when I came into shop this morning both carbon monoxide alarms were going off in camper. The camper is pluged in and gas is turned off. any ideas what could set off?
Just because it's plugged in does not mean the converter is working correctly and providing power to the detectors. They could be pulling off a slowly-draining battery.
About the only way I can think of to test for CO is to put a canary in the camper and see if it dies.