CFL base down?

[K8MHZ]

Symptom as per HO:

Sconce light on one side of mirror in bathroom is malfunctioning. If you turn on the switch, nothing happens. Then if you tap the fixture, the light comes on. New bulbs did not affect the symptom.

My observations:

The HO was using CFLs mounted base down. If I turned on the switch, no light. If I tapped the fixture once, the light would come on and stay on even if I tried to 'tap it off'. If the switch was turned off and back on, no light and the above was repeatable. I tried two CFLs the HO had, same thing. I stuck a regular filament bulb in the 'defective' fixture and it worked perfectly.

So, we took one of the CFLs and stuck it in a fan fixture to test, base up. The bulb summarily failed, totally this time.

Are CFLs particular to base orientation or did the HO just get a bad batch?

 

[Mr.Sparkle]

Are CFLs particular to base orientation or did the HO just get a bad batch?

CFL's don't care which way you mount them, and are notorious for having what in my own experience has been about a 5% failure or defective product rate, meaning for about every 20 bulbs I install at least 1 is bad out of the package or goes bad within a few weeks.

 

[ceb58]

CFL's don't care which way you mount them, and are notorious for having what in my own experience has been about a 5% failure or defective product rate, meaning for about every 20 bulbs I install at least 1 is bad out of the package or goes bad within a few weeks.

I have ran into the same. Bought a 4 pack of cfl flood lamps. 1 right out of the box had the curly glass tube loose from the base inside the glass cover. Mfg. defect.

I tried two CFLs the HO had, same thing. I stuck a regular filament bulb in the 'defective' fixture and it worked perfectly.

I would question where the HO bought the lamps. There are cheep ones and there are really cheep ones. But I think checking the connections in the fixture would be a good idea.

 

[Besoeker]

We have mostly CFLs in our house.
Some are mounted base up and some base down.
A few are permanently on. Hall, stairs, upstairs landing and a couple of base down units in the lounge. Most have clocked up more than 10,000 hours. When we moved to our present house over three years ago, or energy company provided with a couple. Both are still running, base down, after at least 25,000 hours of operation.

I'm sure there are duds around. Maybe we just got lucky.