I'm trying to use a VoIP system in my home's existing phone lines, which I have little knowledge of. The two bedrooms are connected. I can hook up my Obitalk adapter in one and get a dial tone in the other room.

The kitchen is a mystery. There are two six strand UTP bundles coming through in the panel, and only one pair actually has a current running through. I can turn off the VoIP and still get current. I can turn off my breakers and still get current. I measured it at about 26 V. My impression is it's coming from either the phone company, an old security system, or something else that has a battery backup that I haven't found. I figure the phone company would have a disconnected message if I dial out. I'm not sure about security companies since I've never had one. What seems likely?

Whatever the case, I'd like to connect the kitchen so it's on the same circuit as the bedrooms. What should I be looking for to do that? I know there is an access panel in a closet which appears to have phone wire bound together with some of those twist on caps.

  • 1
    Hello, and welcome to Home Improvement. Google "phone toner" to see a useful tool for this kind of work. Commented Oct 2, 2018 at 7:01
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    you can unplug the house wiring from the outside phone customer access box.
    – dandavis
    Commented Oct 2, 2018 at 16:07
  • @dandavis That works on a new setup, but in my area plenty of older houses don't have a proper network interface (aka customer access box) unless they have gotten FIOS. If the internet access is via the local cable TV company then the abandoned phone wiring may be hard to figure out. Commented Oct 3, 2018 at 3:15

2 Answers 2


Based on the description, it sounds like you (or a previous owner of the house) USED to have traditional phone service and do not have that any more. If you are still paying for phone service then you may want to look into porting the number to VOIP instead of simply turning off the phone service and using VOIP with a new number.

Find the Network Interface

The network interface is the connection from the phone company network to your local equipment (phones/fax/etc.) With newer homes this is typically a clearly marked box with an easy to disconnect connection between the inside wiring and the phone company incoming lines.

In an older house this may be simply a small terminal block "anywhere" with one pair of wires for each phone line coming in and one or more pairs of wires (like the 3-pair UTP you found) going to the rest of the house.

A newer network interface will typically be on the outside of the house or together with electrical and other connections inside the house. An older network interface could be "anywhere", though near the electrical panel is typical. If your utilities come from overhead wires (aka telephone poles) then you can often trace the wires around the house and look for where the phone wire (typically smaller than the main electrical service) goes into the side of the house and look for a terminal block on the other side of the wall. If you have underground utilities then it will be a little harder to find where the wires enter the house.

Disconnect the Old

Once you find the network interface, disconnect either the incoming (phone company) or outgoing (home wiring) wires. With a modern network interface, it should be very easy to disconnect the home wiring. With a terminal block, it may vary. If you are not 100% sure, take a picture and/or mark the wires clearly so that you can put everything back the way it was previously. If you disconnect some wires and you still get 26V on the UTP then you haven't found the real network interface - but you may disconnected one section of phone wiring from another such that your VOIP would only work in part of the house.

Connect the New

Depending on how the VOIP works, you may be able to connect it directly to the network interface. However, many systems are designed so that you can simply plug the VOIP line into any existing phone jack and all other phone jacks on the house (sharing a linked pair of wires) will be instantly "live". You can use a line splitter to make the the jack used for the VOIP connection live at the same time.


The phone lines do have power on them but it is limited and if you tap the line the phone company will detect the draw and turn your line off or send a tech to find the problem. Back in high school I built a small circuit to create a hold button using the system voltage. Unfortunately my little device drew enough current that the phone company sent someone out. Luckily my mom saw the truck and unhooked it , the tech said he was sent to find a problem but it had disappeared, if mom would not have unhooked the hold button we would have been charged for the work. I don't remember what the threshold was but it was very low so trying to use the phone line power could end up costing quite a bit or the system may shut your line down thinking a phone is off the hook.

  • I think the OP is asking about reclaiming the wires, not the current in the wires. Otherwise, you have an excellent answer there.
    – mrog
    Commented Oct 2, 2018 at 19:40
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    @mrog yes, it's true, I definitely would like the current to go away. Though this answer is useful since it encourages me to be more cautious in my testing. :)
    – OEP
    Commented Oct 3, 2018 at 5:21

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