AirGradient Forum

Help Us with the Wi-Fi Issue of Firmware 3.6.0

Support
#1

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Hi folks!

I am Tai from AirGradient.

We have reports from our community that they have experienced a Wi-Fi disconnection issue on their AirGradient ONE and/or Open Air, which is likely to be linked with the new firmware V3.6.0 that was rolled out on January 19, 2026.

I’ll put some reports here for the context:

While we are actively finding out the possible root cause of the issue. I would like to apologize for the inconvenience caused (as I am personally also a part of testing this myself).

I have included an easy step to downgrade your AirGradient monitor to the previous version to mitigate the issue at the end of this post.

For those who have experienced the issue. We would also love to have your help in providing some technical information on your network setup and the monitor’s configuration to better understand the issue and diagnose the root cause of it.

These are the lists you can reply to this post (feel free to let me know if you are unsure of anything):

  1. Model number of the monitor that has the issue? (I-9PSL-DE, O-1PST, etc.)

  2. Please describe the symptom of the issue you experienced. For example, it randomly disconnects from your Wi-Fi, or you can observe some patterns in its behavior.

  3. What does the OLED screen of the monitor show when it is disconnected? And what is the color of the LED on the left of the monitor (red, purple, etc.)?

  4. Network setup: Describe your network setup. Please also specify the brand and model of each network equipment.

  5. AirGradient monitor configuration - accessible via web browser with a phone or computer connected to the same Wi-Fi as the monitor that has the issue using: http://airgradient_<serial_number>.local/config

For example my monitor S/N is d83bda1b85fc
Then the URL will be http://airgradient_d83bda1b85fc.local/config

  1. Is your Wi-Fi network using a unified band (a combined Wi-Fi name without separating 5GHz and 2.4GHz)?

  2. Is your Wi-Fi a mesh system, have multiple access points, or use Wi-Fi extender?

  3. Do you have your Wi-Fi DHCP server configured to assign a static IP address for connected devices?

  4. Does the monitor connect to the AirGradient dashboard?

  5. Does the monitor connect to Home Assistant or other platforms?

  6. Is this Wi-Fi issue gone after you downgrade your AirGradient monitor from firmware 3.6.0 to 3.4.1?

How do you downgrade your AirGradient monitor to the previous firmware?

If you use AirGradient Dashboard, please see my reply in: Indoor monitor disconnect and does not reconnect - #17 by Tai_AirGradient

If you don’t use AirGradient Dashboard or prefer flashing an older firmware via PC, please see: Indoor monitor disconnect and does not reconnect - #19 by Tai_AirGradient

We always appreciate your time and input, helping us improve products to serve our community.

Thank you all!
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Tai

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An AI-slop image to make this post look a little bit less boring

Indoor monitor disconnect and does not reconnect
#2

I have a I-9PSL (doesn’t seem to have any other characters after that) and a O-1PST. Both are connected to the same Wi-Fi, but only the O-1PST seems affected.

Looking at the Home Assistant history, I can see that the O-1PST got disconnected two times so far: first it was on 2026-01-19 right before 3PM CET. I only noticed it late in the evening. I unplugged the USB-C cable and after plugging the cable back in, it was fine. Second disconnect was on 2026-01-26 after 1PM CET; I noticed again in the evening and I restarted it.

As a suggestion: in Home Assistant, I only see that the firmware is up to date, it doesn’t specify the actual firmware in use. It would help to see exactly when the firmware was upgraded…

O-1PST doesn’t have a screen.

I have a Fritzbox (German brand of router/AP combo). Nothing fancy, no VLANs. I have IPv6 enabled, but the AGs don’t seem to support it, unfortunately… O-1PST is 2m away from the Fritzbox, I-9PSL is about 5m away.

  • O-1PST that is affected:
{
  "country": "AT",
  "pmStandard": "ugm3",
  "ledBarMode": "co2",
  "abcDays": 8,
  "tvocLearningOffset": 12,
  "noxLearningOffset": 12,
  "mqttBrokerUrl": "",
  "temperatureUnit": "c",
  "configurationControl": "cloud",
  "postDataToAirGradient": true,
  "ledBarBrightness": 100,
  "displayBrightness": 100,
  "offlineMode": null,
  "model": "O-1PST",
  "monitorDisplayCompensatedValues": false,
  "disableCloudConnection": false,
  "corrections": {
    "atmp": {
      "correctionAlgorithm": "ag_pms5003t_2024",
      "slr": null
    },
    "rhum": {
      "correctionAlgorithm": "ag_pms5003t_2024",
      "slr": null
    }
  },
  "httpDomain": "",
  "extendedPmMeasures": false
}
  • for reference, here’s also the I-9PSL that is NOT affected (so far):
{                                                                                                                                                                                             
  "country": "AT",                                                                                                                                                                            
  "pmStandard": "ugm3",                                                                                                                                                                       
  "ledBarMode": "co2",                                                                                                                                                                        
  "abcDays": 8,                                                                                                                                                                               
  "tvocLearningOffset": 12,                                                                                                                                                                   
  "noxLearningOffset": 12,                                                                                                                                                                    
  "mqttBrokerUrl": "",                                                                                                                                                                        
  "temperatureUnit": "c",                                                                                                                                                                     
  "configurationControl": "cloud",
  "postDataToAirGradient": true,
  "ledBarBrightness": 100,
  "displayBrightness": 100,
  "offlineMode": false,
  "monitorDisplayCompensatedValues": false,
  "model": "I-9PSL",
  "disableCloudConnection": false,
  "corrections": {
    "atmp": {
      "correctionAlgorithm": "none",
      "slr": null
    },
    "rhum": {
      "correctionAlgorithm": "none",
      "slr": null
    }
  },
  "httpDomain": "",
  "extendedPmMeasures": false
}

Yes, I only have one SSID.

No, just one AP.

No. Maybe worth mentioning that the Fritzbox router/AP is NOT the DHCP server, I have a separate device for that (pihole running on a Odroid-C2, if that matters).

Yes

Yes, it’s intergrated with HA, but I still have cloud as source of config.

I haven’t downgraded, both devices are still on 3.6.0. I have another I-9PSL in another location also on 3.6.0, but that also has been stable so far.

1 Like
#3

My details were already in the “Indoor monitor disconnects and does not reconnect” thread, and I updated to provide the few extra details requested here that were not already there.