Possible causes
- High equipment starting demand
- Undersized or deteriorated connections
- Circuit or supply issue
Safe checks before you call
- Note which rooms are affected and whether the issue is new or worsening.
- If there is buzzing, burning smell or a hot outlet, stop using the affected equipment and call for help.
Professional assessment: A qualified electrician should evaluate the affected circuit, equipment and protective devices before the issue is treated as resolved.
When it may be urgent
If you notice smoke, burning odors, sparking, heat or shock, stay away from the equipment and call for qualified help; call emergency services for immediate danger.
FAQs
Why do my lights dim when the air conditioner turns on?
The AC starting load can cause a brief voltage change. New, pronounced or widespread dimming can also indicate an electrical supply or connection issue that deserves professional evaluation.
What should I tell the electrician?
Note how long the dimming lasts, which rooms are affected and whether it occurs with other appliances. Avoid opening the panel or handling energized wiring.