Quick answer: Flickering in a single fixture is often a loose bulb, a failing LED, or a dimmer that is not compatible with the bulb. Flickering throughout the house, flickering when large appliances start, or lights that brighten and dim dramatically can point to loose connections or a problem with the electrical service, which should be checked by an electrician promptly.

Not all flickering means danger, but some flickering is an early warning of a connection that is heating up. The pattern tells you a lot.

Flickering in one fixture

Likely causes:

  • A loose bulb. Turn the fixture off, let the bulb cool, and tighten it.
  • A failing LED bulb. LEDs can flicker as their drivers age. Try a new bulb.
  • Dimmer incompatibility. Older dimmers designed for incandescent bulbs often cause LEDs to flicker or buzz. An LED-compatible dimmer usually solves it.
  • A loose fixture connection. If new bulbs do not help, the connection in the fixture or switch may be loose.

Flickering in one room or circuit

If several lights on one circuit flicker, a loose connection at a switch, outlet, or splice is a common cause. Loose connections create resistance and heat. Have an electrician inspect the circuit.

Flickering when appliances start

A brief dim when the AC compressor, well pump, or another large motor starts can be normal. Noticeable flickering every time, or dimming that gets worse, may indicate an overloaded circuit, a weak connection, or a service issue.

Whole-house flickering or lights brightening and dimming

This is the pattern to take seriously. If lights in many rooms flicker, or some get brighter while others get dimmer, the cause may be a loose or failing connection in the panel, meter base, or utility service, including a failing neutral. Turn off sensitive electronics and call an electrician and your utility promptly. See what to do in an electrical emergency.

Storm and outage flickering

During storms, utility switching can cause brief flickers across the neighborhood. If neighbors see it too, it is likely on the utility side. If it continues after the weather clears, or only your house is affected, have it checked.

Frequently asked questions

Are flickering lights dangerous?

Sometimes. A single flickering bulb is usually harmless. Flickering across multiple rooms, with a burning smell, or with warm switches or outlets can indicate a loose connection or service problem that creates heat.

Why do my LED lights flicker on a dimmer?

Many older dimmers were designed for incandescent bulbs and are not compatible with LED loads. Installing an LED-rated dimmer and dimmable bulbs typically fixes it.

Why do my lights dim when the air conditioner turns on?

A brief dip as a large motor starts can be normal. Significant or worsening dimming may point to an overloaded circuit, loose connection, or service issue.

Should I call the power company or an electrician for flickering lights?

If neighbors are also affected, contact the utility. If only your home is affected, call an electrician. For dramatic brightening and dimming, contact both.

Copperhead Electrical provides residential electrical service across Charleston, Mount Pleasant, West Ashley, James Island, Johns Island, Daniel Island, North Charleston, and Summerville. Call 854-444-6516 or request service online.