If you have an oil furnace and are considering converting it to propane, there are a few things you should know. First, propane is a more expensive fuel than oil, so you will see an increase in your energy bills. However, propane is also a cleaner burning fuel than oil, so you may offset some of the increased costs with lower maintenance and repair bills. In terms of the actual conversion process, it will cost between $500 and $2000 to convert your oil furnace to propane. The exact cost will depend on the size and type of furnace you have as well as any modifications that need to be made to your home's ductwork or gas lines.