Lights Flicker When the AC Starts? What It Usually Means
Many homeowners notice lights dim or flicker briefly when their air conditioner starts. While a small dip can be normal, excessive flickering may indicate an electrical issue worth investigating.
Common Causes
- High Startup Current
AC compressors draw significant power during startup.
- Weak Capacitor
A failing capacitor makes the compressor work harder to start.
- Loose Electrical Connections
Loose terminals create voltage drops.
- Undersized Electrical Service
Older homes sometimes struggle with modern HVAC loads.
- Utility Voltage Issues
Occasionally the problem originates outside the home.
- Aging Compressor
A hard-starting compressor can create noticeable light flicker.
- Shared Circuits
Poor wiring design can cause lighting circuits to be affected by heavy loads.
Warning Signs
Call an electrician if:
- Lights dim dramatically
- Breakers trip
- Burning smells occur
- Flickering worsens over time
Final Thoughts
A slight flicker when an AC starts is often normal. However, excessive dimming may indicate capacitor problems, wiring issues, or a struggling compressor that deserves further investigation.
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