WiFi Troubleshooting

This article walks you through connecting a PurpleAir sensor to WiFi. Once you have successfully completed a section, continue to the next section below or follow a link if provided. Troubleshooting steps are included for each step in case you experience any problems with this process.

Before we begin, you’ll want to make sure your network is one the sensor can connect to. You’ll want to consider the below questions to see if there could be a network configuration issue.

  1. Does your network use a captive portal? This is a page requiring you log in or agree to terms before allowing internet access. These are commonly found in companies, universities, or public Wi-Fi networks.

  2. Does your network use an Eero router? PurpleAir devices will not work with default Eero router settings.

If you answered yes to either of these questions, you’ll need to follow the steps in our network checklist article for your sensor to connect.


Checking Power

Before anything network-related, you’ll want to check that your sensor is powered on. Plug in your sensor and ensure that the LEDs are shining. If they aren’t, follow the steps in our Power Troubleshooting Guide.


Finding the Sensor’s WiFi Network

Once your sensor has successfully powered on for at least a minute, you’ll want to look for a WiFi network named PurpleAir-**** (the stars should be the last 3 or 4 digits of your sensor’s device ID). This WiFi network is broadcast by your sensor for setup.

If your sensor has a microSD card, make sure to remove it for this step. The sensor’s WiFi network can take longer to appear when the microSD card is inserted.

  1. If the PurpleAir-**** WiFi network does not appear, turn off all WiFi networks it may have previously been connected to. After 10 minutes, the WiFi network PurpleAir-**** should be visible again.

  2. If the PurpleAir-**** WiFi network still isn’t appearing after 10 minutes, our Reset the WiFi Network Connection article contains alternative ways to connect to the sensor without the PurpleAir-**** WiFi network.


Connecting to the Sensor’s WiFi Network

Once you can see the PurpleAir-**** WiFi network, connect to it using your phone or computer. You may see a message saying that PurpleAir-**** has no internet connection. This is expected, as you are connecting directly to your PurpleAir sensor, which does not provide internet access.

We recommend connecting to your sensor with a mobile device. Computers can be used, but more frequently have problems when connecting to sensors.

Once connected to the PurpleAir-**** WiFi network, wait for 5-10 seconds. During this period, a web page should automatically appear. When this occurs, proceed to Connecting the Sensor to Your WiFi.

It’s possible your device may automatically disconnect from the PurpleAir-**** WiFi network. This is because the PurpleAir-**** network does not provide internet, and your device might prefer to remain connected to another WiFi network with internet. If this occurs, try the following troubleshooting steps:

  1. Forget the WiFi network your device is currently connected to.

  2. Verify that your device is not connected to a WiFi network.

  3. Try reconnecting to the PurpleAir-**** network.

If a message saying “Unable to connect” appears when trying to connect to PurpleAir-****, try the following troubleshooting steps:

  1. Wait for 1 minute and try reconnecting. This message can appear when the sensor has not been powered on long enough.

  2. Forget any current WiFi connections.

  3. Forget the PurpleAir-**** WiFi network if it’s remembered by your device.

  4. Reconnect to the PurpleAir-**** WiFi network.


Connecting to the Sensor’s Configuration Page

Once you’re connected to the PurpleAir-**** WiFi network, the sensor’s configuration page should automatically appear. If this page appears for you, proceed to Connecting the Sensor to Your WiFi. If not, try the troubleshooting steps below.

If the sensor’s configuration page doesn’t automatically appear, try the following troubleshooting steps:

  1. Double-check that your device is still connected to the PurpleAir-**** WiFi network. Ensure that the network is visibly marked as the connected network for your device. If not, return to the Connecting to the Sensor’s WiFi Network section above.

  2. Once you’ve verified that you’re connected to the PurpleAir-**** WiFi network, open a web browser on the same phone or computer you connected to the PurpleAir-**** WiFi network. However, instead of going to a web page, enter the following IP address: 192.168.4.1

Once you’ve entered the IP address into your browser, try connecting to it just like a website. This should bring you to the sensor’s configuration page. If the configuration page does not appear, check that the IP address was entered correctly and that you are still connected to the PurpleAir-**** WiFi network on the device you’re currently using. Using this IP address will only work while your device is connected to the PurpleAir-**** WiFi network.

If entering 192.168.4.1 does not work on a mobile phone, try disabling cellular data. Mobile devices will sometimes try to use cellular when connected to WiFi without internet.


Connecting the Sensor to Your WiFi

Once you’re on the device’s configuration page, click on the link labeled WiFi Settings.

WiFi Settings

Once there, click on the bubble next to your WiFi network’s name. This bubble will fill in blue to indicate that it’s selected. If your network is hidden, select “Hidden Network” and enter the WiFi’s name in the box that appears (this will need to match exactly and include any spaces).

Once your WiFi network is selected, enter your WiFi password in the box labeled “Password.” Click the “>> Save” button once your password is entered.

If you’re unable to see your WiFi network in this list, try the following troubleshooting steps:

  1. Check that you can see the WiFi network using a different device from the one you’re currently using to set up your sensor. Make sure that the other device can access the Internet using this WiFi network.

