I am doing a remodel on my rental. One of the things being done is replacing electric baseboard heat with a mini-split system. So that involves removing the baseboards and capping the wires.

If I disconnect the wires in the breaker panel mark and cap them, then mark them as to where they went, Do I still need to put a dead front on the wall where the cables where or can I simply abandon them and bury them? Same question about the thermostats...dead front or bury? I usually know this stuff, but in this case I'm not sure.

  • Or this? How to deal with abandoned wire?
    – isherwood
    Feb 23, 2022 at 14:35
  • Or this? Leaving old wiring unconnected in a wall
    – isherwood
    Feb 23, 2022 at 14:36
  • Thanks for the links @isherwood I should have searched first for a previous answer. As others have said, code is bare minimum and I agree. I asked the question because I want to do "best practice". Unfortunately the title to my question was misleading in that regard. I'm going to edit the title to make it more clear. Feb 23, 2022 at 17:09
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    That's reasonable, but the code seems to be open to interpretation--once a wire is abandoned outside a box it's no longer a wire. As far as at least some inspectors are concerned, you could hang pictures with it.
    – isherwood
    Feb 23, 2022 at 17:17

2 Answers 2


Can't abandon unless you completely destroy.

To abandon cables in walls, you must completely destroy all parts of the cable that you can reach, on both ends, so there is no possibility of anyone ever energizing it again.

That precludes twisting any wires together; if you can reach it you must sever it.

You are particularly not allowed to twist the ends together and bury it, and then leave the wires in the service panel. That is inviting someone to put 240V across the wires, and if your twisted ends aren't perfect, they may just sit there and parallel-arc and start a fire.

See NEC 300.15 (bottom here): "where the wiring method is...NM..., a box... shall be installed at each... termination point".

See also 300.12, "Non-metallic... cable sheaths shall be continuous between boxes".

The only way to eliminate those obligations is destroy the wires beyond usability. Ontario put out a clarifying bulletin to that effect (Bulletin 12-25-1): "Unused wiring shall be properly terminated, or removed. Wiring that is concealed and inaccessible shall be cut off where exposed so as to be too short to be reused."

If you want to preserve the wires for future use (good idea) you need a junction box.

In that case, yes - there must be a junction box, and the box cover must be 100% accessible without removing any wall material or doing any damage to the building finish. Even painting it over isn't legit; wallpaper is Right Out. (unless you want to properly create an opening for the J-box, and then line the J-box cover with a scrap of wallpaper, as I often see done).

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The best camouflage for an unused junction box.

Or, change it from "blank junction box cover" to "useful outlet". The wires are there.

If you want something to decorate the junction box cover with to make it look less tacky, and the in-wall wires are black and white, then you could always stick a regular old electrical outlet in the junction box. Use the legacy wires to connect it to a 120V breaker (white to neutral of course). Note a 240V/20A breaker can feed two 120V/20A circuits. (one on each side). So you already have the breaker lol.

"This apartment has too many electrical circuits and outlets" is something no tenant has ever said.

  • @Mazura It's rare for me to DV; usually people fix it and then I forget to un-DV lol. Cites added. Code doesn't explicitly say "you must obliterate", but it's clear that if you don't obliterate, 300.1x apply. Never lacking an opinion on any matter, the ever-intrusive Ontario ESA issued a bulletin to smash all ambiguity on the subject. Feb 23, 2022 at 3:20

You can abandon them in the wall.

An electrical inspector once told me that a good electrician will splice the hot and neutral together in the buried end so that if, later, someone mistakenly tries to reconnect the wires at the other end, it will immediately trip a breaker. I personally wouldn’t do that but there you go.

  • 2
    Wow... that inspector's advice sounds so much like this question. Maybe you should watch the video there to see if it's the same guy...
    – FreeMan
    Feb 22, 2022 at 17:30
  • @FreeMan it’s not. He’s a good guy but just a bit over enthusiastic. I shouldn’t be ragging him on the internet, he’s been really helpful and patient with me as a homeowner doing his own permitted work. Feb 22, 2022 at 17:42
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    I believe you are supposed to cut and remove all accessible portions of the abandoned cable, so there would not be an "end in the panel," or it would be a cut off stub immediately as the cable entered the panel (assuming no access outside the panel.) If you want to leave it "for future use" terminate it at a junction box. If abandoning, make it impossible to reconnect without doing additional work that implies taking responsibility for the "lost" cable. So, if removing junction boxes, pull out and cut off all cable you can get to from the junction box opening, etc.
    – Ecnerwal
    Feb 22, 2022 at 19:45
  • I like the idea of repurposing the runs as outlets, of course some re-wiring in the panel would be required to convert from 240 to 120, otherwise that hair dryer would REALLY HOT! (Kidding). Also need to investigate the topology and perhaps a couple of the runs could feed the mini splits (there will be 2 outdoor units due to the layout of the house). Thanks every one for your comments and answers. Feb 23, 2022 at 5:40

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