Carbon Monoxide Sensor DIGOO DG-HOSA Smart 433MHz

I have this one from AliExpress too.

I use it in a room with a pallet heating boiler. Even when the boiler is not active for a long time and windows are open (there should be no extra CO levels) the sensor is beeping from time to time. It is a single beep every few minutes. No regular pattern

I was thinking that it is a warning for higher CO levels but I am not sure. I do not use a battery but an adjustable voltage adapter from 12V to 9V so I do not need to replace batteries. Anyone using this one?

My mistake.

After replacing the cable I’ve wired the positive terminal to 5V instead of 12V. So the Sensor was getting like 3.7 V and beeping as low battery alert.

And now you have it working properly ?