Gas furnace question

I'm looking to replace an old oil furnace on a rural property with a propane furnace. I intend to do it myself. Since the property is just a hunting cottage I am not looking to spend a lot. I am actually looking for a used furnace if I can get one. My question is whether gas furnaces are specifically made for natural gas or propane, or are they all the same and just need a different orfice(s) intalled to match the type of gas used? Anyone know?

Thanks

Jimw

is google broken today?

I bought a new one and watched as the tech did a changeover to propane. While some may be shipped with the changeover already installed, they are essentially the same unit. Too bad I didn't know you a couple of years ago, I had 2 complete propane furnaces I scrapped out, one was in really good shape, I just couldn't imagine much of a market for them. I'd have gladly have given them away.

Usually different orifices.

You breath through one and you...... Never mind.

TDD

And you go to the other orifice in the morning. "Honey, I'll be at the orifice, if anyone needs me".

Double entendre intentional.

Any old port in a storm...

TDD beat me to the reply. Another possibility of flue gas not venting properly even with the vent pipe clean and intact is that the room is in a negative pressure and the gases are being sucked out of the draft diverter. The air going up the vent pipe has to be replaced by outside air somehow. Usually, especially with a small furnace like this one, enough air leakage occurs naturally. However, a fireplace or anything else that pulls air out of the house can cause a negative. Larry

Years ago I lived in a house with a fireplace and every time the bathroom vent was turned on, we smelled the odor of burning wood. The bathroom vent was pulling air back down the chimney into the house. Same thing can happen with a clothes dryer that is vented to the outside.

TDD