Q12: What can I do to test the CO shutoff feature and make sure it's working?
A: You should never run your generator in an enclosed or unsafe location in an attempt to test CO Shield. If CO Shield experiences a fault and no longer provides protection, the generator will shut off automatically and the yellow LED light will blink for at least five (5) minutes to notify you of the fault. If this should happen, please call our Technical Support Team at 1-877-338-0999 for repair solutions. In this situation, the generator can be restarted but will continue to shut off.
See https://www.championpowerequipment.com/generator-safety/how-to-keep-your-generator-safe/ for more information on generator safety.