recessed light fixtures have thermal cutoff sensors installed near the top of the can. If the inside of the fixture gets too
hot, these sensors will interrupt power flow to the bulb, thereby turning it off and possibly preventing a fire due to overheating.
When the inside of the can cools down sufficiently, power is restored to the bulb.
reflector style bulb (R- or PAR- style) will effectively divert heat out of the fixture and away from the thermal sensor.
If you use an A-19 (regular) light bulb instead, then heat is allowed to become trapped inside the can and thus cause the
thermal sensor to repeatedly cut out and restore, causing the blinking effect.
Almost all recessed lights will use some sort of reflector bulb. Check for a label on the inside
of the can that will tell you what size bulbs can be safely used with the fixture.
An additional note on R and PAR bulb selection: these lamps are usually
configured as spotlights or floodlights, or some combination of both. Using a spotlight style bulb will cause concentrated
circles of light to appear underneath the fixture. A floodlight bulb will give you a wider coverage of light. Spots are good
for accenting items, artwork, etc. while floods work well for overall light coverage. Experiment with both types to see what
works best for you – you’ll be surprised at what a difference the correct bulb will do for the atmosphere of your
I’m putting 6” IC-rated recessed lights in my ceiling,
which are visible from the attic. Can I put insulation around these fixtures to keep the drafts out?
Yes. IC-rated fixtures are designed to be in direct contact with insulation. A non-IC
fixture must not have any insulation within 3 inches of the housing. BTW, IC stands for 'Insulation Contact'.
I want to replace an existing fluorescent kitchen fixture
with an incandescent one. Must I do anything to the existing junction box or can I just change out the fixture? Also, if I
want to change the wall switch to a dimmer, can I do that just by swapping out the existing switch with a dimmer?
You should just be able to change out the lights - no problem. And a dimmer can
be used as a replacement for a regular switch - as long as you are using a dimmable bulb (such as an incandescent).