I live in a townhouse in Chicago. I have a front and back porch. The front porch light holds one bulb, the back one holds two bulbs. For the last six months or so, I haven’t been able to get a light bulb to last more than six weeks in either fixture. This has included plain incandescent bulbs, outdoor floods, and even the hated CFLs. Haven’t tried LEDs yet.
What would cause this? It has been spread over Winter and Spring, so I doubt it’s the weather. I leave them on 24/7, but even so, six weeks seems might fast to burn out a bulb. They used to last half a year or more. Could a bad switch cause this? Bad fixture? Bad wiring? Help! I’m running out of bulbs, and out of patience.
A poor neutral connection at the feed to the breaker box? This will allow the phase A to depress the neutral, producing overvoltage on phase B and vice versa. Do the lights get brighter when the fridge starts, or you are using the toaster or microwave?
You are getting surges, too high a steady voltage, or water or something leaking. I would look for corrosion around the fitting, and waterstains around the socket. If you can’t find any, replace the breaker that goes to the socket. If that doesn’t work, replace the socket-- unless the socket looks really old, then you might just want to assume it’s somehow improperly grounded.
Something that just occurred to me is to make sure you are using the right rated bulb for the socket. If it is meant to have a 40W and you put in 100W, it will burn out right away, probably, or trip the breaker. But if it’s close, like a 75W in a 60W socket, it will just not last, because it will burn hot. It’s dangerous. The socket probably says what it is rated. Don’t go by the breaker. If the socket doesn’t say, and you don’t know, then try a lower wattage bulb. If it lasts, but the light isn’t satisfactory, replace the socket. You can use a multimeter to test the ability of the wires to handle the wattage, or just go by the gauge of the wire, but normally you should be able to assume a house wiring can handle a 100W socket. If the wiring looks funny, like it was installed by a resident after the house was built, maybe you want to call an electrician.
An LED bulb would solve this (if it exists as an issue) as the wattage requirements are notably less for an LED vs a CFL or incandescent for the same amount of light. Do shop around as LEDs are often on sale for large discounts as loss leaders in big box hardware and office supply stores weekly sales (ie staples, lowes, home depot).
I have found LEDs to be more rugged than CFLs for outdoor use.
I was under the impression that those labels only mean that that socket wasn’t designed to handle the heat of a higher wattage bulb.
I’ve run high wattage bulbs in low wattage fixtures for years and have never had a bulb burn out right away or trip a breaker. I have noticed plastic fixtures become brittle and occasionally appear melted.
A 75W in a 60W socket will burn as hot as a 75W bulb in any socket, the rating of the fixture has nothing to do with the heat from the bulb.
Incandescents won’t last long these days, they are nothing like they used to be. Not sure why this is the case. My parents had trouble with a porch light at their home, as I recall because of the front door, the vibration wasn’t noticeable but apparently enough to cause the bulb to go bad in fairly short order. Bulbs sold for “Rough Service” should last somewhat longer. The CFLs are known fire hazards, probably best to avoid these. LEDs work great in porch applications, though the color balance is a little strange. Early ones had that arc-welder ambience, a little spooky for my old-fashioned self.
If they are in enclosed fixtures, they could be getting hot. That will shorten their life.
One fix is to rewire the back porch one (the one with two bulbs) so the lights are in series. Cuts the current in each by half, and makes them last forever. I have floods in the front wired such that have lasted so long I can’t remember when I last replaced a bulb.
I had an incandescent bulb in a fixture on my porch that is over the garage doors. The bulb burned out frequently, I assume, due to vibration. I initially switched to a rough duty (garage door opener) bulb, then eventually upgraded the fixture to LED.