Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Encasing underground oil suction & return lines in 4" PVC pipe

belham Member Posts: 32
edited February 2018 in Oil Heating
Hi again all,

Keep narrowing down everything I am going to do when replacing suction & return lines on my oil burner setup here. Have a question: currently, from my underground tank, the sheathed suction & return lines are just laid thru dirt until they reach & go through the house basement utility room wall.

Is there any problem, when I lay new lines in the next few months, if I lay 4" pvc piping from the manhole covered brick wall (of my underground tank) to & thru the house wall? The purpose would be to put inside this 4" pvc both the new suction & return lines, and if anything ever happens in the future, I can easily remove & slide the lines out. There's plenty of horizontal room inside the house utility room to lay out perfectly straight 8-10' sections of new sheathed oil lines & slide them back thru the pvc to the underground oil tank. I thought, that way, if any future pipe clogging, restricting and/or failures occur, I could easily replace my complete oil burner setup lines with brand new---all "without" having to dig up anything (house and/or foundation-wise). (Note: the distance/length of this 4" pvc would be 8' from underground tank to & thru the house wall.)

What I am worried about is might this be a bad idea, in that the oil lines will just be lying inside this 4" diameter, 8 ft stretch of pvc pipe?? I mean, they wouldn't be secured inside the pvc for that 8' of length. Would they be at risk of sloshing around, or moving back & forth slightly during burner cycling, and thus prone to early fatiguing and failing? Once they reach inside the house, of course they would be secured as they travel another 13-14 ft along the wall to the burner. And also, back at the underground tank, they would be secured at the top of the underground tank plus I can make a DIY buttress at the PVC pipe opening there.

Thank you for any advice. Here's a pic of what I am thinking (of course, I would slightly incline the pvc up towards the house to prevent fluid, water or gas, from running that direction, and I additionally would make some sort of flap seal (or maybe use instant styrofoam sprayed in the opening) to somewhat seal up the opening where the pvc pipe & lines enter the house):


  • Jamie Hall
    Jamie Hall Member Posts: 21,094
    That's a very good idea. For yet further reassurance, slope the PVC slightly toward the house -- that way if there ever was a leak you'd know about it.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,128
    One pipe.
  • Grallert
    Grallert Member Posts: 563
    Do it! It's a good idea. Seal the ends so you don't get any odors in the cellar when you get a fuel delivery. And If it were me? sure run two fuel lines if you want but i'd only use one and use you tiger loop. And slope it as @Jamie Hall said. Good plan.
  • leonz
    leonz Member Posts: 777
    The first thing I have to ask is how long has that tank been in the ground???? That is something that I would want to have examined first.

    You could have a tank shell failure and not know it until it gets into you well water if you use well water PLUS the liability is huge for you and a future owner that could come back against you and added to that the possible(most likely the inability to sell the home with the tank in the ground.

    Lots of work before you do it.

    L Thiesen
  • belham
    belham Member Posts: 32
    edited February 2018
    Thank you, guys, for the feedback. Tonight added a 3 meter, 10cm (4") ID pvc pipe to the parts pile for when I do this job. Was uncertain, but am now definitely going to install the pvc pipe when digging up everything.

    The mini home depot-like place also had some cap joiners for the ends of the 10cm pipe, that I can modify for the suction & return lines. Thus it will be easy to both put them on & remove (if ever needed), while also keeping out crud & looking professional.

    And, @jamie, gracias for the tip about inclining the pipe towards the house so any leak would show up. I was thinking inclining the pvc pipe the other direction in case there was a Noah's Great Flood or something. Never thought about doing it the other way (like you suggest) would be a way to let me constantly know if a line, either suction and/or return, ever developed a 'leak'!

    Thanks again all!

