Expert Electric Blog

Why Do My Lights Flicker?

We often get asked by a lot of our customers this question: Why do my lights flicker? Here are a couple of questions you want to ask or observe first to get to a possible resolution.

  1. When do the lights flicker? Is it when a large appliance is on, such as air conditioning or heat pump?
  2. Is it all the lights that are currently on in the house or the same light/sets of lights that always flicker? Try to notice and make note of which lights specifically if it is not all the lights in the house.
  3. How often does it occur? Again, try to make note of which lights flicker.

Here are some answers that might help.

Same light or lights flicker in the same area and NOT in the entire home:
This problem can occur from simply having bad light bulbs to a bad connection between the light bulb and the light fixture socket or a more complex troubleshooting issue like a loose wire in that particular circuit. Locating a loose or broken connection will require a complete circuit diagnosis to find what could be causing the issue. A licensed electrician will have the tools and expertise necessary to help you with this.

Lights throughout the house and/or nearly half of the lights in the house flicker:
If you are noticing random lights flickering and sometimes nearly dimming throughout the house or a large part of the house and you are sure it’s not the result of a large appliance, make sure you have an Electrician look at your main electrical service. The issue could be a corroded connection at the meter base or in the panel. Also, the main breaker could be defective or the incoming overhead wires could be severed or worn.

Lights flicker when a large appliance (air conditioner or heat pump) kick on:
If your lights dim slightly this is normal. It is common with large loads like air conditioners and heat pumps to cause lights to dim. Why? These appliances can draw up to one hundred or more amps for that few seconds that that they start up. The large motors in these units draw a very large amount of power the moment they start and will continue until they get to full speed. The power draw will drop off once the motor reaches operating speed; this usually takes 1-3 seconds. Dimming can be mild or more prolonged depending on conductor size of the appliances, distance from the city transformer that feeds your home, and the electrical characteristics of the appliance’s motor. If your lights dim AND flicker then you should get this resolved. This could be as a result of a bad or loose connection somewhere and this usually gets worse, not better.

Finally, if you have flickering lights and you home has aluminum or older “knob and tube” wiring, shut that circuit off at the breaker and do not turn it back on until you have had it resolved. We would be happy to help you with this. Remember flickering lights is never a good thing because flickering means electricity is arcing (sizzling) somewhere (and arcing means heat and fire). In our experience these situations always get worse as time goes on. Our advice is to get it fixed as soon as possible! If you hear sizzling or arching this also should be addressed immediately. Shut the circuit off and call your local expert electric immediately.