Furnace and thermostat issue?

What I experienced when I had relatives with that insisted on closing the bedroom door is it heated up in the bedroom and then the thermostat would shut off leaving the front part of the coach cold. Duct work or not where ever the thermostat is is where it gets its instructions on what to do. Seal the bedroom up with a closed door and it is going to reach that temp set quickly and shut off. I froze my butt off that weekend sleeping on the couch up front. :R

I leave all doors open for air circulation unless I need to close a door for privacy.

Don't make this complicated....
just do the same thing you do at home.
No need to close doors or keep them open, no need to put a bunch of thermometers all over you rig....go camping and relax. \\If it is too warm, or too cold, adjust the thermostat accordingly.

If you place some thermometers around your RV while the furnace is operating, you should get a fairly good look at your heating situation and how the actual temps relate to the thermostat setting. I've found the small "keychain" sized thermometers are easy to position.

I have two discharge registers above the entry stairs, one is adjustable and one is not, if I leave the adjustable register open, I get much less air in the rest of our rig. If I close the register I get a lot more air to bath and bedroom. The registers are available from most dealers and parts outfit. Buy one that is adjustable and install it where ever you would like to reduce flow. I don't think leaving the door open will have any effect on amount of propane used and the wall we eventually reach ambient temp and eliminate any effect it might have on the stat.

While this doesn't really apply to your question, the thermostat in our rig is above one of the dinette seats and if one of us is setting there, the thermostat reads about 70. Because the stat is left at 65 most of the time, the heater doesn't come on until we go to bed.

Furnace discharges thru ducts.
Ducts go to bedroom, bathroom, kitchen, living room and possibly to basement area/underbelly area

Most OEM registers are not adjustable because furnace NEEDS the correct air flow (discharge/return) to properly function.

Closing door will not affect how long furnace runs.
Warm air will still go to closed off area and cooler air will return via under door.

So close the door or don't close the door.........same/same