# Zen sensor only shows red and is constant

**URL:** <https://community.purpleair.com/t/zen-sensor-only-shows-red-and-is-constant/22956>\
**Category:** Troubleshooting\
**Created:** [October 13, 2026, 4:48pm UTC](https://community.purpleair.com/t/zen-sensor-only-shows-red-and-is-constant/22956 "2026-10-13T16:48:56Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Loisar](https://avatars.discourse-cdn.com/v4/letter/l/ce73a5/32.png) [@Loisar](https://community.purpleair.com/u/Loisar)\
**Post date:** [October 13, 2026, 4:48pm UTC](https://community.purpleair.com/t/zen-sensor-only-shows-red-and-is-constant/22956/1 "2026-10-13T16:48:56Z")

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My Zen sensor only displays red. Nothing else. the map shows a greyed out “0” circled because I use the sensor indoors. How can I get the sensor itself to display the corresponding actual color of the indoor reading, and how can I get the number on the map to not be greyed out?