Totally resetting the PurpleAir

Hi all,

I am trying to set up a PurpleAir which was previously working OK, but this time I am having an enormous set of problems with it. I have followed the instructions on the sensor start-up page about a hundred times, as well as this page about connecting to Wi-Fi.

When I connect to the sensor’s PurpleAir-146e Wi-Fi SSID, and go to, it gives me a list of available Wi-Fi networks I can connect to. When I choose the correct one, the display at the top says " WiFi Connected | Checking status…" and in the upper right corner it has the correct Wi-Fi network selected with 4/5 bars of service. This is all good so far. In the past, this is when the sensor’s internal hotspot would usually disconnect, connect to my home network, and then I’d register it on the map.

HOWEVER, for some reason, the sensor does not seem to actually connect to the network: the PurpleAir-146e hotspot remains active. I have tried everything I can think of: resetting the router, resetting the sensor, running through the setup guide several times, etc. The password is right, it’s using 2.4 GHz instead of 5 GHz, it’s using WPA2-PSK, and so on.

What on earth could be the problem? This has always worked in the past. Can I just totally factory reset the unit somehow?

Solved! Looks like the problem was with the transformer I was using. Different power cable solved it.


Can you elaborate on how you debugged this? I’m hitting the same issue, but I’m using the power cable that came with it so I don’t know why it wouldn’t work.

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Same problem. Do you know if your wifi is WP3 encrypted.
I too am using the same cable that came with it.

You can grab the PurpleAir Utility app The PurpleAir Utility and once you’re connected, there’s an action in the ‘Select a Flash Action’ menu for Erase ALL Memory (select that, then click Flash). You’ll want to grab a copy of the current firmware first, so you can follow-up the erase step with flashing the correct firmware (same menu as the erase, Choose a firmware file, then Flash).

At that point, you should be fully reset, if that’s what you’re wanting to try.