How long will furnace oil keep for?

[hemlock]

Hello,
Went outside yesterday evening to get an armload of wood and noticed my oil tank. It as had the same 3/4 tank of oil in it for a couple of years now. It got me to wondering how long furnace oil keeps for. Anyone have any idea? Thanks.

 

[Fsappo]

stays pretty good in the ground. Never heard of oil goin bad alone, but tanks can build up crap. Or rust

 

[xjcamaro89]

Well, I work for a home heat company. If its a above ground tank with #2 fuel in it and no treatment. The worst that could happen is you get water in it from the condensation in the tank from the swing in high to low temperatures. Is it alot? No, but over time and never getting it filled or using it you might get a build up of water in the tank. It could also sludge up a bit, but they make a bottle of treatment to add to it to remove the sludge. Maybe get a bottle of that some time and pour it in and if possible get a stick that you can stick down in and give it a swirl.

You plan on ever using it? If not, you might want to advertise it for sale. im sure if you knock a little off the going rate for oil you wont have a problem getting rid of it.

 

[velvetfoot]

I've heard of biological problems. I think they have stuff for that. Is that what the sludge is?

 

[xjcamaro89]

Ya, the fuel sort of seperates, or in colder temps in a above ground outside tank the fuel gels (if not treated) #2 fuel is essentially just diesel fuel. So you know what old fuel will do to vehicle engines. You run into that same problem with furnace fuel.

 

[maverick06]

I have the same concern, so i did the best I could do to fix it.

I have a 250 gal tank in the basement with about 120 gal left in it, and i burn 30 gal/year.

In order to minimize any problems I added diesel biocide, something like this one, not sure if it was the same exact product:
http://www.amazon.com/Racor-Diesel-Biocide-16Oz/dp/B002MBN4S0

and I added a stabilizer to keep the fuel clean(er). power service clear-diesel http://www.roadgiant.com/powerservi...mfuelandtankcleaner-treatsupto125gallons.aspx

I dont know if the above were a good idea. But I figure the biocide will keep anything from growing and the clear diesel will minimize water related problems with the fuel and help stabilize it.

Since I only burn 30 gallons a year, I think I will now just use a few 5 gallon cans and buy off road diesel and fill the tank with it. This way i can keep about 60 gallons in the tank (2 years worth) and have the fuel not sit there as long. There is more room then for condensation, but I think that stale fuel is a worse problem! I dont want to pay to dispose of 200+g of fuel.

Not sure if that is good advice, but it is what i did!