Why Light Bulbs Burn Out

The main reason why light bulbs burn out is regular use.

Standard incandescent bulbs, which make up 85 percent of the world's lighting, tend to burn more quickly than other types. They last from 750 to 2,500 hours, depending upon the brand. Since most homes use incandescent bulbs for several hours per day, the short lifespan causes them to burn out quickly.

Below are some possible causes of light bulb failure. Some of the causes may lead to electrical shorts or even a fire in your home. Remember, electrical wiring is not a hobby! If you don't feel comfortable working on your electrical problem, please don't take chances - call Jake Electric. 

High Voltage in the Home

If the supply voltage to your home is too great, bulbs will generally burn brighter and burn out much faster. To find out, use a voltmeter and check the voltage in an outlet or at the service panel. Usually, you'll like to see a voltage of 115 - 125 volts. Anything more is considered excessive and the utility company should be called to correct the problem. Occasionally this causes problems that are more serious.

Bulbs are Getting Too Hot

Even if you purchased a bulb in the right wattage, your bulb could still be burning out from excessive heat. This is usually the case if you’re using a bulb that is too large for your fixture or when you are using the wrong bulb in an enclosed fixture. Although a larger bulb with the right base type may readily screw into a fixture, a fixture that’s designed to operate a smaller bulb may not be able to adequately disperse heat throughout it. If you think this may be your problem, make sure you’re using the right size bulb for your fixture, or try using a bulb with a lower wattage instead.

Excessive Fixture Vibrations

Another reason your lights could be burning out quickly is that they’re subject to excessive vibration. Fixtures may undergo excessive vibration under a variety of circumstances, but common causes are wobbly ceiling fans or a fixture that’s placed beneath a kid’s room or exercise room. To fix this, consider using a rough service bulb or upgrading to a 130-volt long life light bulb, both of which have thicker filaments that can handle the stress. You may even consider an LED light, since LEDs don’t have filaments to begin with (not to mention they’re more energy efficient).

Bulb Doesn't Light

If a bulb doesn't light even after you've changed the bulb, it's likely that one of the following is the trouble:

  • Be sure that you plug in the cord. Check the cord for damage. If it is, install a new cord. Don't tape the cord and cause future problems.
  • The outlet or the switch controlling the outlet may be defective or broken. Check for voltage and replace it if necessary.
  • Bulbs can be loose in the socket. Tighten the bulb to correct the problem.

Cheap Bulb Don't Last

Sometimes, cheaper bulbs will have little or no solder on the contact point of the bulb. These bulbs will cause you problems and won't last very long. Just because you have a package of four bulbs and installed a new one, doesn't mean that the bulb isn't defective. Try inserting the bulb in another fixture to make sure it works. Next time, buy a better bulb that will give you your money's worth.

Light Bulb Flickers

A loose bulb in the socket can flicker on and off. Tighten the bulb to correct the problem. Intermittent electrical contact can also cause flickering. It's like turning the light on-and-off constantly, and will reduce bulb life. A bad light socket or a poor electrical connection somewhere in the wires leading to the light (most likely right at the fixture) can cause it. Flickering can cause the bad connection to get hot and possibly start a fire. If you don't locate the cause of the flickering and it affects all or many lights, you could have a bad neutral connection -- a bad situation. Another indication of a neutral problem: as larger appliances (i.e., washing machines, dishwashers) cycle, lights will get quite noticeably brighter or dimmer (minor changes in intensity are normal). If you suspect this problem, have either the electric company or Jake Electric to determine the problem.

Circuit Breakers Tripped or Fuses Blown

If the circuit isn't working due to a tripped breaker or blown fuse, then there is likely a short circuit. The cord could be shorted, a plug could be defective, or the light socket is shorted or defective. In any case, replace the defective parts before resetting the breaker or replacing a fuse.

Overheated or Burnt Bulb

Open the fixture globe or cover and check to see if the bulb wattage is too large for the fixture. On the side of the fixture is a label that states the appropriate maximum size wattage of bulb to use in the fixture. A larger size bulb usually will screw right into the socket, but that can spell trouble. Using a larger bulb will cause excessive heat inside the globe and cause the fixture to overheat. Due to the excessive heat, the bulb life will be much less and will likely show signs of trouble. Use the appropriate size bulb. The area where the bulb is in contact with or close proximity to the fixture insulation will likely show signs of this heat.

Recessed or Can Lights Turn On and Off

Some recessed or can lights cannot be covered with insulation. With the heat generated by can lights, they might start a fire. Even though fiberglass does not burn, the covering paper does. Alternatively, the heat build-up caused by the covering insulation will hamper the efficiency of the can light. Either way, the fix for this is to get a sealed or IC-rated light that does allow for close contact with insulation.

Modified Incandescent Bulbs

Some households have elected to use modified versions of the incandescent bulb, which feature a larger tungsten filament and last a bit longer. These types of bulbs still only last around 2,500 hours, so they might appear to burn out quickly as well for people that use lighting heavily. Halogen lighting is another option that uses chemicals and coating to recycle the heat that the tungsten filament produces; they normally last from 2,500 to 4,000 hours. These bulbs can still burn out quickly and might not be the right choice for larger homes.

Fluorescent Bulbs

Fluorescent bulbs are the ideal replacement for all other types of bulbs; they are about 25 to 35 percent more energy efficient and last from 10 to 25 times longer. If you have fluorescent lighting that burns out quickly, then there might be a problem with the ballast. The ballast serves to regulate the electrical current flow to the light.