How to diagnose the causes of flickering or dimming lights at or in buildings. If the flickering is isolated to a single fixture, it's usually a straightforward repair.
Keeping an eye out for signs of dangerous wiring can keep you and your family safe. Are Flickering Lights a Fire Hazard? Flickering Light Problem Electrical Question: What would cause lights to flicker and go dim then brighter?
Unsafe electrical circuit breaker or unsafe electrical wire : some brands of circuit breaker may cause flickering lights or may fail to turn off in response to an over-current or short circuit, and may even fail to turn off internally when the toggle is switched to the OFF position. A lamp or light fixture with a loose lightbulb or plug can flicker—that's no big deal. Lighting issues caused by voltage problems and loose electrical wiring are cause for concern. I have some up stairs lights that are flickering, and going dim then brighter. Flickering Lights & Intermittent Electrical Power Loss Diagnose & fix flickering or dimming lights or lost electricity. However, if the problem is spread across multiple light fixtures but contained to a single area within the home, then it could be a circuit issue as well. A situation where the same light or lights are flickering in one area and not throughout the home. Lights Flickering and Dimming in a House Sometimes lights flicker and dim because of a loose bulb or a loose connection in the fixture. More than likely, your dimmer switches were created for incandescent light bulbs, and being in the 21st century, you have upgraded to LEDs that offer the mood lighting you prefer. The circuit the dimmer switch is on can become confused when an LED bulb is being used and can cause your lights to flicker as a result. Not all flickering lights are a fire hazard, but if you have flickering lights in your home or office, they should not be ignored. This does not happen all the time but quite often. Tighten the bulb and/or turn off the breaker, check the wire connections to the fixture and tighten those connections. The most obvious cause of this type of problem is a bad light bulb or a bad connection between the light bulb and the light fixture socket.
Probable Cause: Large home appliances add considerable load to your central circuit breaker, which can cause lights to flicker throughout the house, just as the bathroom light might dim or flicker when you switch on your hairdryer. Lights can flicker for a number of reasons, some of which are harmless and others hazardous. Examples are at CIRCUIT BREAKER FAILURE RATES