Vent, Valve & Volt
Lights flickering: one fixture or the whole house?

You can fix this

Likely cause: a loose or failing bulb

A bulb that is not seated firmly, or is wearing out, flickers. Tightening or replacing it fixes it.

Why this happens

Family Handyman and This Old House both start flicker troubleshooting at the bulb: tighten the bulb first, then replace it if the flicker continues. Siemens notes that a loose bulb-to-socket connection can even trip an AFCI breaker.

How to fix it

  1. Turn the switch off and let the bulb cool before you touch it.
  2. Turn the bulb snug by hand. Do not force it.
  3. If it still flickers, replace it with a new bulb of the same base and a wattage the fixture allows.
  4. If you are on a dimmer and using LEDs, use bulbs marked dimmable.

When to stop. If the socket looks scorched or corroded, or the flicker continues with a new bulb, call a licensed electrician.

If this does not fix it, tell the licensed electrician

  • Which fixture flickers and that a new, tight bulb did not stop it.
  • Whether it is on a dimmer, and what bulbs are in it.
  • Whether the AFCI breaker for that room has tripped.

Build the full list: what to tell the licensed electrician.

Start this troubleshooter over

References (every fact above comes from one of these pages)
  1. Family Handyman: What flickering lights mean
  2. This Old House: How to fix flickering lights
  3. Siemens: AFCI and GFCI homeowner brochure (PDF)

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