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Frozen fuel oil line

I work for a fuel company and do the furnace work for the fuel oil and propane furnaces.

I had a call this afternoon after a customer had run out of fuel in his 500 gal underground

tank. Fuel was delivered and he opted to bleed the line himself. I was called after he couldnt get the line bled. I took the line off the filter cup just inside the basement wall and turned the valve on, no fuel. I attempted to blow the line back with a compressed air cartridge thinking the line had gotten plugged as a result of running out of fuel. Could not get any air through the line. With such a solid plug, I'm assuming water was drawn into the line and froze. Today has been the first time the passed few days the temperature has risen above -10 or so, and -30 with the wind chill. If the line is frozen, how can one aid in thawing the line out aside from an additive?


  • icesailor
    icesailor Member Posts: 7,265
    Frozen UST line:

    The easiest way to fix it will be to wait for warmer weather. Short of that, if it is a UST and the burner is inside, it is almost always a 2-pipe system. 

    You said that you blew on a line. Was it one of two and you blew on one, the supply and not the other? The Return? If so, go back and see if you can blow through the return. I always used my portable air compressor adapted to a flared oil line. Don't set the regulator to more than 30# PSI. IMO, do not use one of those line blower outers with the little CO2 cartridges, They can develop over 1000#+ PSI if the line is obstructed and you can break the line. If you can, blow through the return line. If you can get through, leave the compressor on and connected and go listen in the vent or fill pipe and listen for the oil in the tank bubbling. The whistle may be whistling but you need to listen for it bubbling. If the return is clear and the supply is plugged, install a TigerLoop on the burner and connect it to the return or the working line.

    When you have the compressor on the line, have a way to valve it off. Leave 30# or pressure on the line and wait and watch to see if the pressure starts to fall. If it does start to fall, add more pressure, You may just have a bunch of very cold sludge blocking the pipe. Once you get the sludge moved, let it go to 60# and let it blow all the sludge out of the line.

    When you get the Tigerloop installed and the burner running, if the air doesn't stop appearing in the top in a few minutes, the line may be broken or not into the fuel in the tank.

    The tank should be running on a Tigerloop anyway. Less problems with cold and dirty fuel filters.

    The only other solutions are  Roth/Schutz type plastic tank set up outside intil it warms up in the Spring.

  • Pughie1
    Pughie1 Member Posts: 130

    Great post MR. Icesailor! Sound like you sure have been around. Brings back memories - frost bit fingers & all. All sound advice.

                                                                        John Pughe

  • icesailor
    icesailor Member Posts: 7,265
    Dirty Fingers:

    Years ago, one summer day, I was on the ferry boat going home. I struck up a conversation with a guy. He asked me what I did. I told him "Plumbing, heating, wells, pumps, oil burners, stuff like that, whatever they will pay me for". He stiffened up and asked to see my hands. I showed them to him. He looked them over and proclaimed, yes, you do work on oil. You can't get that oil soot and sludge off your hands until you give it up for a long time". He told me that he had a big oil company with installation and service in New Jersey.

    My hands are still stained. Along with my memory.
  • Pughie1
    Pughie1 Member Posts: 130

    Soot! - I hate that word!  Great story Icesalor  John
  • archibald tuttle
    archibald tuttle Member Posts: 819
    plastic tank

    i use 55 gallon plastic drums in those temp circumstances (and of course 5 gallon blitz cans with short flared line as real temp).

    i've done that grab the return although you may have to see if it is far enough into the tank to pick up but its a potential.

    I also had a line give up after air clearing it so everyone is right about being careful.

     i ran another line through the fill and overground until i could dig, because i had 500 gallons of rather expensive fluid in the tank and didn't feel like pumping it out.

    thumbs up for tiger loops

    good luck,

  • icesailor
    icesailor Member Posts: 7,265


    I don't make them up.
  • rick in Alaska
    rick in Alaska Member Posts: 1,246
    underground line

    We have very few underground tanks around here, like maybe 10, but there might also be a chance that someone put a foot valve on the supply line in the tank. I have seen it done on above ground tanks. Something to check would also be the vacuum on the line.

     Also, I always wear nitrile gloves to keep my hands out of the oil. After having cancer and being told it was because of exposure to petroleum chemicals over the years, seems like a good idea. Also, I don't like my hands to smell!

    Good luck with your problem.

  • Pughie1
    Pughie1 Member Posts: 130

    I'm from upstate New York, pretty cold country. Rick, sure wish i'd used those gloves during my career, probably would have extended it. Now all I do is help out a "friend" or two now & then + work on my own. Wouldn't think of getting the old wrenches out without them.

