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old oil system

Leo_I_G Member Posts: 4
Hey, have a neighbour with an ancient oil system. Seems that it has been running with no expansion tank for years. Anyone ever heard of a situation like this?


  • Maybe there is an open tank in the attic.--NBC
  • Leo_I_G
    Leo_I_G Member Posts: 4
    NBC, did a thorough check of the whole house, nothing.
  • RobG
    RobG Member Posts: 1,850
    It's possible that the radiators are being used for expansion if they are not bled fully.
  • Robert O'Brien
    Robert O'Brien Member Posts: 3,537
    Is it an open gravity system? They have an overflow piped out of attic
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  • Leo_I_G
    Leo_I_G Member Posts: 4
    Rob G, was thinking that myself, but have never heard of it before. The old guy who use to take care of the system retired, so new guy refuses to allow it to be used until a "safety" expansion device is installed. Think I'll see if I can get the old guy's phone number and ask him about the system.

    Robert O., not sure about it being an open system. Saw nothing inside the home, was dark when I was there, so never checked outside. So if it is as you think, then I should see a discharge pipe to the outside and the make up water keeps the level correct, correct?

    Thanx guys for the insight as neighbour is older single fellow, with not much money. really appreciate this!
  • Jamie Hall
    Jamie Hall Member Posts: 22,892
    There is almost certainly an overflow or gravity expansion tank in there somewhere, and there is no reason not to keep using it. A "safety" expansion device -- I expect the young feller means a conventional expansion tank -- is quite unneeded in that case. You may have some difficulty finding the overflow or gravity tank, though -- but it will be in the attic somewhere. If it is an overflow, it may not go outside -- it may be connected to a plumbing vent pipe. May take a good bit of sleuthing.

    That said, the young feller does sort of have a point: there really should be a temperature and pressure relief valve on the system. Look around and see if you can find one. If not... really should put one on. If it's an open system, it's not so much for the pressure (it will need to be set high enough -- at least 15 pounds) but for overtemperature.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • icesailor
    icesailor Member Posts: 7,265
    I once found one drilled in to a 4" soil stack in an attic. An old dead guy told me about one that was drilled through the roof and the overflow went on the roof shingles.

    If the gauge on the left is the pressure and the one on the right is just temperature, it should be marked for the height and filled accordingly. Others just had the overflow run back into the cellar so if you forgot to stop filling, it just overflowed somewhere near where you were standing.

    That's probably been working like that since before I was born. Why mess with success.
  • kcopp
    kcopp Member Posts: 4,387
    The house I grew up in had a gravity hot water system. Expansion tank was in the master bedroom closet. The overflow did run back down into the basement and into the 4" cast building drain. Your boiler actually is an old coal fired unit that was converted to oil. More than likely it has a non flame retention oil gun and a stack switch to regulate the boiler temp. There are A LoT more efficient options out there. If the new service guy doesn't understand the set up he should find out more from someone who does. Messing around w the piping on that old boiler could run into a real pandoras box.
  • FranklinD
    FranklinD Member Posts: 399
    That reminds me of when they replaced the coal fired monster in my mom's 1890 house. They had a heckuva time finding the expansion tank until my dad got home (this would be 19 years ago...how time flies).

    The house has a finished 3rd floor ('attic'), all done up in hardwood, scrolled trim, and plaster. There is one radiator up there in the hallway, a 24 section, 38" tall American Radiator Corp monster. They failed to notice a Tee in the supply line, right at the floor, that disappeared into the wall. On the other side, in a long dark closet, there was nothing...except a sight glass protruding from the plaster wall. They buried the tank in the wall.

    After they opened up part of the wall, they found a pipe from the top of the tank, which tee'd up to the roof (as a vent), then ran another 2' over, where it tee'd into the soil stack which was conveniently in the same wall.

    I always thought that was pretty cool. My folks had them leave it all there (after the Tee at the radiator was plugged) for historical reasons. I have pictures somewhere around here I should really scan. Or take some pictures the next time I'm over there.
    Ford Master Technician, "Tinkerer of Terror"
    Police & Fire Equipment Lead Mechanic, NW WI
    Lover of Old Homes & Gravity Hot Water Systems
  • RobG
    RobG Member Posts: 1,850
    And it is allways possible that the system has been "knuckleheaded" throughout its many years of loyal service.
  • kcopp
    kcopp Member Posts: 4,387
    Gravity hot water is/ was a cool set up. This is one of the first things I read about on the original "wall" Dan had a VERY informative article in "How Come". They can be very tricky!