How to remove old-work ceiling light fixture box attached to conduit pipes

Question

I am trying to install thin LED recessed lights in my hallway. I need to remove the old ceiling box, as shown in the picture. I tried to remove the box for the whole day but was unsuccessful. I cut the drywall around it ad is sure that it is not fixed with a joist or anything.

I removed the punch knockouts and found that the whole ceiling box was connected to three conduits using the connected, as shown in the picture below. The conduit brings in the wire for a three-way switch system to the said ceiling box. There are the big nuts that are tightly screwing these conduit connected at the backside of the box.

Please give any suggestions as to how to remove the box. I still want to use the same wiring so don't want to damage the conduits or wires coming out of them.

Thank you

Answer 1

The existing answers are correct in that you should not, in all likelihood, be attempting to remove this box or the wiring or the conduit.

However, to actually answer the question you asked, since there are occasions to actually remove and replace a box^*

The nut that is visible inside the box on the cable clamp/conduit nipple is a standard righty-tighty, lefty-loosey nut. Usually, you thread the nut on to the nipple, tighten it by hand, then place blade an old flat-blade screwdriver against one of the notches sticking up on the nut tap it with a hammer to tighten it down. To loosen it, simply tap in the opposite direction (turn it counter-clockwise). One or two taps should have it loose enough for you to then turn it by hand to back the nut off.

Tap in the direction of the green arrow to tighten and the red arrow to loosen.
^{Image courtesy of topaz-usa.com. First small image I found for what I was after. Arrows are own work.}

Again, unless you are completely removing the circuit, make sure you replace the box when you're done. All wiring connections must be made in an approved box.

---

^*Valid times to remove/replace the box include replacing a light-weight ceiling fixture (mounted to a standard-duty box) with a ceiling fan (mounted to a heavy duty, fan-rated box). Also, when adding a circuit, you may exceed the legal fill for a box, so may choose to replace the box with a larger/deeper one. There are other times, these are just 2 examples.

Answer 2

Removing this box is not a good solution when there are rigid conduits bringing wires into this existing box. The main reason for this is that those wires would still need to terminate into an accessible junction box. On top of that there is just no simple way to adapt the existing rigid conduits for connection to the floating connection box on a recessed fixture.

This may be a doable project IF:

1. You had access to an attic space above this ceiling
2. You have the experience and perseverance to work through the serious rework of the existing conduits to some other accessible junction box in the attic.
3. Keep in mind that the wires in those conduits may very well not be long enough when you go to try create a new junction box - which then entails pulling new wires through those conduits back to their other connection points.

The practical way to deal with this is to keep the existing ceiling boxes and install new surface mount LED fixtures. If you insist on the recessed fixtures then you will need to cut new holes in the ceiling for those fixtures near the existing electrical box and then run new flexible conduit from that existing box over to the recessed fixture floating connection box. If you choose this latter route then just purchase suitable flat white cover plates for the existing electrical box. If the ceiling is a different color the flat cover plate can be painted once installed to coordinate with the ceiling.

Answer 3

You need to stop destroying stuff right now.

Since your project is this light, you are assuming the universe is gracious enough to have ALL the wires in these conduits be ONLY about this light. That is a faulty assumption. There could be other circuits you don't know about; your plans could break them.

Now to start with, nobody uses conduit for their health. They use conduit because it's legally required in the situation they are in - commercial building, local requirement, etc. So when you see conduit, expect it's a requirement.

However, conduit is easier than you're making it. You just need to learn the craft of it. It might not actually be that big a deal to run conduit from this box to your planned lamp location. You could demote this box to simply being a splice box and serve the new lamps from here. Use a blank cover plate and also put 10 cent covers into the holes you erroneously knocked out.

By the way, the reason "removing the box" is impractical is because you don't alter the piping with the wires in it. You go to the boxes they connect to, and pull the wires out of it. Then you modify the piping as needed and pull the wires back in.

Keep in mind every splice, tee and sharp corner need to be at a junction box, and the box cover must be accessible forever.