    P.S. Guys, in the villages around where I live, I've been in about 20 different oil burner homes (from $200k homes up to near $800K homes) over the past few weeks since my nasty vacuum-suction line problems started. Old houses up to new houses. Not one, not a single one of them, were setup as 'single-line' (here we say 'strand', or "zwei zeilen") oil burner systems. They are all, even the newest house I saw last night (built last year), setup as a two-line burner system. This newest house has an equivalent 2000 U.S. gallon underground tank that is sealed in its own concrete and specially lined pit, and built with a manhole cover (like what I've been showing you all on mine...though I don't think I have the new lining). Some of the older houses I've seen have had their oil burner 2-line setups running for decades, and they are still using the same burner (among others, Buderus, Viessman and Weishaupt seem to be most popular..but there are over 120 oil burner manufactuers in Europe, commerical + home). Anyhow, they've been using the same burner for decades with zero problems. It's amazing, and the stuff still looks like new. Of course all these guys fanatically maintain their setups, but still...... Makes one wonder about this single-line setup & using the Swedish-developed Tigerloop phenom (you all did know the TL technology was developed in Europe, right?). Last night the guy at the new house said to me that any tigerloop-device on any home oil burner system is either a sign of a bad setup and/or a lazy technician. It's hard to tell with the Germans/French, but I am pretty sure he was kidding. At least I hope, lol.
    EBEBRATT-Ed Member Posts: 13,426
    edited February 2018
    Don't know what Danfoss pumps recommend but you can google both "Suntec" & "Webster" fuel oil pumps. Suntec shows both single and two pipe systems and gives the maximum vacuum recommendation for each system. they don't recommend a system and leave it to the designer. Webster says that for a buried tank with lift a 2 pipe system is recommended. I have always thought of a Tiger loop as a band aid. I have no doubt that they can work and save costly excavation for a while. I prefer to have tight oil lines with no leaks
  • belham
    belham Member Posts: 32
    edited February 2018
    @Ed...yeah, i hear ya. The more I ask, the more I read the German and French forums, the more I realize in Europe, they actually do consider the TL devices as bandaids for poorly setup systems.

    As far Danfoss and Suntec, the fuel pump makers: you want to know how they send out (or sell) all their pumps here? They are sent out from the factory setup as "two-strand" or I mean "two-line" systems. When I asked the Danfoss engineering guy, he said, in rough translation, "...there's a reason we send them out that way..."

    I got the hint loud & clear. Plus talking to you helped. I know TL devices have their purpose & place, but seeing how Europe has been doing oil burners a helluva a lot longer than we in the U.S., especially the Germans & French, I think what they practice is worth considering. Anyhow, when I do the whole digup here, I am definitely sticking with the two pipe system. On my house the two-pipe worked too damn long (nearly 15 years) with nary a squeak...until now, with this vacuum and/or possible air getting-in thing. And that 15 years was with just general maintenance from me (filter cleanings, nozzle changing, boiler scrubbing/cleaning, chimney checks & cleaning) and also having a burner guy come out & run his Testo every year while actually never adjusting anything except his mouth as he says: "Alles ist gut!" (all readings are great, giving me the printouts and showing me the Testo results). I always laugh, and say, yeah, whatever, now please give me the darn Certification Paper, lol ;-)

    EBEBRATT-Ed Member Posts: 13,426
    @belham see the attached from Danfoss. Clearly they recommend a 2 pipe system if you have any lift
  • Leonard
    Leonard Member Posts: 903
    edited February 2018
    I'ld HEAVILY seal the 4inch pipe to the wall and seal off the oil tubing to the 4 inch pipe so that in case your area floods you won't have water pouring into your cellar. Easier to seal it now when it's dry, will never seal it when it's wet.

    Here in NH the freeze line is 3ft .So if your 4 inch pipe is above your freeze line then it can move around and maybe crack during freeze/thaw cycles.

    These days double walled tanks are standard. I'ld also worry about that underground tank leaking. If it leaks the fuel should go straight down to water table ,then float "downhill" thru neighbor's yards. In town here we had a church with a 1000 gal tank that leaked . It contaminated the whole block. Oder was noticeable in test well ~ 800 ft away. Serious liability risk $$$$$$$ ,can wipe you out.