I need to replace a couple of bulbs in my apartment which are controlled by an "old" dimmer switch, which predates the advent of LED bulbs. My understanding is that I cannot use a dimmable LED bulb here, so I'm going for an incandescent. If this is wrong, I will buy LEDs and the rest of this question is irrelevant. (previously it had CFLs, which seemed inappropriate and would flicker)

Bulbs: I got "Ecosmart" dimmable incandescent bulbs from Home Depot. 43W ("60W Replacement"). Natural light (I mention this because a similar model with a different light color has very different warnings on the back, including having an internal Halogen (!) which this does not mention, though it still may have for all I know).

Fixture: My fixture appears to say "660W 250V". (Does that sound right? I'm in the U.S.) so it sounds like I'm well within limits. It's on the ceiling, and it has a cover that I would describe as white and translucent and encloses the bulbs completely. The fixture also has a silver sort of surface above the bulbs, presumably to insulate the ceiling from them.

I can attach photos of either if desired.

My concern is this:

Among the warnings on the back of the packaging is "Suitable for use in open fixtures". However, it does not say "Unsuitable for use in closed fixtures". Should I infer this? Am I in danger of fire if I use this thing with the cover on? (Guy at Home Depot thought it over and ultimately concluded it should be fine, but I want to double-check) Right now I have been using it with the cover off.


  • For future reference: ALL incandescent bulbs are dimmable whether the package says so or not. (N.B.: I'm not sure how much future use this info will have as incandescent bulbs are on the endangered species list and nobody is looking to preserve their ranks and grow the population.)
    – FreeMan
    Feb 8, 2023 at 14:03

3 Answers 3


I think the "660W 250V" reference is to some specific part of the fixture - perhaps the socket. I find it highly unlikely that a US residential fully enclosed fixture would be rated (a) for 660W - that is way too much power == heat and (b) 250V - the ratings for lighting fixtures (as opposed to switches, timers, etc.) is typically for 120V.

Based on the info at Home Depot for this bulb, this appears to be designed for "table lamp, sconce, vanity, pendant" - all of them open. I wouldn't put a 40W or 60W (and this is in between) bulb into a totally enclosed fixture like you describe - that just does not sound like a good idea. In a very quick read of the page, I didn't see a reference to a full manual, but it sounds like "open" is code for "not closed".

In any case, 43W dimmable incandescent makes no sense at all. Incandescent bulbs are the cheapest in up-front cost. But it doesn't cost much these days to get dimmable LEDs. For example, these Cree bulbs also from Home Depot cost a little more but give you:

  • MUCH lower power consumption - 10W vs. 43W
  • MUCH longer life
  • More light - 815 lumens vs. 600 lumens

and specifically list enclosed fixtures.

About the only scenario (a bit of a stretch) where it would still make sense to worry only about the up-front cost and not about energy cost or replacement cost (both vastly lower with decent LED bulbs than with incandescent bulbs - lower energy costs and fewer replacements) is a builder who wants to put in everything as cheap as possible for profit. (And even then, putting LED bulbs everywhere would let the builder advertise the "energy efficient home").

  • I'm not sure you linked to the same product. There was a model there with similar packaging and the same wattage specs, but different color (perhaps Soft White, as you linked). Unlike the one I bought, that one had icons indicating that it was for a table lamp, etc. So I suspect that's the one you're linking to.
    – orblivion
    Apr 22, 2019 at 20:03
  • I wanted to get dimmable LEDs as you recommended. However this circuit is not an LED dimmer circuit. I'll clarify that in my question.
    – orblivion
    Apr 22, 2019 at 20:05
  • (At any rate you've convinced me to use different bulbs here. Coupled with the fact that another commenter said it's actually halogen on the inside)
    – orblivion
    Apr 22, 2019 at 20:19
  • If you owned rather than rented, replacing the dimmer would be a quick & easy solution. But as a rental you generally shouldn't do that for a variety of reasons. A forward-thinking landlord (a rare item) would do the math and realize that in the long run replacing all lighting with LEDs would pay for the cost of replacing dimmers, so it is worth asking the landlord to do that. The landlord will likely respond "no", but you might get either "yes, if you buy a dimmer then I'll have my electrician put it in the next time he's on the property" or "sure, you can do that" - but doing it yourself... Apr 22, 2019 at 23:06
  • may be against local rules even if the landlord says its OK. But it is a simple job to do. Apr 22, 2019 at 23:06

The reason a lot of LEDs/CFLs are not okay in enclosed fixtures is that the heat will eventually cook the integrated electronics, causing premature failure. Incandescent and halogen bulbs are generally okay for enclosed fixtures because even though they get a lot hotter, they don't have anything that cares about heat. You can visually examine the bulb for any electronics; it should be obvious.

That being said, damage to the fixture is also possible. If your home is old at all and uses the standard sockets, the fixture was probably designed to be used with 60W incandescent bulbs, but you should still check. Here, basically make sure the fixture is metal and glass. Any plastic is bad.

In the end, of course, I would strongly recommend buying an enclosed-rated LED light.


What you're up against is the fixture is only rated for a certain amount of heat (before it puts too much heat on the ceiling and threatens to burn the building down). The lamp should have a sticker or marking indicating maximum safe wattage (in terms of power output of the bulb).

This number refers to actual wattage (i.e. 43W) not the nonsense "watt equivalent" number they toss around (60) -- it's high time to stop speaking of "watt equivalent", and state the correct figure -- lumens. However manufacturers don't like lumens, because that means telling the truth. With "watt equivalent" they can fudge the numbers. A 60W bulb should have 800 lumens.

There's nothing eco-"smart" about this bulb. It's a bad old incandescent bulb, just with an internal little halogen bulb to get a tiny efficiency gain. It's not even the same color (2700k) as traditional incandescents, if that's what you're into. Meanwhile LED has gotten past its ugly blue infancy, and you can now buy honest 2700k LEDs that don't dazzle and look like incandescents. They're not the cheapest thing in the store, obviously.

The 660W/250V rating is a standard rating of the edison socket component and does not apply to the lamp as aa whole.

  • This is good general information about modern incandescent bulbs (the bit about all of them having internal halogens was new info for me) but unfortunately unrelated to my question. I've clarified in my post my reason for not getting an LED bulb in the first place.
    – orblivion
    Apr 22, 2019 at 20:14
  • Actually, that was somewhat unfair of me. Your mentioning that it's an internal halogen was helpful to me, it's enough for me to switch to something else (though I'm not sure what).
    – orblivion
    Apr 22, 2019 at 20:23

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