Flickering ranges from a loose bulb to a serious service problem. Where it happens tells you a lot.
Why does one light flicker?
Usually a loose or failing bulb, an LED that does not match its dimmer, or a worn switch. Try a different bulb first. See LED dimmer flicker.
Why do my lights dim when the AC or a big appliance starts?
A brief dip when a motor starts is common. Dimming that is deep, lasts, or is getting worse can point to an undersized or loose service or feeder connection, or a panel at its limit. See panel upgrades.
When is flickering dangerous?
- Lights across the house flicker, or some rooms get brighter while others dim.
- Bulbs burn out unusually often.
- Flicker comes with buzzing, warm switches or a burning smell.
Brighter-and-dimmer behavior can mean a lost or loose neutral, which can damage electronics and overheat wiring. Turn off sensitive electronics and call your utility and an electrician promptly.
Common questions
Why do my lights flicker when the AC turns on?
A brief dip when a large motor starts is common. Deep or worsening dimming can mean a loose connection or an overloaded service and should be checked.
Can flickering lights cause a fire?
Flickering itself does not, but it can be a symptom of a loose connection that overheats. Have persistent or whole-house flickering checked.
General information for California homes under the California Electrical Code (based on the NEC). Local rules and inspectors can vary. Not a substitute for an on-site inspection. Never work inside a panel, at the meter or on live circuits.