Flickering Lights: When It's the Bulb and When It's the Wiring
How to diagnose flickering and when it signals a real problem.
By Electric · · 4 min read
Flickering lights are annoying, but they're also one of the easier problems to diagnose if you know what you're looking for. Most of the time, it's just a bulb that needs replacing or a fixture that's loose. But sometimes that flicker is telling you something more serious is going on behind the wall, and that's when you need to stop guessing and call an electrician. I've been doing this long enough to know the difference, and I want to walk you through how to figure out which one you're dealing with.
Start with the simplest fix: the bulb
Before you worry about anything else, check the bulb itself. A bulb that's loose in its socket will flicker every time, or it will flicker randomly depending on vibration or temperature. Screw it in tighter. If that stops the flickering, you're done. If the bulb is loose in a ceiling fixture, make sure the power is off at the breaker, then tighten it. A bulb that's burned out or near the end of its life can also flicker before it goes dark completely. Replace it with a new one of the same wattage. That solves about half the flickering complaints I get calls about.
LED bulbs and dimmer switches don't always get along
If you've switched to LED bulbs recently and you're seeing flicker on a dimmed circuit, this is probably your culprit. Not all LED bulbs work well with older dimmer switches. The dimmer was designed for incandescent bulbs, which tolerate the electrical signal differently. You've got a few options here. Buy LED bulbs that are specifically rated for use with dimmers. They cost a little more, but they work. Another option is to replace the dimmer switch itself with one that's designed for LED use. If you're not comfortable swapping a switch, this is a good time to call us. It's a quick job and fixes the problem for good.
Check if the flicker happens in just one room
If flickering is isolated to one room or one circuit, the problem is usually contained to that area. It could be a loose wire at the outlet, a bad connection inside the fixture, or a device on that circuit that's drawing power unevenly. Unplug everything on that circuit except one lamp, then turn the circuit back on. If the lamp still flickers, the problem is in the wiring or the fixture itself. If it stops, plug things back in one at a time to find which device is causing it. Sometimes it's a refrigerator, a space heater, or even a microwave that flickers the lights when it runs. If the flicker comes back when everything is plugged in, you've found your problem device. Replace it or stop using it. If the lamp flickers even when nothing else is plugged in, you need an electrician to check that circuit.
When flicker means a bigger problem
Flickering that happens throughout your house or in multiple rooms is different. This usually points to a loose connection somewhere in the main panel or at the meter, or sometimes at the utility company's connection outside your house. This is not something to ignore. A loose connection generates heat, and heat in an electrical system can cause fires. If you see lights flickering all over the house, or if you notice it happening more often, call us right away. We can test the connections at your panel and meter to confirm what's going on. If it's a utility company problem, we can help you get in touch with them, but usually a loose connection on your side is something we can fix in an hour.
The flicker that comes with other signs
Pay attention if the flicker shows up alongside burning smells, buzzing sounds, or outlets that are warm to the touch. These are warnings. A burning smell usually means an overheated wire or a failing component. Buzzing often indicates a loose connection that's arcing. Warm outlets mean current is meeting resistance, and that resistance is creating heat. None of these should be ignored. Turn off the circuit if you can identify which one, and call an electrician the same day. These are fire risks.
What we check when we come out
When Electric Connection comes to your house for flickering lights, we start by testing the voltage at different points in your system. We check the main panel, the circuit breaker for that line, the wiring in the walls if we can access it, and the fixture itself. We look for loose connections, corroded terminals, and damaged wire insulation. We test for voltage drop, which tells us if current is meeting too much resistance somewhere. Then we tell you exactly what we found and what it'll take to fix it.
Flickering lights are usually simple, but the only way to know for sure is to test them properly. If you've replaced the bulb and checked the obvious stuff and the flicker is still there, give Electric Connection a call. We'll figure out what's going on and fix it right.