What Causes Flickering Lights? (And When to Call an Electrician)
Flickering lights can be a loose bulb, an overloaded circuit, or a sign of something dangerous. Here's how to tell the difference — and when it's time to call a pro.
Flickering lights are one of the most common electrical complaints — and one of the trickiest, because the causes range from trivial to serious.
Minor Causes (Fix Yourself)
Loose light bulb: The simplest explanation. Turn off the fixture, let the bulb cool, and tighten it. If it's an LED bulb in a dimmer fixture, make sure the dimmer is rated for LED.
Incompatible dimmer switch: Older dimmers designed for incandescent bulbs often cause LED bulbs to flicker, buzz, or dim unevenly. The fix is a dimmer switch rated for LED/CFL loads — a simple swap that an electrician can do in 15 minutes.
Appliance startup: A momentary flicker when the refrigerator compressor, AC, or sump pump kicks on is normal — these appliances draw a large startup surge. If it's a brief, slight dim that immediately recovers, it's usually not a problem.
Moderate Causes (Schedule an Electrician)
Overloaded circuit: If lights flicker when you use a specific appliance (hair dryer, space heater, microwave) on the same circuit, the circuit is overloaded. The fix is usually a dedicated circuit for the high-draw appliance.
Loose wire connection: A loose connection at a switch, outlet, junction box, or the panel itself causes intermittent contact — producing flickering. Loose connections also generate heat and can cause arcing. This is a fire hazard and should be addressed promptly.
Old or damaged wiring: Homes built before 1970 in Kansas City may have degraded wiring — cloth-covered insulation, aluminum wiring, or undersized circuits that weren't designed for modern loads.
Serious Causes (Call Now)
Flickering throughout the entire house: If every light in your home flickers simultaneously, the problem is either at the main panel, the service entrance, or the utility connection. This can indicate:
- A loose main breaker or bus bar connection
- A failing neutral connection (very dangerous — can cause voltage imbalance and damage appliances)
- A utility-side problem (loose connection at the meter or transformer)
Flickering with burning smell or warm outlets: This is an emergency. A burning smell means active arcing is occurring — which can start a fire. Turn off the affected circuit (or the main breaker) and call immediately.
Lights that dim significantly when AC kicks on: A noticeable, sustained dim (not just a quick blink) when your air conditioner starts can indicate your panel doesn't have enough capacity. Common in older KC homes with 100-amp panels running modern loads.
The Diagnostic Process
When you call us for flickering lights, we:
- Ask questions to narrow the scope (one light? one room? whole house?)
- Check the affected fixtures, switches, and outlets
- Inspect connections at the panel
- Test voltage at various points to identify where the drop occurs
- Recommend the fix — which could be anything from tightening a connection ($100 service call) to a panel upgrade ($1,800–$3,500+)
Call (913) 278-6049 or request a diagnostic appointment online.
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