Why do my Lights Flicker when the Air Conditioner Turns On?

It is common for lights to flicker briefly when a high-draw appliance like an air conditioner turns on. This happens because the motor’s inrush current draws a sudden surge of power that momentarily dims the lights.

While a brief flicker is often normal, persistent or prolonged flickering may indicate more serious issues, such as:

  • Overloaded Electrical Circuit Symptoms: This occurs when high-wattage devices tax a circuit beyond its capacity. If you have added modern appliances to an older home without a panel upgrade, you may notice these symptoms more frequently.
  • Loose Service Neutral Connection: A loose connection at the main service panel or weatherhead can cause lights to flicker, dim, or brighten unpredictably across multiple rooms. This is a significant fire hazard and requires an immediate inspection by a licensed electrician.
  • Voltage Fluctuations: Repeated flickering when running multiple appliances at once suggests the electrical load needs to be professionally calculated to determine if a dedicated circuit or panel upgrade is necessary.

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