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has this Buderus Logalux LT been properly grounded? (pics)

timo888 Member Posts: 137
I am concerned that the Logalux LT tank has not been properly grounded. The green wire coming from the electric panel terminates in the on/off switch box on top of the oil burner, attached to a three-prong outlet there, and does not pigtail to the box and never leaves the box. I removed the front cover to reveal the cleanout plate. Although the anode is connected to a short grounding wire which is fastened to one of the cleanout plate's hex bolts, it looks as though the tank itself may not be grounded. Is the unlabeled wire I've marked in the attached Buderus diagram supposed to be the ground wire that goes back to the electrical panel? Does my tank need to have a ground wire attached to the Test Clip? Would that wire come through the pipe I've circled in green? Thanks


  • Charlie from wmass
    Charlie from wmass Member Posts: 4,311
    Item 4 is a sensor

    It is not a ground.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • timo888
    timo888 Member Posts: 137
    ground wire needed if dielectric unions are used?

    OK. I see now that the wire that passes through the insulation cutout is for a Logamatic sensor. Thanks.

    I see that the anode is connected by a short ground wire to a bolt on the cleanout plate. But how does the tank itself get grounded? Does another ground wire need to be connected to the cleanout plate and clamped to the cold water supply line? Or would that be necessary only if dielectric unions are placed on the inlet and outlet connections?
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,840
    The anode doesn't depend on a ground to be effective...

    Some of their newer tanks that have the charged anode probably should have a ground, just as a matter of safety, but the anode will protect the tank regardless of whether a ground is present or not. The oxygen is looking for SOMETHING to eat, and if it has a choice of a nice soft mushy magnesium or aluminum anode, versus a hard steel tank, it WILL go after the anode. Once that anode is gone, then it turns to the next tastier treat, that being your steel tank ;-(

    Follow the manufacturers instructions to be safe.

    Even though there may not be an earth grounded connection, the tank is most probably fairly well grounded through its other connections to the systems.

    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.
  • RobbieDo
    RobbieDo Member Posts: 131
    Last pic

    You posted this on the other controls thread. Your outlet isn't wired right, check what I wrote on your other thread.
  • timo888
    timo888 Member Posts: 137
    grounding to the copper cold-water supply

    Thanks for the reply. I am trying to find something detailed on the Buderus instructions regarding grounding, but all the manual says is that it's important that the tank be properly grounded.

    So what I've done is to clamp a 12-gauge stranded copper to the copper cold-water line, run it down through the insulation cutout, where it is held to the sensor clamp with the butterfly nut. The anode is grounded to one of the bolts on the cleanout plate.
  • meplumber
    meplumber Member Posts: 678
    I think that you may be a little confused.

    They wire in question in your picture is the DHW sensor wire for the Logamatic control.  The ground wire that Buderus speaks of in the literature is the little wire that goes to the bolt on the face plate.  The anode rod is attached to the face plate and microamp readings can be taken to determine anode rod life.

    If the little wire is connected from the faceplate bolt to the anode rod as shown then you are fine.  Again, the wire that you question would be used if you had a Buderus 2107  or 2109 Logamatic control that sensed your hot water temperature.
  • timo888
    timo888 Member Posts: 137
    edited April 2011
    anode ground independent of electrical system

    Thanks for the reply. My concern was that the ground from the electrical wiring had to be passed through to the tank in order for the anode grounding wire to work. (In other words, my worry was that if the tank itself wasn't grounded, then attaching the anode ground wire to the bolt on the cleanout plate wouldn't do anything.) The oil company has the green wire from the incoming BX connector attached to the neutral of the outlet rather than to the grounding prong on the outlet, and no green wire exits the box; all of the controls including the aquastat are ungrounded. But I gather they don't need to be.
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