Whereabouts in the caravan do you place your carbon monoxide detector, mine has been by the front door next to the smoke alarm, is that the best place?
Our fire detector was near the door and had a noise suppression button, so if it squarked when grilling etc it would be suppressed for a few minutes . Carbon monoxide detector was mounted towards bedroom end on wardrobe wall about six foot above caravan floor.CO is almost the same weight as air so it does not sink to the floor, Eego you can fit it anywhere convenient.
However your fire alarm is likely to be a standard unit that detects heat and smoke. Consider replacing it with either a heat only or heat plus delayed smoke so that it doesn't keep going off if the toast gets a bit overheated.