Turn off the breaker, not just the switch.

All you need is "hi dad, need some light?"

Thanks hendricus, tom_o for the advice!

Unfortunately, there would appear to be no way to remove the thermal protector. The unit is one solid (pressed together) unit, and consistent with this, Lightolier lists no replacement parts on their website. I may be able to access (and replace) one of the two units from the attic, but the other is between the first and second floor, so it looks like I will have a permanently burned out light until we remodel the kitchen.

My Dad suggested I wire around the built-in thermal protector and install a new one, but I assume that the physical layout of the unit is part of the thermal control design and that there is no way to do that that would result in a safe installation so I have rejected this alternative.

These parts used to be available. The excuse I heard about that no longer being true was the UL listing. They cannot no longer sell the thermal sensors alone. You can repair the fixtures. There are no fixtures made that cannot be serviced without tearing up the house when properly installed. You will need to purchase new housings of the same model and replace the cylinder which includes the sensor. The bar hanger assembly will remain in the ceiling. The sensors used to cost as much as the new housing anyway.

In answer to your questions:

1) I have seen exactly this same failure mode in several Lightolier recessed lights in my home, built in 1983. Each of the failures was in fixtures over water sources (sink and shower). I, too, had concluded the problem was the thermal protector sensor(s).

2) However, after pulling down the fixture (with power off!) to get the model number (needed to order the correct thermal protector sensor, which IS AVAILABLE from your local Lightolier lighting dealer), I first sprayed electrical contact cleaner into the socket of the malfunctioning fixture, briefly waited for it to dry/evaporate, then turned the power on and tested the circuit and ... viola! ... problem disappeared! Did the same with two other fixtures that ultimately failed completely in the "off" mode: worked there as well. Depending on the extent of the moisture-induced oxidation in the socket contacts, you may have to do this more than once: one of my fixtures required three squirts.

Guess the socket contacts just need to be cleaned every 20 years or so! Only wish I'd thought of this earlier ...

Tell me if this works for you as well ... and thanks for your original posting.

Paulgarden,

How are the fixtures "pulled down"? I cannot see how they are mounted in the ceiling. I'm sure my similar problem with light going on and off is either moisture build up or a thermal sensor problem. I attached an extension cord into the socket and lit a night light. Light went off in 5 minutes, so I'm sure its not overheating.

Thanks,

Jim

dim4fun has your answer. Buy new fixtures and remove the cylinders from the faulty ones. There are 3 or 4 sheet metal screws, usually 1/4" hex heads, located near the bottom, inside the can. Remove them and slide the can up in the ceiling where you can open the J Box and disconnect the wiring, then the clip that holds in the metallic whip.
It is easier to leave the old can up in the ceiling, as the top has a flange which makes it tough to get out.

It will be tough to get the new can to slide in, but once you are past the top part it will go in easy. Push it up into the ceiling, connect it up and slide it down into position. Sometimes the screws won't line up, then it's time for some self tappers and a RA drill extension.

Must be Christmas time because I think I experienced a Miracle. Was able to get the fixture out. Was marking all the wiring so I could change it out.

As I was feeling around the electric junction box, I felt the thermal piece which was attached to the junction box. Next to the thermal sensor was a plastic bag with what appeared to be pieces for alternative attachments of the box. It actually was on the thermal sensor. Also, when I had years ago went into the attic to insure there was no insulation around the fixture, I had removed a lot of insulation directly above the fixture.

I did not know the sensor was located away from the fixture itself. So yesterday, I made sure there was an absence of insulation for about 5 to 6 inches from the sensor.

Put it back together and Voila, turned light on and it stayed on for hours.

Thanks for assisting and listening.

Jim

I followed Paulgarden's advice above, and sprayed some electrical connection cleaner into the socket. The light is now staying on. I'm glad I found this post. My advice would be to go to your local auto parts store and buy a bottle of that stuff for around $8 and see it it will work for you. If it does, it sure beats the work you'd have to do to replace the whole fixture!

I just experienced the same problem. the light would go off and on and I found the thermal protector was getting hot. In my effort to understand what I was dealing with, I found that the black wire connection was loose and was only making contact by a few strands. I re-cut the wire and stripped it, re-secured it and problem solved. the light stays on and more importantly, the thermal protector stays cool to the touch. My advice is to start with the simple.

I have exactly the same situation. My house was built in 1987. I have Lightolier fixtures. The thermal sensor is a black cylinder stuck in a half inch conduit punch hole. It has three wires: one for neutral, one for hot, and one for load, meaning the light. Why three wires? Because it has a little heater inside that's supposed to start turning the fixture off if it overheats in the presence of insulation. In my case the fixture has no insulation near it, and the switch simply failed and blinks now, regardless of the type of light that's plugged in. Cleaning the sockets is a good idea, but in terms of this problem it's not relevant because the sensor is in a completely different housing from the lamp itself. The blinking is independent because of that heater. Well, I removed the thermal switch, and took a look at the part number and I'm happy to say you can buy them. I see them on various electrical supply store sites and there's also people selling them through Amazon. The unit in my fixtures is model RP1B. Several companies make this, so you can search for it online. I've seen prices ranging from $40 each down to $13. I plan to ask an electrician friend about the code. Since the fixture has no insulation within I'd say 10 ft of it, I don't think the sensor is necessary at all. However it might be required by model certification. So eventually I'm going to replace it. For now it's disconnected. By the way, I checked the internal resistance of the sensor... It's supposed to be about 7,000 ohms, and instead it's down around 3,000. I can't understand why it would change resistance, but that's going to draw twice as much power as the sensor was intended to receive.