CO2 module returns always value 10000

I have installed a new CO2 monitor kit two days ago. Tags are working fine and returning correct values, but for CO2 module I have receiving always the same value 10000. I have tried also manual calibration started by longer holding of button on core module (not mentioned as needed step in official documentation for constriction), but the result is still the same: 10000.

Should I wait more days for better result? Or is the module dead?

10 000 is maximal value and sensor displays this value if you breathe directly to it. But that doesn’t seem like an issue here.

How did you calibrated the CO2? Did you followed some guide? Can you send me a link so I could check that? I’m not sure if we ever writen this calibration publicly. It is not secret, but very few people needed calibration so it was sent mostly by emails.

Are you using bcf-radio-co2-monitor firmware?

To calibrate you long press the button and then LED starts blinking. Keep the unit outside on the fresh air for around 40 minutes. The LEd then stops blinking. Ideally do not use the enclosure during calibration so air could better move inside the sensor.

During calibration the firmware sends over radio calibration messages, can you copy all that messages from the start calibration to the end? The best is copy all MQTT messages. The Messages tab has some limit so please make sure that all messages are there, or use Node-RED debug tab where you can also see MQTT messages, there should not be a limit of number of messages.

Hi Martin,
I have found your response in other topic here from March: CO2 calibration
Firmware is bcf-radio-co2-monitor in latest version 1.5.1
I did the calibration in my room first and now also outside and still the same result 10 000. Log is attached.

CO2 log.txt (10.1 KB)

@hub.martin Maybe the reason can be the version of the CO2 senzor 3.0.
I have also other CO2 module in the Air quality tester and here it has version 4.0 and works fine. I have tried to use bad module in Air quality tester and the same result 10 000.
The wrong one is on the right side:

Thanks for all the information. I’ll take detailed look on that and let you know later today.

Hi zdenyv,

we will replace your CO2 Module, can you send it to our address please?

U Jezu 525/4
460 01 Liberec

Sorry for trouble.