How do I fix a recessed lighting fixture?

[Wade Lippman]

I have posted this at two DIY forums without getting a meaningful answer. So I am going to try here.
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I have about 20 recessed light fixtures. About half are in insulated ceilings and half are uninsulated. They are Noralighting NHIC-17QAT.
http://www.noralighting.com/Product.aspx?pid=7669
They are 10 years old.

A couple months ago I put a LED bulbs in to see how they worked. After a few weeks one that had a LED bulb stopped working. It turns out the heat sensor that prevents the fixture from overheating went bad. Noralighting was kind enough to send me a couple replacement sockets with heat sensors. They say the LED was pure coincidence.

They told me that the connection had to be made at the junction box; if I just wire nutted it in where the bulb is, the connections might overheat and fail. As far as I can see, you can't get to the junction box without ripping the ceiling open; which would seem like a bad design flaw.

Questions...
1) How on earth would I make connections at the junction box. It looks to me like I would have to rip the ceiling open. Presumably there is an easier way, but it beats me what that might be.
2) The LED bulb is much cooler in operation than the incandescent bulbs the fixture was designed for. Would wire nutting a new sensor in really be a problem? Even if it was a problem, it would just be an open circuit, which would be plenty annoying but not a serious problem. Am I underestimating this?
3) Some of the fixtures are in 17' high ceilings. Trying to fix the fixtures would be a real problem. If I ran LED bulbs in them, could I just short the heat sensors out if they failed? They don't really get hot to the touch; it is hard to see how they could start a fire.

Thanks for your help.

[Pat Barry]

Wade, are these on dimmer switches? If so, you need to get LED compatible dimmer switches.

Edit - obviously the current flow, and therefore the heat, is much lower for an LED bulb as compared to incandescent. I can't see how lack of heat would be an issue.

[Bill ThompsonNM]

Any chance the bulb housing comes out to give you access to the connector box? The only problem I see with running without the temperature sensor is if someone changes back to a halogen bulb. You are probably right that the sensor is open if blown. Are you sure the top of the LED bulb which handles the AC to DC conversion didn't get too hot? I've had some high wattage LEDs that even came with a fan.

I'd play with one on a bench with a conventional socket to see how hot it gets. Then if you can't get the lamp housing out I'd consider doing what you propose but it probably violates code.

That's one reason I really don't like those pot lights---not very serviceable.

[Paul F Franklin]

Questions...
1) How on earth would I make connections at the junction box. It looks to me like I would have to rip the ceiling open. Presumably there is an easier way, but it beats me what that might be.
2) The LED bulb is much cooler in operation than the incandescent bulbs the fixture was designed for. Would wire nutting a new sensor in really be a problem? Even if it was a problem, it would just be an open circuit, which would be plenty annoying but not a serious problem. Am I underestimating this?
3) Some of the fixtures are in 17' high ceilings. Trying to fix the fixtures would be a real problem. If I ran LED bulbs in them, could I just short the heat sensors out if they failed? They don't really get hot to the touch; it is hard to see how they could start a fire.


1. If you remove the trim ring, you will find 2 or three screws (sometimes they are wing nuts) inside the housing that secure the housing to the mounting frame. If you remove those, you can either lower the housing through the hole or push it up into the open space (you are limited by the flex conduit containing the wiring). Then you can reach through the hole, remove the inside of the junction box (the are made with both sides removable just for this reason) and make the connections you need. It's a bit tight space-wise, but doable.

2. If you are going to go this route, I would suggest using UL listed butt crimp connectors, not wire nuts. They are smaller and make a secure mechanical connection as well as electrical.

3. I don't recommend ever defeating a built in safety feature or interlock. The problem in this case is you have no way to ensure that a regular bulb isn't installed in the future by someone else. Plus, LED's operating normally may run fairly cool, but the heat does build up inside the can. Furthermore, under some failure conditions, the bulb electronics can produce far more heat that they do under normal operation. And finally, although I admit it is an unlikely scenario, your insurance company would have a basis for denying a claim if you modified the fixtures in this way, which for me, is reason enough, however unlikely, to do it the way the manufacturer specified. In other words, method 1.

[Chris Padilla]

Since the manufacturer said you need to make the connections at the j-box, why not ask them how you get to the j-box if you have no access from above.

Your only access point is to drop the can and disconnect it and then MAYBE you can reach the j-box and MAYBE you have enough room to work through that 6" hole.

[Brian Ashton]

I'd be pulling the housing out of the ceiling and seeing if there was enough wire to pull out to where you can work on it and add another junction box. Wire it up as per the instructions and stuff it all back in the ceiling, obviously trying to push the new junction box far as possible from the light housing... And then hope there's no fire cause you don't have any fire insurance anymore. YMMV

[Wade Lippman]

The light fixture spontaneously started working again 2 weeks after it broke. Could the heat sensor really take 2 weeks to reset, or was there a loose connection that probably had nothing to do with the heat sensor?
I tried to lower the can, but the whip isn't long enough to allow it. I am reluctant to push the can up for fear I won't be able to get it back down.

Anyhow, I measured the LED bulb at 112F, while an incandescent bulb on the same circuit measured 247F. There is a dimmer on the circuit, but the bulb says it is dimmer compatible; do I still need a special dimmer for it?

There was no way to measure the temperature in the can, but I put the LED bulb in an open fixture. I then measured the bottom of the bulb at 100F, the top side at 124F, and the base at 119F. I then did the same for a comparable 65w incandescent bulb; it was 250F bottom, 135F top, and 210F base. The relatively low temperature of the incandescent top was surprising, but still, the can would have to be much hotter for the incandescent bulb than for the LED. (The fixture is rated for 75w, but I only have 65w)

So, 3 questions:

1) Why did the fixture fail, and then come back 2 weeks later? Do they take 2 weeks to reset, or was it a bad connection that fell back into place? Or something else?

2) I like the idea of using a crimp connector instead of trying to reach the junction box. Is there any downside to that? (Since the LED bulb is so much cooler than the incandescent bulb I "think" shorting the heat sensor "ought" to be okay, but I can see that deliberately creating a code violation isn't something to be done lightly)

3) The package said the LEDs were dimmer compatible, but the bulb doesn't. The bulb does say it isn't for use in an enclosed fixture. Would a can open at the bottom be an enclosed fixture? If it is, presumably it means the heat might cause the bulb to fail; not the fixture. Right?

I appreciate your help.

[Paul F Franklin]

It's pretty hard to "lose" the can pushing it up...since it's tethered to the junction box which is mounted to the frame right next to the hole.

The thermal cutouts usually reset in a few to 10s of seconds....essentially however long it takes fixture to cool off a bit. No way it would take 2 weeks. I have seen poor connections act that way....work for while...stop for a while, and so on. Thermal cycling or shock or vibration can cause a poor connection to make and break.

Crimp connection is fine.

Non-dimmable LED's will just act weird if you put them on a dimmer. Will usually stay on at more or less full brightness until dimmer is turned down past a certain point, when they may go on and off or just stay off. Dimmable LED's on dimmers not rated for LED's may work just fine, but often they won't dim down as far as desired, or all the dimming will happen in a narrow part of the mechanical range of the dimmer knob. Bottom line, if the combination you have dims the way you want it to, then it's fine.

Recessed fixtures with open trims (as opposed to a shower trim, for example, are not consider totally enclosed fixtures. In any case, as you thought, the warning has to do with premature failure of the bulb, not damage to the fixture.