  2. Try selecting the “Hidden Network” option and entering the name of your WiFi network in the box that appears. The name must be exactly correct, including any spaces. Then, enter your password and try connecting like before.

  3. Restart your WiFi router by unplugging it for at least 10 seconds and plugging it back in. Wait for the WiFi network to appear for a separate device, like in step one. Once the WiFi network has reappeared, click “refresh” on the sensor’s WiFi settings page and see if the WiFi network is now available.

  4. It’s possible that your WiFi network is not 2.4 GHz. To determine this, you will likely need to view your router’s settings. Further details are found in our network checklist.

Confirming Your Sensor is Successfully Connected

The sensor will likely provide a link to register once your sensor is connected. This will not work while you’re still connected to the sensor’s PurpleAir-**** WiFi network. Once you’ve confirmed your sensor is connected with the steps below, we recommend manually going to https://www.purpleair.com/register or using a different link.

Once you’ve entered the password for your WiFi network, a message will appear at the top of the setup page.

  • If it says “WiFi disconnected,” continue below to WiFi Password Troubleshooting.

  • If it says “WiFi Connected Looking good!” with a green or orange color, the WiFi password you entered is correct.

  • If it says “WiFi Connected” with a gray color, the password you entered is correct but the sensor can’t contact PurpleAir.

Once you receive a message containing “WiFi Connected," regardless of color, examine the boxes in the bottom left of the page. These are WiFi Status Indicators, and will definitively show if your sensor is connected.

The NTP and UPD indicators circled in the image below should be green. If your sensor says it’s connected, but the NTP or UPD boxes are not green, consult the steps in our network checklist.

Most of the time a sensor with successful NTP and UPD indicators can contact PurpleAir without issue. Although rare, it is possible for the sensor to only be able to contact certain PurpleAir services. You can tell if this is the case by waiting at least two minutes once you have received a “WiFi Connected” message, and checking if the “PAA” status indicator is green. If not, follow the steps in our network checklist.

Where to Go From Here

Once your sensor is connected to WiFi and the NTP and UPD status indicators are green, it is successfully connected to the internet!

Make sure to disconnect your phone or computer from the PurpleAir-**** WiFi network and reconnect to your home WiFi network. You’ll also want to re-enable cellular data if it was previously disabled for troubleshooting.

If you’re unable to successfully connect your sensor to WiFi, continue reading for further troubleshooting steps.

WiFi Password Troubleshooting

If your sensor won’t connect to WiFi, you’ll first want to re-enter your WiFi password. It can be very easy to accidentally mistype a password, and no other troubleshooting steps will work if the password was entered incorrectly. Before clicking the “>> Save” button, read the entered password and ensure there are no typos or other errors. Once you’ve confirmed it’s correct, click the “>> Save” button. You’ll then want to confirm your sensor is connected using the previous steps above.

If re-entering your password didn’t work, you’ll want to confirm with 100% certainty that the password for your WiFi network is correct. To do this, forget your WiFi network on a separate device and use the password to reconnect. Once your device is reconnected and you’ve confirmed the password is correct, return to the sensor’s configuration page and try the following troubleshooting steps:

  1. Try connecting the sensor to your WiFi network, but enter an incorrect password.

  2. Try connecting the sensor to your WiFi network and enter the correct password.

  3. Select the same WiFi network and enter the correct password again.

If the exact same WiFi password was entered both times, the configuration page will say “No Changes.” After performing these steps, you will have confirmed that:

  1. You have the correct WiFi password.

  2. It was entered correctly on the device.

PurpleAir sensors will only remember one WiFi password at a time, so entering an incorrect password will completely reset the device’s network connection details.

Confirming Your WiFi Network has Internet Access

Once you’ve confirmed your password is correct, you’ll want to check that the WiFi network you’ve connected the sensor to has an internet connection. Connect a device other than your sensor to the WiFi network, and confirm that it can access the internet.

Resetting Your WiFi Router

Once you’ve confirmed your password is correct and the WiFi network has internet access, reboot your router by unplugging it for at least 15 seconds and plugging it back in. Check that the WiFi network appears for a different device and it has internet access. Once the WiFi network has reappeared with internet, try connecting your sensor to WiFi.

Why Does the PurpleAir-**** WiFi Network Still Show?

If your sensor has been connected to WiFi, but the PurpleAir-**** WiFi network is still showing, it may be for one of the following reasons:

  1. The sensor does not have an internet connection. This may mean the sensor has become disconnected from WiFi, or the sensor cannot contact PurpleAir. Try following the steps above to reconnect your sensor to WiFi and confirm it’s successfully connected.

  2. Even if the sensor can contact PurpleAir, the PurpleAir-**** WiFi network will remain visible as long as a device is connected to it. Make sure no device you use is connected to the PurpleAir-**** WiFi network.

Network Checklist

If you’re still unable to connect your sensor to WiFi using the troubleshooting steps above, you’ll want to examine our network checklist. The checklist contains more advanced troubleshooting steps to ensure your WiFi network is compatible with your sensor.

If you’re still unable to connect your sensor to WiFi even after using the network checklist, leave a comment below or send an email to contact@purpleair.com. Our support team would be happy to provide further assistance.


Learn More

After Installation
Sensor Maintenance
What Do PurpleAir Sensors Measure and How Do They Work?