Sadly, this is most likely a formaldehyde sensor failure. Your unit variant uses analogue connection to sensors, so there is little we can investigate here. Newer A3’s communicate with the formaldehyde sensor via a serial connection.

Drop me an email on support@uradmonitor.com if you want me to service it.

You will often see the VOC AQI perfectly aligned with Formaldehyde readings. I love it, since the two sensors are using very different tech for their operation.

three long beeps means “cannot connect” and lead to a reboot, that does yet another beep, resulting in the four beeps that you heard.

@baskin, it is never too late! Looks good!

Thanks for your prompt report! It was a bug that is now fixed. Please try again.

Hi @arnekeller! Any luck on this? Need any help?

There’s indeed an elevated radiation level there, confirmed by several units. The location is one of the manufacturing factories, where I get the units assembled and tested. While this is test data, I purposely left it visible. There are no radiation sources being used there, it is just the background level considerably higher. Once shipped, the very same units lower their readings.

Let me know if you’d like any additional info on this.

Thanks

Can you open the unit’s IP in your browser to see what the internal webserver puts out? It is possible the high voltage inverter is failing to produce 380V, resulting in a reboot. Then it goes for DHCP lease again (~12sec) and so on.