Replacing A Old Furnace With A Diesel Heater?

Where are you going to store the Diesel fuel?

Will you get rid of all the other propane devices?

I think any combustion heater can create a CO issue when the heat exchanger leaks exhaust fumes into the heated air, no matter where it is installed. Or when the exhaust gases somehow manage to get inside the camper. Whatever you do, make sure you have a working CO alarm.

I had a CO alarm go off once.

Apparently this is what happened: We were parked with the water heater side of the camper into a steady wind. There was a small air leak where the propane line exits the camper and is connected to the water heater. There was a rubber grommet, but it didn't seal the opening airtight. The water heater was running when the furnace started its cycle. Apparently the furnace created enough of a vacuum in the cabinet where both appliances live to suck w/h exhaust fumes into the camper. They didn't dissipate fast enough on the outside because of the constant wind, which probably also did not help with a clean burn.. Eventually, the CO alarm went off.

We shut everything off and vented the camper, no harm done. Leak sealed with some butyl rubber. Future parking takes wind into account.