Alternative oven interior lamps?

[Halcyon]

My oven has three halogen interior lights, they are just the small two-pin "push in" type (12 volt from memory).

I'm having to replace them every 2-6 months (presumably because they just get too hot). All that sits between the bulbs and the oven cavity is a plate of glass.

Is anyone aware of better quality bulbs that might be able to stand up to the hot conditions and last longer? Alternatively, is there such a thing as an LED replacement for this application?

[Cyberdragon]

LEDs in an oven?

*knee slap*

[Halcyon]

LEDs in an oven?

I know you can get LEDs rated to high temperatures, typically 120-130 degrees Celsius. I just didn't know if a more specialised technology existed?

I didn't think the question was that silly?

[Rerouter]

You stuck with incandescent types unless you want some really horrible crap being let out on whatever your cooking,

If the bulb is 12V, then replace it with a bulb 2-4 times the wattage in double the voltage rating, It will last much longer. as the device internally will be operating at a lower voltage.

[Halcyon]

If the bulb is 12V, then replace it with a bulb 2-4 times the wattage in double the voltage rating, It will last much longer. as the device internally will be operating at a lower voltage.

Thanks. That sounds like sensible advice. I'll have to check, it's either 12v or 240v. It's a GY4 type bi-pin base (I don't know if it's actually GY4 or some other variant), but they generally only come in low-voltage versions from what I commonly see.

If I increase the wattage though, won't it put more load on the transformer/circuitry?

[Rerouter]

bulbs are not linear so the rule of thumb gets a bit tricky. so lets work on plain resistances as an example

12W @ 12V bulb, should be 12 Ohms, so draws about 1A @ 12V
48W @ 24V bulb, should be 12 ohms, so draws about 2A @ 24V

Run that 48W bulb on 12V and you end up with about 12W of light, but with a greatly over-rated bulb, the light output will probably be under 12W due to the lower temperature, but you can see why my recommendation works.

[NiHaoMike]

I suppose LEDs might be possible if you can distance them from the heat and use optics to bring the light inside. But since the heat from the halogen bulbs isn't wasteful in that application, an easier solution would be to drop the voltage to something like 80% of original. Won't look that much dimmer but will last a lot longer.

[Andreas]

Hello,

do you use normal halogen lamps or special 300 degree Celsius resistant halogen oven lamps?

https://www.amazon.com/Halogen-oven-lamp-capsule-tolerant/dp/B07CVLLJRX/ref=sr_1_fkmr0_2?keywords=special+halogen+oven+lamp+osram&qid=1582438627&sr=8-2-fkmr0

with best regards

Andreas

[Alti]

I suggest tweaking with bulb wiring.
Put a resistor in series.

[Electro Detective]

I buy oven lamps in pairs, hoping one will last for ages (2 to 5 years) with a backup on hand,

or if they are crap, I shop for a another brand and buy a pair of those, and repeat the above

I keep the packaging on the good ones, and pray I can still get them
and pray even harder they came from the same manufacturer 

I don't think the current LEDs and or their electronics will cope with oven temperatures,
especially on a six hour cooking marathon of baked foods, cakes, frozen pizzas, PCB board reflows, 7018 electrode dry outs.. 

That all said, maybe another globe in series somewhere else might work so you have a hope of a dimmer but longer lamp life,
assuming the main oven lamp doesn't get 'cooked' anyway 

[jogri]

You stuck with incandescent types unless you want some really horrible crap being let out on whatever your cooking,

If the bulb is 12V, then replace it with a bulb 2-4 times the wattage in double the voltage rating, It will last much longer. as the device internally will be operating at a lower voltage.

That would work with normal incandescent bulbs, but i am not sure if halogen lamps would survive that for long as they absolutely need the high temperatures to operate: they rely on the tungsten iodide inside the lamp to deposit onto the hottest part of the lamp (the filament), breaking apart and forming new tungsten on the filament-> it repairs itself.

If you run it way below its nominal wattage, i am not sure if this process kicks in enough to counter the normal decay of the filament. It could work, but it could also fail much faster as it is ironically not hot enough for the lamp to operate properly (the oven doesn't make a difference since this process needs over 1200°C).

[steve30]

No recommendations unfortunately, but I'm surprised you have to replace your oven lamps so often. My oven uses a standard tungsten "oven bulb" which usually lasts years.

[Red Squirrel]

That got me thinking, wonder what IS the alternative?  Surely they are going to stop making incandescent bulbs soon, if they haven’t already.

