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Size of underground #2 fuel oil tank

EdEd Member Posts: 284
where is the vent standpipe? Usually the vent & fill enter/exit the top of the tank about 6" from the ends.
Note: if the tank is that old, it may have to be replaced with an above ground tank - insurance reasons.


  • ombreombre Member Posts: 32
    Size of underground #2 fuel oil tank?

    Dimension from top to bottom===33 inches. Done by stick measurement at fill entrance---allowing for fill stand pipe.

    Don't know length of tank. (It is after all underground and been that way since 1965)

    Tank was installed when the house was new-----about 1965.

    Been a very long time since I serviced gun fired oil burners. I do remember that 100 gallon (above ground) and 300 gallon (below ground) were most common 40 or so years ago. Not sure about in-between sizes then or now.

    From the only measurement I can easily do==33 inch diameter-------what is the size of this underground tank in gallons? Or your best guess?
  • ombreombre Member Posts: 32

    All I had to measure with was a standard measuring tape to tell how far down the standpipe was.-------hooked the end of the tape on the pipe and measured. Discounting that measurement from above ground---- I came up with a 33 inch diameter tank. Length unknown.

    Of course the standpipe could have gone down farther into the tank than to be right at the top of it. Can't think of a good reason why though----- give or take a half inch or so.
  • FRANKFRANK Member Posts: 80

    Most 550 gal o.t.s are 48" dia. A standard 275 on the flat is 26/27. Can't you fill 'er up, then run it dry and fill up again? Thats the positive way.
  • LIBOBLIBOB Member Posts: 23

    Only sizes I'm familiar with:

    275 gallon tanks - 26" & 42" 550 tank -48" 1000 gallon - 48" &64" You may want to check your measurements again.
  • ombreombre Member Posts: 32

    I am a little worried about this underground tank due to its age. Could be a slow leaker. Would help to know to determine measurement wise.

    It is my daughter's 40 year old gun fired oil furnace which seems to work well ----but I do try to pay attention to things that may go wrong--which includes possible problems with a very old underground tank.

    I don't even know and she doesn't know how big the tank is.

    Would like to determine that.

    I think that 300 gallon tanks underground were pretty normal. Is this a 300 gallon tank?-------based on a 33 inch measured diameter?

    Of course we could have it filled and find out that way ----but with the soaring cost of fuel oil, I would like to find out the size of the tank a cheaper way.

    Just asking for your best questimates here. 33 inch diameter, unknown length-----what is the capacity in gallons of this tank?
  • ombreombre Member Posts: 32

    Frank seems to have it pretty close, given the very innacurate dimesions I gave.

    So pretty much close to a 300 gallon tank, Eh?

    My daughter can't afford it, and I would have it filled if I could afford it but--------I don't have the money to fill a 300 gallon tank with #2 fuel oil right now.

    Very worried about it being a 40 year old slow leaker. Money wasted and environment damaged.
  • EricjeeperEricjeeper Member Posts: 167
    put 150 gallons into it..

    and see if it brings it to the 16.5 inch mark on the tape.
  • Tom R.Tom R. Member Posts: 139

    Could youra tank be 36"? Still need the length to find the capacity. 550 gal. = 48"dia. Same dia. for 1050 gal. If your house was built along with some others by the same builder, try the neighbors for info. Also might try the code enforcement office or buildings dept. in your jurisdiction. They may have plans submitted for it. In any event, a 40+ year old tank probably will fail a test and should be replaced or removed.
  • ombreombre Member Posts: 32

    One problem is that I live in the Tampa bay area and she lives in Jacksonville, and I only get up there infrequently.

    Was up there over Christmas and the 80 gallons I had put in at Thanksgiving seemed to be gone. 80 gallons of fuel oil with today's prices is a lot of money.

    Pretty sure it was gone (out of fuel oil) was the reason the furnace would barely fire up and would trip on safety.

    Measured 6 inches on the stick. Seems a little high to be out of fuel oil-------but depends on where the pick up tube is placed. After all you don't want to suck in water.

    6 inches does seem a little high though.

    I live 200 miles from my daughter---so infrequent diagnosis gets to be a little difficult. This is after all Floriduh, so nobody is going to freeze to death, but I do worry about my grandaughter.
  • ombreombre Member Posts: 32

    Ordered another 80 gallons of #2 for my daughter. Showed her how to "stick the tank". Will find out soon enough whether the tank is leaking.
  • ombreombre Member Posts: 32

    I would like to thank you all for all your help.

    Did not realize that there were so many different configurations of underground tanks.

    In my personal experience many many years ago in Florida---300 gallon tanks underground were the norm.

    But looks like the only way to tell for certain what size tank she has will be to fill the tank.

    Maybe someday.

    Again thanks.
  • burnermanburnerman Member Posts: 296

    i delivered oil for 17 years the way i find out is to stick before and after then figure it out we have charts e
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