Shelly devices won't connect after changing router or Wi-Fi: how to fix it

You've changed router or provider and suddenly none of your Shelly devices respond. They don't appear in the app, and your phone can't find them. It's one of the most frequent support queries we get, and it has a solution in almost every case.

The key is understanding why it happens: your Shelly stores the network name and password you set it up with. When that network disappears, the device keeps looking for something that no longer exists. It keeps working (if it's a relay, the physical switch responds), but you lose remote control.

First of all: do you still have the old router?

This question changes everything. Depending on whether you can turn it on or not, you have three paths with very different amounts of effort.

Scenario A: the two-minute solution

If you're still in time to set up the new router, give it the same network name (SSID) and the same password the old one had.

Your Shelly devices will reconnect on their own, without you having to touch a single device. It's especially valuable if you have units embedded behind a switch or inside a mechanism box, where reaching the physical button is awkward.

Most routers let you change the SSID and the password from their admin panel. It's worth doing that rather than reconfiguring twenty devices.

Scenario B: migrate them all at once

If you want a fresh network name but the old router is still on, the Shelly app has a feature many people don't know about: the batch Wi-Fi change.

The procedure is this:

1. Have both routers on at the same time.
2. Leave DHCP active only on the new router. If both hand out IP addresses there will be conflicts.
3. Connect the phone to the old network.
4. Open the Shelly app and go into All devices.
5. Tap the three dots (⋮) in the corner and choose Batch Wi-Fi change.
6. Enter the new SSID and password and confirm.

The devices update and switch to the new network on their own.

Do it before removing the old router. Once you disconnect it, this shortcut is no longer available and you have to go one by one.

Scenario C: device by device in AP mode

If the old router no longer exists and you can't replicate the network, the manual method remains. It always works.

1. Press and hold the device button for 5 seconds. The LED will turn blue: it's in access-point mode.
2. From your phone, connect to the network the Shelly itself broadcasts. It's called something like ShellyPro3EM-XXXXXX. Don't worry if the phone warns there's no internet.
3. Open the browser and go to 192.168.33.1.
4. Go to Settings → Wi-Fi, enter the name and password of your new network and save.
5. Reconnect the phone to your usual network.

If the Shelly's network doesn't appear, cut its power for a few seconds and power it back up before pressing the button.

Why sometimes it doesn't work even then

Here's the real reason for most cases that reach support. Modern routers come with default settings that block home-automation devices.

Shelly devices only see the 2.4 GHz band

Their radio is 802.11 b/g/n and works at 2400-2495 MHz. They don't detect 5 GHz. If your new router puts both bands under a single network name (what's called band steering), the device may never find the band it needs.

The solution is to separate the bands with different names, for example "MyNetwork_2G" and "MyNetwork_5G". If your router doesn't allow it, temporarily turn off the 5 GHz while setting up.

WPA3 isn't backward-compatible

Many new routers come with WPA3 enabled by default. Shelly devices need WPA2 at least, and with WPA3 in exclusive mode they won't connect. Set it to WPA2 or to mixed WPA2/WPA3 mode.

The automatic channel causes problems

Set the 2.4 GHz band's channel to 1, 6 or 11 and the bandwidth to 20 MHz. These are the non-overlapping channels and give much more stable connections for IoT devices.

Special characters in the name or password

Problems have been reported with very short SSIDs or unusual symbols in the password. If nothing works, try a simple alphanumeric password to rule it out.

Diagnose by the LED color

The device itself tells you where the problem is. No need to guess:

The most telling case is yellow: it means the Wi-Fi is working perfectly and the problem is in internet access or Shelly's cloud. In that case don't touch the device's network settings, check the router's connection.

These codes correspond to Gen2 and Pro devices. Gen1 uses a different pattern.

Frequently asked questions

Do I lose the settings and history when changing networks?

No. Changing the Wi-Fi only modifies the connection data. Your automations, calibrations and stored data stay intact. What does erase everything is a factory reset, so leave that as a last resort.

I have a Shelly embedded in the wall and can't reach the button

That's exactly the case where it pays to replicate the old SSID and password on the new router. If that's no longer possible, some Gen2 and Pro devices allow setup via Bluetooth from the app, which avoids having to press anything.

They connect but disconnect every so often

It's usually channel saturation or marginal coverage. Set the channel to 1, 6 or 11 with 20 MHz width. In installations with many devices, some home routers struggle to manage dozens of clients on 2.4 GHz.

I have a mesh network and they don't quite work

Restart the main router first and then the satellites or repeaters. Bear in mind that some battery Shelly devices stay fixed to the node they were set up with and don't switch access point, to save battery.

Can I use them without internet?

Yes. Shelly devices work locally. You can control them from their web interface within your network or integrate them via MQTT into Home Assistant without depending on the cloud.

When do I do a factory reset?

Only when everything else has failed. It's done by holding the button for 10 seconds and it erases all the device's configuration, including automations and calibration settings.

Summary: what to do and in what order

1. Can you give the new router the old SSID and password? Do it and you're done.
2. Is the old router still on? Use the batch Wi-Fi change.
3. If not, first check that the new router has 2.4 GHz active, with its own name and on WPA2.
4. Reconfigure each device in AP mode from 192.168.33.1.
5. Factory reset only as a last resort.

Still stuck? Write to us with the model of your Shelly devices, the color of their LED and the make of the new router, and we'll help you resolve it. Technical support in English.

If the problem isn't the network but odd readings on a meter, check our guide on why the Shelly EM reads more than expected.