Recessed light turns on then off repeatedly

Symptoms

• Light turns on, then shuts off after a few minutes, then comes back on after cooling
• Cycling happens more in warmer weather or after the light's been on a while
• Only affects one or a few specific fixtures

Likely causes

• CommonBulb wattage too high for the fixtureRecessed cans have a maximum rated wattage, and exceeding it triggers the built-in thermal safety cutoff.
• CommonInsulation packed too closely around a non-IC-rated canCans not rated for insulation contact can overheat if attic insulation is touching them.
• PossiblePoor ventilation around the fixture housingEnclosed or poorly ventilated cans trap heat even with a compliant bulb.
• PossibleA failing thermal protector inside the fixtureThe safety switch itself can fail and cycle even under otherwise normal conditions.

What to do

1. Check the wattage label inside the can and compare it to the installed bulb's actual wattage.
2. Switch to a lower-wattage LED bulb, which runs much cooler than incandescent or halogen options.
3. If accessible from an attic, check whether insulation is packed directly against a can not rated for insulation contact ('IC-rated').
4. Pull back insulation from a non-IC-rated can, maintaining any required clearance per the fixture's markings.
5. Let the fixture cool fully and test again after switching to a lower-wattage LED.
6. If cycling continues with a compliant, low-wattage LED bulb, the fixture's thermal protector may have failed.
7. Have an electrician replace the fixture if the thermal cycling continues after switching bulbs.

Tools and parts

When to call a pro

Call an electrician if a lower-wattage bulb doesn't stop the cycling, or if you're unsure about insulation clearance requirements around the fixture.

Safety