I'm looking to run a 120V outlet about 3 feet from the breaker to a closet for a gas-fired tankless water heater. I think I can manage it myself, but I'm worried about the electrical code that requires the NM cable to be supported within 12 inches of the breaker and outlet. I really don't want to cut large holes in the drywall since I have no experience or desire to deal with patching it up. Is there a way to do this while minimizing any major damage to the walls?
5 Answers
Absolutely, you can do this! Even if you're uncertain about the wiring connections, you can run the line and let a professional make the final connections. It's a pretty straightforward process, but do keep the necessary codes in mind. Nobody wants electrical issues later on!
There are a few ways to go about this, but the main thing is to ensure the wire is protected from damage. You can go with surface-mounted raceway or fish the wire through building materials like studs. As long as you get the right fittings and keep in mind the 12-inch support rule where required, you should be good to go!
Is it true that just running the cable through a stud won't satisfy the 12-inch requirement? Am I right in thinking I need to open up the wall to actually "secure" it properly?
According to NEC 334.30(B), you can actually leave NM cable unsupported if it’s fished through a finished wall. So you shouldn’t have to cut too many holes just to meet the support requirements. But do be careful—there could still be live parts in your panel, even with the main breaker off.
Thanks! That’s reassuring to know. Are you saying there might still be live parts even after shut-off? I thought it was safe once I turned off the main breaker.
Yeah, be cautious! Fishing the wire can be tricky; it’s more challenging than it seems sometimes!
If you're asking about DIYing this, you might want to consider hiring an electrician instead. It'll save you a lot of headaches down the line, especially if you're not very familiar with electrical work.
Totally agree! And then you might still need someone to handle drywall afterward.
I might take it on myself. If you're experienced with a multimeter, you'll be fine. But if not, maybe it's better to leave it to the pros!
I'm not an electrician, and I can't speak for your local codes, but have you considered using MC instead of NM cable? MC has fewer support requirements and might be a better option, although it's often for exposed areas since it’s easier to damage than NM.
That’s interesting! I'll definitely look into it. Thanks for the tip!
Just to clarify, MC is indeed metal-clad, not metallic conduit—so keep that in mind!

I'm pretty confident about the electrical work; it's just the big hole-cutting part that I'm trying to avoid! Maybe I should just bite the bullet and tackle it.