    By the way, do you or Icesailor (did) ever get thoughs nasty splits on the end of your fingers that won't heal? Sure don't miss those, bet we could start a new post on  home remedies & stuff for curing those.

    Years ago we used to "thin" the fuel (1/2 fuel oil & 1/2 Kero) on all outside above ground tanks. Course oil back then (60's) was only 15 cents/gal. Also,we'd usually come off the top with a duplex to keep the suction line off the bottom.  Sorry for this old man's rambling.

    John Pughe
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    Would this work?

    When I was in the radiant window business, we had the AC to DC converters that were solid state and very robust. It a person could put a binding clamp on each end of the fuel line, and then make a good and appropriately sized wire (48 VDC) connection between the ends, they have a low voltage DC pipe thawer.

    No sparks allowed….

    Just thinking out loud… Not qualified to work on oil.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • icesailor
    icesailor Member Posts: 7,265

    My experience was long before Nitrile Nitrile Gloves. When we bought our Condo in Florida in 2005, I tried to buy a box at a local auto supply places. They didn't stock them. They don't need them in Florida. Different type of petroleum product.

    I brought a box down from Massachusetts. EXTRA LARGE for my large paw. Try buying XL rubber gloves for tile at HD or Lowe's. I guess the buyers of gloves are all ladies with small hands.
  • icesailor
    icesailor Member Posts: 7,265

    Because I have issues with my feet, I slather then every morning with Eucerin cream Its thick and they used it on the old folks in the nursing home I used to do work in. It keeps my hands and fingers from becoming rasps. At least that's whet my wife says.

    SPLITS??? You don't know what Finger splits are until you open 30# to 50# of Bay Scallops for 5 months after work and not wear gloves. The digestive enzymes try to digest your fingers. I used to wear two Playtex gloves on my left hand and cut off fingers from old worn out gloves in my thumb and index finger. A few drops of juice and I was done. Cotton gloves do almost the same thing. Wear quality leather work gloves.

    Splits by the fingernail are the worst. Where's my box of 1" wide Band-Aids.
  • icesailor
    icesailor Member Posts: 7,265
    Just thinking in my head:


    Just thinking in my head but that has some merit. But for this reason. If the lines are direct buried copper, you might get some electrical path in the ground if you connected the supply and return to the respective leads. Then hopefully, the crossover is close to the tank and it heats up.

    Its my experience though that two pipe oil systems don't freeze up because when the pump is running, there can be 20 GPH running through the two lines while the burner only uses one or two. Slow flow or blockages are more to do with oil getting cold and the sludge congealing into a mass that pump vacuum can't overcome.

    If you walk into a no heat call in the cold, and the pump starts to whine like a teenager that is on restriction, you have the problem. Let the teenager out and clear the oil line.

    Both problems solved.
  • Pughie1
    Pughie1 Member Posts: 130

    Yea Ice - then you'd get a little oil on those band aids and away they'd go!

    Mark, Wish I was so smart. I used to think -" there's got to be a better way" when I was crawling around under those trailers (whops - "mobile homes") in the middle of the nite with a torch. Course they never froze in July.

  • icesailor
    icesailor Member Posts: 7,265
    Mobile Homes:

    I once heard Dolly Parton refer to them as a "Trailer House".

    I've used that ever since.

    Thank goodness they were illegal where I worked. Eve with normal houses that freeze up. No matter how many times you go there and how many times you tell them to run the water VERY SLOWLY when it is cold out and block that hole where the wind flows in, they don't want to pay for the excess water.

    And they want to pay ME to crawl around in that vermin infested rat hole with a torch to thaw pipes all insulated with heat tape that doesn't work?

    Its 79 degrees out now. Almost time to click on the AC to get rid of the hummdidity.
  • Pughie1
    Pughie1 Member Posts: 130

    Ice (that O.K.?)  Utica, NY  -  Thawing today, feels like a heat wave compared to last week, (-20*). 79* - Wow sure wish I was there.

  • SWEI
    SWEI Member Posts: 7,356

    Try Corona Hoof Dressing.
  • rick in Alaska
    rick in Alaska Member Posts: 1,246
    heat wave

    I haven't had to worry at all about a frozen line this winter. The "Polar Vortex" took all of our winter away! No snow on the ground and has been between 28 and 52 for over a month now. Very weird winter!

    P.s. for split fingers I find it is because I am not getting enough water, and because it is so dry here, also weird, I get dehydrated easily. Besides, we now have natural gas here and i am working seven days a week 12 to 14 hours, but very little oil work. Sign of the times I guess.