[coppice]

My oven has three halogen interior lights, they are just the small two-pin "push in" type (12 volt from memory).

I'm having to replace them every 2-6 months (presumably because they just get too hot). All that sits between the bulbs and the oven cavity is a plate of glass.

Is anyone aware of better quality bulbs that might be able to stand up to the hot conditions and last longer? Alternatively, is there such a thing as an LED replacement for this application?

Are you buying the bulbs that are specially made for ovens? Standard bulbs won't last long, but the specially made ones are usually fine..... unless, perhaps, your oven has poor thermal design.

[Electro Detective]

The sockets can get crusty over time and or not screwed in properly etc so not be making enough full contact with the globe, and or arcing on every start up.

I've swapped out a crusty one that also sported a cracked glass dome, been good for a few years

They should be checked every few years and spares ordered way before, as parts may never be available again just when you need them

[Whales]

I bought some cheap replacements from eBay a while back, but they blew within a month or so.

I suspect that "microwave oven" and "oven" types might be having their terminology blurred by sellers.

[thermistor-guy]

My oven has three halogen interior lights, they are just the small two-pin "push in" type (12 volt from memory).

I'm having to replace them every 2-6 months (presumably because they just get too hot). All that sits between the bulbs and the oven cavity is a plate of glass.

Is anyone aware of better quality bulbs that might be able to stand up to the hot conditions and last longer? Alternatively, is there such a thing as an LED replacement for this application?

What brand of bulbs are you using? They might be Chinesium specials, designed to fail quickly.

My oven uses an incandescent lamp, which has lasted for many years. Recently a service tech replaced the lamp, and I had a look at it before he installed it: Smeg brand, made in Italy, still in production, rated at 300 deg. C (from memory).

Oven lamps are exempt from legislation that phase out inefficient lamps with low lm/W, like incandescents and halogens, for practicality. These lamps are still in production.

The filament temperature is critical. As a practical matter, for long life, you want as low a colour temperature as you can get.

Aircraft incandescent lamps rated at 2E5 hours operate at 2000 Kelvin filament temperature. At 2000 K, tungsten has a vapor pressure that is just measurable - in other words, it's just starting to evaporate. Above 2000K, the evaporation increases dramatically.

Another other wear-out mechanism is grain recrystallization. As the filament heats and cools, its grain boundaries reform, and start aligning with each other (instead of interlocking). This makes the filament more fragile - more likely to break because of thermal or mechanical shock. To reduce this effect, long life filaments use Rhenium tungsten which has a higher recrystallization temperature. But these are more expensive - another reason to avoid Chinese "bargains" and go with a geniune spare part from a decent brand.

http://www.tlt.co.jp/tlt/english/products/industrial_light/miniature_lamp/catalog/info.htm

So, TL;DR: go for a decent brand and low colour temperature.

[tooki]

Is anyone aware of better quality bulbs that might be able to stand up to the hot conditions and last longer? Alternatively, is there such a thing as an LED replacement for this application?

You realize the only reason we have moved away from incandescent bulbs for general illumination is because they waste 90+% of their energy as heat? And you realize that in an oven, that makes an incandescent bulb essentially 100% efficient? Using ANYTHING else makes zero sense.


I do agree with everyone that you must make sure you're using bulbs specifically sold as oven bulbs. Ordinary ones will not stand up to the oven environment. DO NOT run halogen bulbs below their rated voltage, as jogri said. (It's OK to do so part-time, but they need full-wattage operation at least some of the time.)

That got me thinking, wonder what IS the alternative?  Surely they are going to stop making incandescent bulbs soon, if they haven’t already.

Incandescent is only banned for general lighting. They remain fully legal for decorative and specialty applications.
Halogen is a more efficient subtype of incandescent, and is subject to different regulation, which is why they're still widely permissible.

This isn't going to change any time soon.

The filament temperature is critical. As a practical matter, for long life, you want as low a colour temperature as you can get.

Aircraft incandescent lamps rated at 2E5 hours operate at 2000 Kelvin filament temperature. At 2000 K, tungsten has a vapor pressure that is just measurable - in other words, it's just starting to evaporate. Above 2000K, the evaporation increases dramatically.

Except that this applies only to regular incandescent bulbs, and not to halogen bulbs. They are designed to run at higher temperatures and will fail sooner if they aren't allowed to run properly hot long enough. Since the OP's oven uses a halogen bulb, going for a lower color temp is not advisable. (Not that I recall ever seeing different color temp variants of halogen bulbs. Incandescent yes, but not halogen.)

