I live in a small apartment so I check the readings often. When the a/c is on the co2 levels rise so we leave a window cracked. This has seemed to be working to keep the levels reasonable. Today I checked and the co2 levels all of a sudden went to 4376. No ramp up, just instantly BAM! Could this be a component failure? I’m pretty sure this cannot be accurate…especially as there is no one home.
The CO2 could get off for example when the monitor is transported or exposed to shocks or vibrations. Could the monitor have fallen down on the floor?
Which hardware and firmware version are you using?
The newer ones support forced CO2 calibration and that should fix it. Or wait a week for the automatic baseline calibration to kick in.
We have a new kitten so, yes, it definitely could have been knocked down. 
Looking at the graph it seems like the usual curve…just stepped up 3000 points. Not sure which version I have, I got it last December…I’ll just keep an eye on it. Thanks!
I do see an option for “CO2 Calibration Requested”
Yes you can try that but make sure the monitor is exposed to ambient CO2 levels first for at least 10 minutes.
Put it next to an open window or outside should do the trick.