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made a mess trying to change strainer on 2 pipe

yoadrian Member Posts: 1
Good evening everyone. New guy here from NY. I would like your opinion on the proper method to change a pump or strainer/filter on a two pipe. How do you clear the entire system of oil before cracking in to it? Went to "tune up" my system at home and had a bit of a scare after removing a strainer cover and the return line starting spitting oil out.
Thank you


  • billtwocase
    billtwocase Member Posts: 2,385
    That was always an advantage of a J pump over a mini pump. No leak back. Sometimes shutting off the oil supply line, and run the burner until the flame goes out will push the oil back to the tank. You can also work quickly and use a pump to push it back. Why a 2 pipe system? That is old school, and not necessary in most cases. FYI, never install a shut off valve inline for a return
  • Steamhead
    Steamhead Member Posts: 16,454
    If a standard single-line system won't work here, use a TigerLoop. There is no longer any need whatsoever for a two-line oil-feed system.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Coany
    Coany Member Posts: 91
    drop the oil filter
    run the burner til it locks out (checking safety at the same time)
    reset a time or two
    use a cookie sheet to catch the oil
    change that strainer
    " Do what you can, with what you have, where you are" Teddy Roosevelt
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,695
    Tank location in reference to the oil burner is important in answering this question. Is the tank in the basement, outside above ground or buried in the ground? How long are the fuel lines from the tank to the burner? If fuel continues to pour from the tank return line that exits the top of the tank and the return line terminates below the fuel level in the tank, a siphon condition exists and if you take this one step further.... what if the fuel line were to break unnoticed?

    Get rid of the return pipe ASAP and install a fuel de-aerator like the Tiger Loop mentioned above. This way you will have a shut off valve to use every time you need to change the filter

    If you can see the top of the tank and there is a union on the return line, you can loosen the fitting to break the siphon and only the fuel in the return tubing will spill (into a container or) on the floor.

    If the return line is short enough. Drop the filter and operate the pump for a 45 second safety time (time it takes for the reset button to trip) may also break the vacuum by pumping air thru the return line.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics