Why Do My Lights Flicker?
6 Causes and Fixes
Some flickering is harmless. Some is a fire warning. Here is what is actually happening when your lights flicker and how to tell which kind you have.
Quick Answer
Lights flicker for six reasons, in order from harmless to serious: a loose bulb, an LED on an incompatible dimmer, a loose wire connection at the fixture or switch, an overloaded circuit, a large appliance causing voltage drop, or a failing main neutral. The first two you can fix yourself. Flickering across the whole house at once is the most serious and needs an electrician immediately.
The first question to ask with flickering lights is always: is it one light or every light? The answer tells us whether we're looking at a bad bulb and a dimmer problem, or something at the panel that could burn the house down. They're really different calls, and our crew at Newman Electric has handled both ends of the spectrum across Vancouver WA for years.
Figuring out what kind of flicker you have is the first step. Start by watching it for a minute. Is it one fixture or the whole room? Does it happen all the time or only when something else turns on? Is it a slow pulse, a rapid stutter, or a brief dim? Those clues narrow it down fast.
Two questions to ask first
1. How many lights are flickering?
One bulb = bulb or fixture issue. One room = circuit issue. Whole house = service or main neutral issue. The scope of the flicker tells you how far back the problem is.
2. Does it happen when something else turns on?
If lights dim when the fridge, AC, dryer, or a power tool kicks on, it is voltage drop from that appliance's startup surge. If it happens randomly with nothing else changing, the issue is electrical, not load-related.
The 6 causes of flickering lights
Loose bulb (easy fix)
The bulb has unscrewed itself slightly in the socket. The contact at the bottom of the bulb is making and breaking connection. Turn off the fixture, wait for the bulb to cool, and tighten it. If it was the bulb, you are done. If it keeps flickering, the socket itself may be worn out.
LED bulb on an old dimmer
Dimmers made for 60W incandescent bulbs do not work with 9W LEDs. The LED draws so little current that the dimmer can't find a stable load and starts flickering, buzzing, or pulsing. The fix is a modern LED-compatible dimmer (look for "CL" or "ELV" rated dimmers) plus dimmable LED bulbs. A licensed electrician can swap dimmers in under an hour.
Loose connection at the fixture or switch
A wire under a screw has worked its way loose or a back-stabbed connection has failed. The intermittent contact causes the light to flicker and generates heat at the loose point. This is an arcing condition. AFCI breakers are designed to catch it, but if you don't have AFCI on that circuit, the only warning is the flicker itself. A licensed electrician opens the fixture and switch, checks every connection, and tightens or replaces them.
Overloaded circuit
Too many devices pulling current through a single circuit. The voltage sags briefly every time a motor starts or a heating element kicks on. Lights on that circuit dim or flicker in sync with the load. The fix is usually a dedicated circuit for the big load, or a panel upgrade if you are out of breaker space.
Large appliance voltage drop
The AC compressor, well pump, or electric dryer has a high startup current. That surge pulls voltage down briefly across your whole service. Lights dim for a moment and recover. A quick dim on a hot day when the AC starts is normal. A heavy, prolonged dim or one that is getting worse over time points to an undersized service, a loose main lug, or a failing utility transformer.
Failing main neutral (serious)
The main neutral wire is the return path for all the current in your home. If the connection at the meter, the main panel, or the utility pole is loose or corroded, your 120V circuits start seeing wildly swinging voltage. One side of the panel can surge to 180V while the other sags to 80V. Lights on different circuits flicker out of sync. Appliances fail. The neutral connection heats up. This is an emergency call. If lights throughout the whole house are doing odd things at the same time, shut off the main and call an electrician and your utility.
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What you can check yourself
Before calling an electrician, run through these steps. They are safe, fast, and often solve the issue.
- Turn off the light, let it cool, and tighten the bulb. Still flickering? Replace the bulb with a fresh one of the same type.
- If it is an LED on a dimmer, switch the dimmer fully on or replace the bulb with a non-dimmable. If the flicker stops, you have a dimmer compatibility issue and you need an LED-rated dimmer.
- Check if it happens only when an appliance starts. If yes, note which appliance. A short, light flicker is usually normal. A heavy, sustained one is not.
- Note whether the flicker is in one fixture, one room, or the whole house. If it is multiple rooms or the whole house, stop troubleshooting and call an electrician.
When to call an electrician
- Lights flicker across multiple rooms or the whole house at the same time.
- Flickering is paired with a burning smell or warm outlets.
- Lights go bright, then dim, out of sync on different circuits.
- Replacing the bulb and the dimmer did not stop it.
- A specific appliance causes a heavy, sustained dim every time it runs.
- The flicker is getting worse over days or weeks.
Newman Electric covers Vancouver WA, Camas, Battle Ground, Longview, and the rest of Clark and Cowlitz County. We answer 24/7 at 360-828-7143.
Frequently Asked Questions
Why do my lights flicker?
Six common causes: loose bulb, LED on an incompatible dimmer, loose wiring, overloaded circuit, voltage drop from a large appliance, or a failing main neutral. Start with the simple stuff (bulb, dimmer) and move to wiring and panel issues if those don't fix it.
Is it dangerous if my lights flicker?
A loose bulb or bad dimmer is not dangerous. A loose wire connection or a failing main neutral is a real fire hazard. Whole-house flickering that happens without any appliance causing it is the most serious version and should be treated as an emergency.
Why do my LED lights flicker when dimmed?
Your dimmer was designed for incandescent bulbs and can't find a stable load with low-wattage LEDs. Use a CL or ELV-rated LED dimmer and verify the bulbs are labeled dimmable. Newman Electric swaps dimmers as a quick service call.
Why do my lights flicker when the AC or dryer turns on?
A brief flicker when a motor starts is normal voltage drop. A heavy, sustained dim, or one that is getting worse over time, means your service may be undersized, a main lug may be loose, or the appliance circuit is undersized. Have it measured.
When should I call an electrician about flickering lights?
Call if the whole house flickers, if flicker is paired with burning smells or warm outlets, if replacing the bulb and dimmer didn't help, or if the flicker keeps getting worse. Newman Electric takes diagnostic calls in Vancouver WA at 360-828-7143.
What is a loose neutral and why does it cause flickering?
The main neutral is the return path for all current in your home. If that connection is loose or corroded at the meter, panel, or utility, voltage swings wildly across your 120V circuits. Lights flicker out of sync, appliances fail, and connections can overheat. It is an emergency.
Related Services
Electrical Repair
Diagnostic calls for flickering lights and intermittent power
Lighting Installation
New fixtures, dimmers, and smart switches that actually work
LED Lighting Retrofit
LED conversions with dimmer compatibility done right
Electrical Panel Upgrade
For undersized services that cause voltage drop on big loads
Electrical Safety Inspection
Full panel, service, and connection evaluation
Signs You Need a Panel Upgrade
Flickering is often one of them
Lights still flickering?
Newman Electric diagnoses flickering lights in Vancouver WA and across Clark and Cowlitz County. Our crew checks your fixtures, switches, breakers, and service connections, and tells you straight what's going on. Estimate is free.