The CO and propane gas detector in my 2016 Thor Axis 24.1 has a flashing yellow fault light, CO and propane flashing red lights, a beep every 40 seconds, and a green power light. The propane tank supply valve is shut; there is no smell of propane; and the stove burners do not emit any propane gas. The RV has been sitting on my drive for 4 months on shore power. The fridge is in auto and the hot water heater is on AC power. I think the gas detector is an Atwood. Does anyone have any suggestions? Thanks.