Q: My Zen LED's have gone dark. Did they fail?

A: Zen (and Touch) sensors contain a new “Tap” feature to adjust the brightness of the LED’s. Double tapping the sensor will cycle the LED’s through the different brightness settings, so try double tapping the sensor and you should find the LED’s come back to life.

We will work on improving this feature to avoid unintentional changes to the brightness, like with someone walking on the deck nearby the sensor.


Hello, my indoor sensor works and appears on the map. But the LED light isn’t on. I took off the plastic, and if I hold down the LED it illuminates green. Then if I release the button, it goes dark. Please advise as to best way to troubleshoot. Do you have a video on topic?

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We responded to your email to help resolve your issue. If you have further questions, feel free to comment on the community or reach out to our support team again.

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I seem to have this same problem. What part of the sensor do I double tap on? I re registered to make sure it was on and to a decent #. It is. But no lights.

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Double tap the top of the sensor. An example video is found here. If it doesn’t change brightness, try tapping harder as gentle taps may not register.

Also keep in mind that only PurpleAir Touch and Zen sensors can be tapped to change brightness. Older PA-I-Indoor devices do not have this feature.

If your sensor still doesn’t change brightness, send an email with the device ID to contact@purpleair.com.


Btw, we had a huge thunderstorm here yesterday and the thunder turned off the purple air zen ring light. So if the sensitivity could be tweaked that would be great…

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I had the same thing happen (LED ring reflecting the current AQI no longer lights up). The blinking blue and red LEDs still flash.

I have the Zen as well.

Not a huge deal because I mounted it outside and don’t want it to bother my neighbors. But, figured I’d like to hear a solution if one exists.

It still seems to be collecting AQI data with no problem.

Thank you,

Hi @klkeefer, if this is your new sensor, then this is due to the registration settings. Your sensor is currently registered with the LED Mode set to “Off, NO LED’s” and the LED Brightness set to zero. To turn on the LED ring, you’ll need to update your sensor’s registration, and change these settings to the values below:

  • LED Mode will need to be set to either “Power, SD Status and Full Color AQI” or “Full Color AQI Only”. Full color AQI refers to the LED ring.
  • The LED Brightness (%) will need to be set to a nonzero value. The default value is 35.
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I found that if I turn my Zen setting below 3 for brightness, then it is effectively off.