Flickering Lights: 6 Causes, From Harmless to Call an Electrician Now

One light flickers

1. The bulb. A loose or failing bulb is the usual answer. Tighten it or swap it.

2. The dimmer. LED bulbs on an older dimmer flicker, buzz or glow when off. An LED-rated dimmer fixes it. This is a quick job covered under switch and dimmer installation.

3. The fixture or switch. A worn socket or a loose wire at the switch can cause flicker that comes and goes when you touch the switch. That connection is heating up and should be repaired.

One room or one circuit flickers

4. A loose connection on the circuit. A backstabbed outlet or a tired wire nut somewhere along the run can make every light downstream flicker. Loose connections make heat, and heat is how electrical fires start. Have it found and fixed with proper electrical troubleshooting.

5. A large load on the same circuit. A brief dim when a vacuum or microwave starts points to a shared circuit near its limit. A dedicated circuit for the appliance solves it.

The whole house flickers

6. A service or neutral problem. If lights across the house dim and brighten, especially when some get brighter while others get dimmer, suspect a loose neutral at the panel, the meter or the utility connection. This can send damaging voltage to your electronics. Treat it as urgent and call an emergency electrician. If the problem is on the utility side, we will tell you and you can report it to them.

A short, mild dip when the furnace blower, air conditioner or well pump starts is common. If it has grown worse, the panel or the service may be undersized. See our panel upgrade guide.

A quick way to narrow it down

1. Note which lights flicker and when
2. Try a new bulb in one of them
3. Check whether a big appliance starts at the same moment
4. Ask a neighbor whether their lights flicker too

If the neighbors see it as well, call the utility. If it is only your house, call an electrician.