A can light's thermal overload protector disconnects the electricity to the light bulb when the lighting fixture's temperature rises above its maximum level. A functioning thermal overload protector turns on the electricity to the light bulb once it detects the fixture's temperature has dropped to an acceptable level. Replacement thermal overload protectors must match the original's thermal and voltage ratings. If the thermal overload protector routinely turns the light on and off, compare the light bulb's wattage rating to the fixture's maximum wattage rating. Light bulbs with a wattage rating exceeding the fixture's rating will overheat the fixture.
Turn off the can lighting system's circuit breaker.
Open the cover on the can light's electrical box, using the correct screwdriver to remove the cover's retaining screw. The electrical box mounts to the top or side of the can light's housing.
Remove the thermal overload protector's retaining clip with a slotted screwdriver. The thermal overload protector mounts against the can light's housing, usually near the top, and has two wire strands entering the electrical box.
Follow the thermal overload protector's wires into the can light's electrical box. Remove the wire nuts holding the protector's wires to the fixture's wires. Separate both sets of wires and pull the thermal overload protector off the light fixture.
Slip the new thermal overload protector's wires into the can light's electrical box, using the same hole the old protector's wires used.
Position the thermal overload protector on the can light's housing. Secure the overload protector to the housing with the retaining clip.
Connect the thermal overload protector's interchangeable wires to the can light's wires. Cover each wire connection with a wire nut. Adjust the overload protector's wires until the wires' insulation does not touch the can light's housing.
Set the cover on the can light's electrical box. Tighten the cover's screw with the correct screwdriver.