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air in oil line

Steveinpa Member Posts: 1
I have an oil burner for heat and I am hoping someone has an opinion on this problem. The burner fails to ignite and I go in and bleed the line, I get some air out of it and the burner fires up. It then runs fine for 2 to 4 weeks and the problem reoccurs. It is a pump not gravity fed. At the end of last year I shut the burner off. I thought for sure that sitting for six months it would lose it's prime but not the case. I threw the switch and it fired right up. It has run for the last 2 weeks and this morning I had to go and bleed it again. I don't really have an idea on something this intermittent.


  • billtwocase
    billtwocase Member Posts: 2,385
    post pics

    of the burner, tank and location. It could be one thing, it could be many
  • icesailor
    icesailor Member Posts: 7,265
    Air in oil line:

    You describe a two pipw system. If you don't have two pipes, to and bact from the tank, you need it to be a two pipe system. Better yet, install a Tigerloop and you will only use one line and the tigerloop ends the air in the lines.
  • Gary_17
    Gary_17 Member Posts: 37
    you're creating air

    oil line restrictions[sludge, check vavles, multiple fittings,crushed lines] cause high vacume making the oil cavitate creating air in the pump. Tiger loops are not a cure-all
  • icesailor
    icesailor Member Posts: 7,265


    While it is true that no one tool or fitting is perfect for everything, a Tigerloop comes close to that catagory. Here's why.

    A Tigerloop is really a pump. Like a injector (Jet) domestic water pump. When you use a two pipe fuel system on your oil burner, you are using a similar thing when the by-pass plug is installed. The pump will deliver a set amount of vacuum (lift) in relation to to the outlet presure. The greater the outlet pressure, the less the suction. And the inverse. When you add a tigerloop, the fuel pump freely circulates the fuel through the tigerloop where it goes through a restriction, causing vacuum/suction. In a sense, it is then part of a two stage pump. But it will provide far more oil than a stand alone pump. Like the water pump, there is only one suction line. And that line is connected to a line to the tank. Usually, one line is compromised, not both. It is easy to tell which line is compromised. Switch the lines.

    Single stage oil pumps will provide "lift". If a tank is on the same level but you must go overhead with the oil line, the pump will provide "lift" to prime the pump. Just wait for it. The pump will always be under suction. If the pump seal has the slightest imperfection, it will break the vacuum and you will not have fuel to fire.

    Tigerloops have been used for years in Europe where they have a lot of wall mounted equipment and oil tanks outside. Tigerloops are used.

    If you use a Spin-On type filter, like Garber, they have a guage port for a vacuum guage. In my opinion, all other type filters are junk and help turn oil heating into a perjortive word. I always install two filters. I hear this saw about "I like to look at what has been trapped". To that I say, Look down the middle, if you can see the shiny bottom of the cannister, there isn't enough sludge in the filter to look at. If you see sludge around the outside holes in the top, there's a sample of the sludge. When using two filters, I have NEVER seen sludge in the second filter, pump strainer or nozzle strainer. Even one after four years.

    Back to the overhead. If you have a tigerloop, the overhead will prime up on its own and not require bleeding with the pump bleed screw. I have NEVER had a problem with the new Tigerloops with the black caps on top. The old ones with the plastic top with oil vapors leaking out have problems and I replace them. They will fail with a complete vacuum lock. The revised ones won't do that.

    If you don't use vacuum guages on your oil lines, you aren't doing a proper job.

  • icesailor
    icesailor Member Posts: 7,265
    Air in line:


    If a 1a30 is plugged, it is a restriction. If you had a Garber with a restriction gauge in the vacuum port, it would be in the red.

    Vacuum is a weird animal. You can pull a vacuum and suck air where you would never have a liquid weep. If you have a plugged filter, you get cavitation in a pump. Cavitation is boiling fluid. Boiling fluid is air. Air is the problem.

    30" of vacuum will crush a tank and boil your blood.

    You can have a "Jet" water pump that gets a restriction in the nozzle. The pump won't deliver the set pressure. Because the pump doesn't shut off, and doesn't have water flowing through it to cool it, it overheats. It doesn't need to get very hot but you get cavitation which sounds like marbles rolling around in the pump. The pump stops pumping water. The customer turns off the pump. You go on a service call. You take out the plug to prime the pump. The water is up to the top. You can't add water. With the plug out, you turn on the switch. The water shoots out of the pump, hits the ceiling and you. You put in the plug and turn it on. It pumps fine until it gets to the amount of pressure it will pump. You hear it "whooshing". Cavitation. Clean it out and it is almost like new. Cavitation kept the water from the vanes of the impeller and stopped the flow of water.

    A lot of guys will say that the well is "gone" and they need a new pump and well. They just need the nozzle cleaned out.

    Oil pumps do the same thing. He has a restriction alright. But if you don't put a vacuum gauge on the suction side of the pump, you aren't troubleshooting it properly. If the vacuum is normal, there is a leak. If one line is restricted, you will have high vacuum. Be careful swapping lines. If the restriction is serious and you swap lines, you may blow the pump seal. If one line is good and the other is bad, put a tigerloop on the good one. Abandon the bad one.

    Of course, this usually applies to underground tanks. Abandon the UST and put one in the house.

    Also, what I find is that if a General or Fulfo is getting sludged up, the supply and return lines are fouled. Blow them back with air. Put a pressure gauge on the return. If you have a high back pressure situation, and a high vacuum for the lift, the lines are plugged. I set my air compressor to 10# and blow them back. Blowing them into a bucket is nice. It could be plugged going into the tank.

    Try a tigerloop. You might like them.

    In Massachusetts, if you do anything to a burner, and the oil line is unprotected and under a floor, a tigerloop is the only way to go. If you go overhead, you are not required to use protected measures on the oil line. Though I always use covered tube.

    Tip: 3/8" OD covered tubing bends really nicely with a Ridgid 1'2" od lever bender. You can sure do a really neat and professional job. Sort of like one knows what the $*&k one is doing. 

    OBTW, This is what high head circulators do when you try to overcome bad piping practices in heating systems. Cavitation and air.
  • billtwocase
    billtwocase Member Posts: 2,385
    in Mass

    If the oil line is under the floor unprotected, it has to be upgraded by Sept 2011 with either a sleeved/coated line, or an OSV. A tiger loop does not remedy that law. Not sure that is what you meant Ice, but that's the way it reads. I still would like pics
  • icesailor
    icesailor Member Posts: 7,265
    In Mass, oil lines:

    Bill, for my way of thinking, a oil line under a floor WILL be replaced on any job I do or I will get a disclaimer from them stating that they will not let me replace the oil line under the floor and they WILL get another person to get code compliant. Then, a Tigerloop so I can run the covered/protected line overhead. If I can't run along the floor. Where I prefer to use 3/4" blue NMT plastic conduit. You can do some nice sharp bends without kinks. Screw them in place with one hole 3/4" HW conduit clips. Makes a nice neat install.

    OBTW, the oil company where I work will not deliver oil to ANY account that is not code compliant. They sent letters to every customer. Per requirements of their insurance underwriters. And they will also inspect it for compliance.
  • add
    add Member Posts: 94
    tank location

    dear friend before we go any further we need to know we the tank is located,inground or above ground.is it a 2 line system or a single line.is the oil burried in cement,how many fittings and so on and so forth,when was the unit serviced(oil filter replaced and canister cleaned......)
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