[thermistor-guy]

...

The filament temperature is critical. As a practical matter, for long life, you want as low a colour temperature as you can get.

Aircraft incandescent lamps rated at 2E5 hours operate at 2000 Kelvin filament temperature. At 2000 K, tungsten has a vapor pressure that is just measurable - in other words, it's just starting to evaporate. Above 2000K, the evaporation increases dramatically.

Except that this applies only to regular incandescent bulbs, and not to halogen bulbs. They are designed to run at higher temperatures and will fail sooner if they aren't allowed to run properly hot long enough. Since the OP's oven uses a halogen bulb, going for a lower color temp is not advisable. (Not that I recall ever seeing different color temp variants of halogen bulbs. Incandescent yes, but not halogen.)

No, it applies to both. Going for a lower colour temperature (strictly, lower filament temperature) is still advisable if you have the choice. Halogens generally run hotter simply because they are designed to be brighter (to a human observer). The filament needs to be hot enough to dissociate the tungsten halide, but the dissociation temperature depends on the halogen fill gas - it can be below 2000 K, in which case you don't need a filament much hotter than 2000K, thereby promoting a long lamp life.

[james_s]

Halogen lamps do indeed fail more quickly if you run them too low. I remember back when those halogen torchier lamps were popular I often saw people leave them on dim for extended periods and the whole "bulb" would turn black in as little as a few hours. You'll probably extend the life if you drop the voltage slightly but if you go down too far it will get shorter. The bulb wall *must* reach sufficient temperature for the halogen cycle to work. The most common cause of short bulb life is cheaply made low quality bulbs. Next is probably a tie between excessive vibration and excessive voltage.

There's really no alternative to incandescent for a high temperature application like that except for maybe HID, but that comes with its own set of problems.

[jogri]

Next is probably a tie between excessive vibration and excessive voltage.

Hmm, that could also be the cause if the oven fan has aquired an imbalance and isn't shock-mounted properly.

[Electro Detective]

Fan blades may/will get sticky gunk build up, especially on the back where you can't see it, or get to it easily.. 
and any uneven imbalance and the weight of the gunk will cause vibration and noise,
vibrations that don't do heated and or aging or a cheaply made globe filament any favors, halogens even less so.

Fans with little or no easy access are a pain to scrape and clean properly without deforming them, but it's either get it done
or blow money on a new one eventually after it has overworked itself to premature motor failure,

add the cost of 'mystery globe fails' along the way too.. 

[thm_w]

You realize the only reason we have moved away from incandescent bulbs for general illumination is because they waste 90+% of their energy as heat? And you realize that in an oven, that makes an incandescent bulb essentially 100% efficient? Using ANYTHING else makes zero sense.

Yes and no. Microwave ovens have started moving to LED bulbs. Regular ovens will move to LEDs at some point.
Its just a matter of who can figure out how to implement them well (as nihaomike mentioned), design a high temperature LED, or can advertise it as a new unique feature and sell well.

Using a higher efficiency (and therefor brighter, with the same given circuitry and wiring), makes a lot of sense when the lighting in most ovens is quite poor.
Not to mention the downside of a single point source light, if you have it on the top, and have a tray, now all the light to the next level is blocked.

[james_s]

I mean you could do it right now if you really wanted to. The double layer IR coated glass used for the oven door reflects a remarkable amount of heat back inside, the outer face of the glass is usually not too hot to touch while baking. An LED on a fan cooled heatsink behind a coated glass lens would probably be just fine. It would cost considerably more though for questionable gain. The bulb in my oven is the only incandescent lamp I can think of that I still have in service in my house. It's not used enough for energy to be an issue and I think I've had to replace it once in 10 years or so.

[thermistor-guy]

Halogen lamps do indeed fail more quickly if you run them too low. I remember back when those halogen torchier lamps were popular I often saw people leave them on dim for extended periods and the whole "bulb" would turn black in as little as a few hours. You'll probably extend the life if you drop the voltage slightly but if you go down too far it will get shorter. The bulb wall *must* reach sufficient temperature for the halogen cycle to work....

The bulb wall must be hot enough (say over 250 deg. C) so that any condensed tungsten on the wall combines with the fill gas to form tungsten halide. The filament must be hot enough to dissociate the tungsten halide and reduce net evaporation from the filament. But if both constraints are met (i.e. halogen cycle is operating), increasing the filament temperature still further, say to 3400 K, will reduce its life.