware. A moderator on the Shelly forum updated his gateway without problems, so this isn't a general fault but affects individual setups.

Cost: €0 / CHF 0.

Likely causes (from owner reports)

  • The download breaks off part-way. A debug log in the Shelly community showed, after about 20 minutes and 42 %: Update failed (DATA_LOSS: ZIP flush error : premature end of data), will not reboot.
  • The gateway is busy with paired BLU devices (e.g. BLU TRV) or running scripts. One owner could only update after deleting his BLU TRV.
  • After the update, the web interface still shows the old version from the browser cache (tip from the Shelly forum about other Shelly devices).

Step 1: Check whether the update really failed 2 min

  1. Watch the LED. According to the Shelly Knowledge Base, a flashing red/blue light means an OTA update is running. Don't unplug the gateway during this time.
  2. Open the gateway's web interface in your browser via its IP address and reload the page. Device settings › Firmware shows the installed version (also in the footer).
  3. If it already says 2.0.2, you're done.

Step 2: Improve the conditions for the update 5 min

A forum post gives these tips for gateway updates:

  1. Turn off Eco mode (Device settings › Eco mode).
  2. Stop all scripts. If scripts run on startup, temporarily disable that option.
  3. Reboot the gateway (Device settings › Reboot).
  4. Check the Wi-Fi signal. A weak signal makes downloads unreliable (see Shelly offline and Wi-Fi problems). The gateway plugs into a USB-A port, so moving it to a port closer to the router is often easy.

Step 3: Start the update from the local web interface 10–30 min

  1. In the web interface, go to Device settings › Firmware, check for updates and start the stable update.
  2. Be patient: in the reports the bar moved very slowly. Keep the browser tab open.
  3. To see the cause: keep the debug console open in a second window, or enable the debug log under Diagnostics (tip from the forum). The Knowledge Base says the debug log slows the device down; turn it off again afterwards.

The Shelly Debug app doesn't help here: the gateway is a Wi-Fi device, and the app is meant for BLU Bluetooth devices (moderator on the Shelly forum and in the Shelly community).

Step 4: Temporarily remove the paired BLU TRV 10 min

One owner reports on the Shelly forum: after deleting his BLU TRV, the gateway update to 2.0.2 worked, and afterwards the TRV could be updated again too.

  1. In the gateway's web interface, open the TRV and choose Delete. According to the Knowledge Base you'll have to pair it again afterwards.
  2. Start the gateway update as in step 3.
  3. Then add the TRV again via + BLE Device.

Step 5: Factory reset the gateway, then update straight away 20–40 min

An owner in the Shelly community solved it like this: factory reset of the gateway → gateway update from 2.0.1 to 2.0.2 → pair TRV again → TRV update → re-attach door/window sensors to the TRV. His summary: resetting the gateways was the key.

  1. Note your settings first (Wi-Fi, paired devices, scenes). A factory reset erases everything.
  2. Factory reset: per the Knowledge Base, hold the reset button for 10 seconds (or Device settings › Factory reset).
  3. Bring the gateway back onto Wi-Fi and do the firmware update first, before pairing any BLU devices.
  4. Then add the TRV and sensors again. The same owner afterwards had to assign the door/window sensors manually to the right gateway in its Bluetooth settings before the app showed their states again.

Note: on the Shelly forum an owner with three gateways reports that factory resets didn't help him. In that case continue with step 6 or contact support.

A co-admin on the Shelly forum suggests loading the official gateway firmware via a link in the web interface from a small file server on your home network; he gives https://updates.shelly.cloud/update/BluGwG3 as the source of the current firmware. We haven't tested this route ourselves. Important:

  • Only use official Shelly firmware for exactly this device. According to the Knowledge Base, custom firmware irreversibly voids the warranty.
  • Shelly's staff guide shelly.guide recommends contacting support for Gen2+ devices instead of flashing manually (see Firmware update failed).

Afterwards: update the BLU TRV

Once the gateway runs 2.0.2, update the TRVs via the gateway. If a BLU device doesn't respond at all after an aborted update, the bootloader route with the Debug app helps: BLU device dead after update.

When to contact support

  • The update still fails after reboot, Eco mode off, scripts stopped and a factory reset.
  • The web interface keeps showing an update error.
  • The gateway no longer responds after an update attempt.

Shelly support (official). Give the firmware ID from Device settings › Firmware, what you tried and, if available, the error message from the debug log.

Sources

FAQ

Can I update the BLU Gateway Gen3 with the Shelly Debug app?

No. According to a moderator on the Shelly forum and in the Shelly community, the gateway is a Wi-Fi device; the Debug app is meant for BLU Bluetooth devices. A greyed-out "Mass OTA" button in the app is therefore not a sign of a fault.

Why doesn't 2.0.2 help if 2.0.2 fixes stalled updates?

The fix only applies once 2.0.2 is installed. The update to it still runs on the previous firmware. That's why it pays to improve the conditions for that one update (reboot, Eco mode off, scripts stopped, TRV removed).

Should I update the gateway or the BLU TRV first?

One owner whose BLU TRVs also wouldn't update only got further after bringing the gateway to 2.0.2 first and then updating the TRVs via the gateway. That's an owner report, not an official order.

Can I unplug the gateway during the update?

No, not while the update is running. According to the Shelly Knowledge Base, a flashing red/blue light means an OTA update is in progress. Wait until the flashing stops or the web interface reports an error.

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