Answer:

This would be the #1 question ever asked. Other variations of this question include: "When The Furnace Turns On", "Microwave", "Washing Machine" or other equipment that dims the lights for a brief period of time.

Identifying the cause of dimming lights and determining the extent of the problem can be time consuming.
Our CurrentSAFE® Standard Home Electrical Hazard Detection Service INCLUDES testing and documenting the conditions for all of the following possibilities:

Low voltage
Loose connections
Under sized wiring
Resistance problem in wiring
Phase imbalance
Circuit breaker malfunction
Overloading of circuits

Other issues found that are beyond our Standard Service testing procedures include:

Failing motors or internal wiring issues in appliances or heating and air conditioning equipment.
The quality of power provided by the utility company. NOTE: This does not always mean that the utility provider is obligated to rectify the problem. Utility providers have acceptable limits and tolerances that allow some fluctuation.

It will be necessary to experience the dimming event to identify the problem. When we have completed our service, we will provide you with a report detailing our findings. We will review the report with you and discuss your options.