What is needed is a dual chamber detector that will detect CO and smoke from a slow smoldering fire such as may start in a R/V because of electrical fires and fast burning smokeless fires. It will fit where your old one was.
After a lot of research and talking to Kidde, they assured me that this one would work in a home and also A RV,there is no difference.
This is what I found.
A Kidde KN-COSM-XTR-BA Nighthawk
That seemed to be best suited for this kind of application.
Like This They now can be bought at Home Depot, also At Amazon.
Home DepotAmazon I suggest you read all the info and make your decision on this but I replaced the ones in my Class C with this one.They are rated for 10 years
and most are only rated for 5,If your RV is older than 5 years old and they haven't been changed they are most likely no good. Mine needed to be replaced so this was a good deal for me, I had a hard wired one and I chucked it for the battery powered ones, they can be checked before each trip by pushing the test button in the center of the unit.
2006 TIOGA 26Q CHEVY 6.0 WORKHORSE VORTECFormer El Monte RV RentalRetired Teamster Local 692Buying A Rental Class C