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wiring of oil furnace on/off switch

Not sure this is the right sub-forum to ask. Since it has to do with electrical, Controls seemed a reasonable place to ask.

The oil company installed my oil boiler and water heater (Buderus Logano and Logalux LT). I know only a little about electrical wiring but it seems to me the unit may not be properly grounded. Certainly the green wire is not attached to the green screws of the switch or the outlet, or to the box itself. Also, I don't see the green wire passing through to the little control box. Only black and white wires go to it. I've attached some pictures. And the green wires near the controls are wrapped like vines around the other wires and are clearly not connected.

The Logalux manual says to make sure the unit is properly grounded or tank damage can occur. How is the ground passed through from the on-off switch down to the tank if if the green wire isn't passed through to the little control box?



  • Matthew Grallert
    Matthew Grallert Member Posts: 109
    green wire bites

    Am I seeing that right?  It looks like that ground wire in the first two photos is made to the outlet on the service switch?!  Can't tell if it's neutral or line.  That will bite some poor soul.  To me green should always be safe.

    Oh and that circ in the forth photo should of course be mounted horizontally unless the system pressure is over 20psi.

    Just my thoughts.


  • RobbieDo
    RobbieDo Member Posts: 131
    Oh nice

    The first pic shows the ground (green wire) wired to the neutral on the outlet, which isn't right. I'm not going to go into full explanation of electrical building wiring but it's not right. Black is hot (120vac), White is grounded conductor (neutral), green is equipment ground and stops transient voltage, harmonics and so on. You should have someone that is qualified correct that, most of the new equipment need reference to ground.
  • timo888
    timo888 Member Posts: 137
    edited April 2011
    indeed - the green grounding wire not attached to outlet ground

    Matthew, that's exactly it -- the green grounding wire does NOT go to the outlet's green grounding screw but is fed into the outlet opposite the red wire. That screwy wiring is what caused me to question the oil company's wiring.


    I had a regional (mid-atlantic) service organization "trained in Buderus" come to my house two years ago to drain the tank and check the anode, as required by Buderus warranty. The tech arrived with an adjustable wrench and a power nozzle. I lent him my metric sockets to get the cleanout plate off. Somehow the circulator was working when he arrived but broken after he finished hosing out the tank and brought the system back up. Not sure how. He replaced it but didn't have the correct mount to orient it sideways. System pressure is at 22 psi. Sideways mounting is on my list of things to be addressed. Where is the system pressure set? On the valve that reduces pressure where the domestic water supply enters the boiler?
  • timo888
    timo888 Member Posts: 137
    edited April 2011
    BX connectors


    Thanks for the tips. Will follow up on the anti-shorts on the BX connectors.
  • timo888
    timo888 Member Posts: 137
    will have electrician in


    I'm having an electrician come over to take a look and remedy things. I do believe I will send the oil company the electrician's bill to offset the $770 bill the oil company just sent for me my latest delivery of 170 gallons.
  • VictoriaEnergy
    VictoriaEnergy Member Posts: 126
    maybe not so bad

    The installer may have intended to wire from a low water cut off so the boiler is switched, but the outlet the stays hot, so he thinks he can't use the common, so he's using the green conductor for a non standard use.  The ground is still available via the armored cable jacketing.

    If this is the case, it's wrong, but not a huge deal. 5 yard penalty and repeat the 2nd down.

    The use of the switch as a terminal block by connecting a wire to the screw terminal and push in terminal is another li'l no-no.

    Maybe send the pictures to the installing company and ask them to correct the deficiencies first, and only go to 3rd parties if they refuse. 
    Home Owners Please Note:

    You are receiving advice from some very skilled pros completely free of charge. One of the reasons I participate is to sharpen my own troubleshooting skills. So; did we get it right? I would be grateful if you extend this courtesy back by posting the final outcome of the issue you are inquiring about. Thanks
  • RobbieDo
    RobbieDo Member Posts: 131

    National Electric Code does not allow the use of the " armored cable jacket " as it isn't a continuous ground to the panel. I'm a electrician but I can't do things that aren't up to code or unsafe.
This discussion has been closed.