ICC-500T reads 3500ppm+ ambient CO2! Only a few months old, is sensor shot?

CO2 reading is waay off! Any ideas why?

My reads next to 0 at ambient… :frowning:

Did you solved your problem? I tried to push both up and down button together for more then 5 sec, than you come to a hidden menue. Here you can adjust time in the first line and a value in the second line. Fabric-setting is 3 min. in toppline and the value 400 in secondline. I have set the value to 850 and let it do its work for the 3 minutes, and now it seems to work …