Every now and then, you will experience your lights dimming for a moment and then returning to their original brightness. This is often a result of the lights being connected to the same circuit that powers an appliance requiring a large amount of power. The light will sometimes dim for a few moments because certain appliances require more electricity when they first power up. Once the appliance runs for a second or two, power levels will taper off and your lights will return to their normal level. If you have central air conditioning, for example, you may experience dimming lights every time it turns on.
Naturally, this dimming is most noticeable in the evening and at night. It is, however, still noticeable during daylight. If dimming lights bother you, talk with your electrician about adding a circuit to power your high power appliance.
NOTE: If you experience dimming, but have not changed anything in your electrical system, the dimming and power fluctuations may be the result of a loose wire. In this case, make sure that you contact an electrician right away so that they can locate and fix the problem.
Lights Blinking On and Off
The following reasons are the most common causes of lights blinking on and off:
- The photo cell controlling the light is out of adjustment. Try readjusting it.
- It is common for recessed ceiling fixtures to use a thermal protector to make sure that the fixture does not get too hot. When temperatures get too high, it will shut off the light. Try using a bulb with lower wattage.
Lights Not Turning On
There are seven common reasons a light will not turn on. They are:
- You have a bad bulb. This may seem like common sense, but is very often the problem. Try replacing your bulb with one you know works, to see if this fixes the problem.
- You have a broken light switch. It will need replacement.
- You have a broken light fixture. In most cases, it is cheaper and easier to replace the entire fixture. If you do not wish to replace the fixture, it is often possible to fix it.
- You have no power. Please read our page about Power Problems.
- Your timer is set incorrectly, or is broken. Try resetting the time, or replacing the timer.
- If your lights are controlled by a photo cell, the cell could be broken or out of adjustment. Try adjusting or replacing the photo cell.
- Mercury Vapor, High Pressure Sodium and Fluorescent lights all rely on an electrical ballast in order to power their unique light bulbs. If these fixtures hum loudly, smell funny, or just don’t work, you may need to replace the ballast.
Lights Not Turning Off
- You may have a broken switch controlling your light fixture. In this case, it is time to replace the switch
- Your timer may need adjustment or replacement.
- If the fixture relies on a photo cell, it may need adjustment or replacement.
Flickering Fluorescent Lights
Fluorescent lights often flicker for these three reasons:
- When first turned on, fluorescent lights will often require some time to warm up. This is more noticeable on cold days, and just requires that you wait a few minutes.
- Your bulbs are old and need replacement.
- Your ballast is old and needs replacement.
Bulbs Burning Out Too Quickly
Bulbs typically burn out for one of the following three reasons:
- You are using bulbs with too much wattage. People will frequently place bulbs of 75 watts or higher into a fixture that is only rated for 60 watts per bulb. As a result, your light bulbs will burn out more quickly than if you had used the recommended bulb size. Try using bulbs of the correct wattage.
- You are using low quality light bulbs. Replace them with name brand bulbs.
- Unknown lighting problems. In this case, your fixture can appear as if it should be working just fine, but not even an electrician can figure out what’s wrong with it. In this case, you will just need to replace the fixture.
The following problems are typical causes of humming lights:
- Bad transformer or ballast. The ballast or transformer will need to be replaced.
- You may have a conflict between your low voltage dimmer and the light fixture that it is controlling. Although it is hard to tell if this is the problem, you might try several different dimmers out in order to find one that won’t make your low voltage light transformer hum.