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"Interesting" arrangement

wbyf Member Posts: 2
edited December 2023 in Oil Heating
I'm far from an oil guy but sometimes..

I do some work for a fella who buys, ahem, "not so pretty" houses to flip. Not a lot of work mind you, 'cause I'm not usually "in the budget" but sometimes he ain't got much choice but to call when he needs something done beyond what his usual suspects can do. I don't do a significant amount of oil though I do have enough tools and knowledge to be dangerous. Most of my work is LP and natural gas but I'm not one to turn down work.

Anyways.. This house was previously owned by a guy who spent a lot of time and effort rather than money and did most everything himself. There were apparently 3 oil tanks with one being outside and two in the basement but the outdoor tank has since been removed.

At this point, there are two oil tanks in the basement with duplex bushings but one tank has both ports plugged. It appears the supply previously came from one tank and the return went to the other but both 3/8 lines go to one tank now (at least he used a flare union and not a compression union!).

It appears they tapped a hole in a couple pipe plugs and made their own single-pipe version of the duplex fittings. I assume this line may dip into at least one of the tanks and is meant to act as an equalizer. Unfortunately, I neglected to look underneath the tanks to see if there was any piping on the bottom hiding in the back against the wall. That said, the tanks don't appear to be equalizing as one shows about 1/2 full while the other is about 1/4 full.

The house-flipper relayed that according the previous homeowner, occasionally the system "gets an air pocket" and that a Tigerloop would "fix it right up". There is of course a desire to fix this without spending money.

My first instinct is to drop the ball and walk away.

Counter to my better judgement, I'm considering quoting to run a new 3/8" line to each tank, tee them together into a General filter, run overhead to the boiler to a Tigerloop Ultra and call it a day. I'd prefer to eliminate the second tank just to remove the extra potential for headaches but seeing as it is already there, I doubt they'll want to pay to remove it or have to answer questions of why it's orphaned when they go to sell. My preference is bottom feeding from the tanks as it's what I'm familiar with but I'm also not particularly interested in playing with fittings in the bottom of an unknown condition, 1/4+ full oil tank.


  • Big Ed_4
    Big Ed_4 Member Posts: 2,710
    edited December 2023
    The correct way is installing an equalizing line . Which is a 1/2" line connecting between the two bottom taps. I would add a drain port to remove water .

    They are using that single 3/8" top feed line between them as an equalizer ...
    I have enough experience to know , that I dont know it all
    EBEBRATT-Ed Member Posts: 15,345
    The line on top will equalize the tanks believe it or not IF it is completely full of oil and has no air in it. Since there is no way to do that you have 2 choices (other than walk away)

    Bottom connect the two tanks which can be done with a vacuum cleaner to pull a vac on the tanks 1 at a time and installing valves and nipples on the bottom of each tank.

    Slightly risky and not much fun.

    If it was me I would tee both suction lines together coming out of the top of both tanks When the burner pulls a vacuum the tanks will equalize. Keep it two pipe and forget the tiger loop and it will work as long as the suction line is tight. Tee the return to both tanks as well
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,600

    My advice is to do it right or don't do it at all. Get paid what you need to get. You can quote about 4 hours of labor and all the necessary parts to do the 1/2" ID copper connection to the tank bottom fittings. Use the necessary valves at the bottom of each tank, and route the copper connector under the tanks out of the way, so as not to get damaged by unsuspecting items getting stored near the tanks.

    I would do the vacuum cleaner idea to pull a negative pressure in the tank, so when you remove the bottom plug, the valve can be swapped out in short order. You should spill no oil that way. Get that done on both tanks (if they do not already have valves on the bottom) then you can pipe the two tanks together with a Tee fitting and a drain valve to remove water during the annual maintenance. Since you are going that far, You might as well just put an oil filter on that Tee and put the fuel supply line on that bottom feed filter.

    For a little more money, get rid of the overhead fuel lines. Then remove the bypass plug in the fuel pump and you don't need a return line. Run the fuel line across the floor, around the perimeter to solve any overhead line issues. Chances are you will get the new owner as an annual maintenance customer. My son is doing annual maintenance on a bunch of oil heaters and getting a little extra cash as a side hustle. When he is not at his day job welding awning frames
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • wbyf
    wbyf Member Posts: 2
    edited December 2023
    I prefer the bottom tank connections just for (my perception of) simplicity but I lean towards one pipe even off the top as it doesn't make much sense to me to run two pipe and excessively re-circulate and aerate the oil by dropping it back into the tank. Biggest hurdles with bottom connections are that I am unsure of which direction the tanks are facing and how much crud is accumulated in the bottom of the tanks.

    I don't trust anything that the fella did so no matter what the slate is getting cleaned and we're starting from the beginning. That said, this is a "customer is always right" situation. They specifically asked for a Tigerloop so I'm goin' to quote a Tigerloop as an option. Whether that is what they decide to do is entirely up to them.

    I don't see a problem with a one-pipe overhead system without a Tigerloop so long as the system is tight, though the potential for a homeowner to run the tank(s) low and lose prime tends to make the Tigerloop look more attractive to prevent future issues.

    Seems to be that I knew what I thought I knew but I didn't know that I knew it, ya know?

    Anyways, I'm going to stop back there today and look at a few things I neglected to look at yesterday. I'll post updates as they come.