There are a number of reasons that the lights in your home could be flickering or dimming. Some of the reasons (for dimming) are common and not of major concern. However, flickering lights can be a sign of a serious problem in your home's wiring and a real threat to the safety of your family. This blog is for informational purposes only. If for any reason you believe you have an electrical issue, contact a licensed electrician immediately.
Although we cannot cover every cause of flickering and dimming lights in this blog. I will try to cover the most common causes / solutions and the difference between a typical "brown down" (dimming) and flickering.
A browning down (dimming) of lights is caused by a reduction in voltage, usually due to a large load being introduced into to the electrical system. For instance, when your furnace kicks on (a motor load), the lights dim briefly. Or when you plug in the iron in your bedroom (a resistant heat load) the bedroom lights dim or "brown down". In an older home this is fairly common, because the original electrical system was not designed to carry the appliances we consider common today. If you have a home built in 1955, that electrician probably did not account for a microwave in your kitchen, a television and computer in every bedroom, etc. If the electrical system is wired and functioning properly, this type of brown down could be little more than an annoyance, because the breakers or fuses should prevent you from overloading the circuit and damaging the wiring. Usually, to eliminate this problem in an older home we would have to update or add circuits in the home to reduce the load on each circuit and account for high load items.
Dimming lights can be an issue in newer homes as well. Although modern appliances have been accounted for in newer homes and codes have changed to require adequate circuits for these higher loads; the wiring of rooms and the number of rooms put on each circuit is still pretty much at the discretion of the electrician wiring the home. In a very competitive new home market, some electricians may try to minimize the number of circuits they install to save costs. This can lead to a similar problem as in an older home, with the use of high load (mobile) appliances such as vacuum cleaners. Also, even if the electrician installed an adequate number of circuits in the home for general lighting and power, the placement of these breakers in the panel can affect the circuit. All of the larger load and appliance circuits should be installed at the top of the panel or nearest the main breaker / line side of the service panel. If a high load item is placed near the bottom of the panel, it will pull current through the buss of the panel. As the resistance passes through the buss it will affect the voltage on all of the breakers it passes by.
If you have an issue with dimming lights we can schedule an evaluation and recommend solutions to the problem.
Flickering lights, meaning, actually coming on and off, on their own, a strobe affect or flashing, are almost always indicative of a loose connection and a potential life threatening situation. The connection could be loose anywhere along the circuit. If it is one or two rooms it is most likely in the switch, a nearby receptacle, a junction box or in the panel (breaker). If it is affecting multiple rooms it could be an issue with the main service coming to the home, the meter housing, or the main line or main breaker feeding the panel. If you have flickering lights you should contact a licensed electrician immediately and have the problem evaluated.