After many years of service a Dayton 3F271 furnace (175k BTU) broke down.
Currently my only option is an L.P. gas Rheem 15EARJR furnace.
Any comments or suggestions are very welcome.
I think you mean fuel oil , And why would it LP be your only option?
Fuel oil to some diesel to others just a play of words and BTW all smart people change from fuel oil;-)
You might want to figure out some calculations prior to converting. There are some higher efficiency fuel options now. You also have to figure in the cost of the conversion. The gas pipe has to be run and the current venting might not work for the propane. Also realize that fuel oil gives 138,700 btu per gallon and propane only gives 92,000 btu per gallon.
I was thinking he had the option of a heat pump,electric, and ground source. Oil is going to the thing of the past but still available lol.
Just do not get caught using fuel oil for diesel . 
I Knew what you were thinking just ripping your shorts and especially don’t get caught burning red diesel in your truck:shock: the fine can be in the thousands.
If you already had fuel oil stick with it!!! The reason is you are going to need just as much gas in BTU output to heat your home unless the calculations of heat lose are done. I have seen the results of converting to gas without thinking about the consequences. More moisture, hard to heat, exchangers that fail from over use just to name a few.
There are some very good condensing Oil furnaces on the Market that can provide you with efficiency just as high as gas but with the bonus of what Robert has already pointed out.
Thank you all or your comments.
Let me explain: I live in Mexico (Torreon), where winters are not very cold, so there are few local dealers that handle heating eqp.
The dealer that sold me the Dayton unit now carries only L.P. furnaces and his largest model is the 150k BTU Rheem.
I would gladly stay with Dayton if I could find a vendor.The furnace gave up after more than 20 years of use (about 300 gallons per winter season) and very little maintenance. Also, I am aware of the cost disadvantage of gas vs. fuel oil.
By the way: There is no fuel oil available as such locally. Only diesel fuel. I tought they were the same but your comments make me think they are not.
Your ok using the Diesel for heating. There is often taxes placed on Diesel that isn’t on fuel oil. They don’t want people using oil in their vehicles to by pass paying tax. There may be some additional additives in Diesel. I would think in an area like yours you should be able to get away with about 80,000 btus unless you have a large home. With out knowing the construction type of your home it’s unable to determine that.
Celso
did You check into heat pump availability in Your area ? I’m not an expert at HVAC like Charley B. but it would seem like a natural in Mexico…
LOL my shorts already have enough tears , I am just a poor farm boy
With the price of diesel and LP have you as some suggested a heat pump with small Kw strips for backup seems logical to me for your area I converted from LP to a heat pump 3 years ago and it works fine for my area which is much colder than yours. You can go on line and order your own equipment Mexico ships XXXXX into the US you should be able to ship a heat pump to your area:D:D
BTW Diesel and fuel oil are the same