Fluorescent Lights
These bulbs used to only come as long white tubes ranging from 1 foot up to 12 feet. The new screw-in fluorescent bulbs to replace standard bulbs are becoming more and more useful. Although older fluorescent fixtures only work above 50 F.degrees, they now make new energy efficient fluorescent fixtures with electronic ballasts that are brighter, turn on instantly and work in temperatures down to 20 F. These are great for garage and basement lighting.
Long or circular fluorescent bulbs:
The newer energy efficient fluorescent lights are recognizable by the thinner bulbs (T-8 (8/8ths = 1 in. diameter) vs T-12 (1-1/2 in. diameter). These lights are brighter and whiter than the old bulbs, and use 20% less electricity. Older fixtures can be updated with the new technology ballasts without replacing the fixture.
Older fluorescent fixtures (before 1980) often had a "starter" that looked like a thumb-sized silver can. These are rarely seen nowadays. If you have this type, the starter can go bad and prevent the light from working. A slight counter clockwise twist of the starter should allow it to be removed. Be sure to replace with the same type as is marked on the starter.
For most fixtures, the bulbs work in pairs, inner and outer pairs. (This is not true for the T-8 bulbs mentioned above.) If one bulb goes bad, it will prevent its partner from working. It's a good idea to replace both bulbs at the same time. Also be sure to insert the bulbs correctly. It's easy to not get the pins into the socket correctly, it even happens to us.
Ballasts transform the 120 volts of the house to 300-500 volts needed to work the fluorescent bulbs. If the bulbs are good, and the sockets are fine, then it most likely is a bad ballast. Call us to replace it. (Screw-in fluorescent bulbs have a built-in ballast.)
U-bent bulbs are found in 2x2 fixtures. If they work intermittently, try new bulbs. Don't get the bulbs with the metallic strip along the exterior or the bulb. Although these bulbs normally work fine, if you're having occassional problems with a fixture, these bulbs may be the source.
Generally, you can not use a dimmer with fluorescent bulbs. However, I have seen some recent screw-in bulbs that can be on a dimmer.
Screw-in Compact Fluorescent (CFL) bulbs:
These can be used in almost any regular screw-in bulb fixture. They're save energy and last longer. Great use of these bulbs are where it's difficult or inconvenient to replace bulbs. Installed in post lights, you shouldn't need to worry about replacement for some time.
There is sometimes a choice of the color of the light output: white, soft white, etc.
An important note about the CFL bulbs: some are dimmable, some are not. If you have a dimmer, the bulbs may flicker or make a noise. The packaging and the bulb itself will say whether it is a dimmable bulb.