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Are your LED light bulbs burning out too soon?

LED light bulb

LED light bulbs have a tendency to make grand claims about their lifespan – it’s common to see manufacturers promise bulbs will last 25,000 or even 50,000 hours. But we’ve found many failing well before this.

One of the attractions of LED light bulbs is that they’re supposed to last a long time. And so if you’re shelling out for these bulbs – typically more expensive than other types of light bulb – you’ll want to be sure that they’ll live up to those claims.

But our tests show that not only do many LED light bulbs stop working before the end of their promised lifespan, some don’t even reach the soon-to-be-implemented EU minimum lifespan of 6,000 hours. We discovered bulbs from both Ikea and TCP that failed to reach the 6,000 hour mark for the majority of samples we tested.

Ikea bulb among failures

In the tests – which were carried out by Which? and our European partner organisations – we took five samples each of 46 different bulbs. The bulbs were switched on for two hours and 45 minutes, then switched off for 15 minutes, in a continuous cycle until they burned out.

Five different bulbs stopped working before the 6,000 hour mark for the majority of samples we tested, though the TCP and Ikea bulbs were the only ones which were sold in the UK. Both have since been discontinued.

New EU regulations which will come in from 1 March 2014 say that 90% of any batch of LED light bulbs should last at least 6,000 hours.

Another five bulbs stopped working before the 10,000 hour mark for the majority of samples we tested, despite claiming lifespans of at least 25,000 hours. None of these bulbs were sold in the UK.

In total, 66 of the 230 samples we tested failed before the 10,000 hour mark, though they all claimed they would last at least 15,000 hours.

Has your bulb burned out early?

Ikea said the bulb had passed its own tests and those in a third-party lab. It’s looking into why the bulb failed our test and has removed it from sale in countries where it was still available.

TCP said it was already aware of the problem with this bulb and withdrew it from sale when they discovered the problem. TCP added that it no longer deals with the supplier of that particular bulb and now make their LED bulbs in-house.

We’re in the process of testing the life span of many more LED bulbs, and we’ll update you if we find others that burn out prematurely. But we also want to hear from you – have you bought bulbs that haven’t lasted as long as they should?

Comments
Member

A Luxeon data sheet http://www.luxeonstar.com/assets/downloads/rd07.pdf shows the effect on life of increasing junction temperatures – where the LED chip is mounted. In fact it seems that 25 deg C is the normal ambient for giving performance characteristics.

LEDs have life defined in two ways – the point at which a certain % of them fail (usually 10% and 50%) and the point at which the light output has fallen to an “unacceptable” level – usually 70%. This data sheets shows combinations of these two. although for coloured LEDs the principals are for LEDs in general.

Putting your LEDs in a ceiling below a loft seemingly increases the ambient by 10 deg C and as the graphs show this can halve their effective life. However, that means the LED was working right on its temperature limit in the first place in a normal ambient. It illustrates the need to use good quality LEDs that are not overstressed under normal operation and have good thermal management. Nevertheless, even halving the life for a decent LED still gives of the order of
20 – 30000hours (for most of us 20 years life) – so it does not explain the rubbish performance of the others.

Member

My understanding is that the junction temperature of a LED relates to the semiconductor and not the interface with the mounting/heatsink, which will be considerably cooler.

I think it is unhelpful to rate the lifetime of LEDs or any other lighting in terms of years because this will vary according to use. Old fashioned bulbs were generally regarded as having an expected lifetime of 1000 hours, and if anyone wanted to work out what that corresponded to in years they could do that on the basis of their planned use.

Is there evidence that different brands of LEDs perform significantly better than others? I have seen evidence on Which? Conversation and elsewhere that even the well known brands are failing prematurely.

Member

The junction temperature is on the LED chip and cannot easily be measured directly. It is normally calculated by measuring the temperature on the thermal mounting pad and taking account of its thermal resistance. It is the temperature that determines the performance of the light-emitting chip (but not, of course, of the electronics used to operate it which will cause failure if they get too hot).

I’m not sure how many people relate thousands of hours to how long in months or years they might expect a lamp to last in normal use. Generally it is taken that in the home 1000 hours is about a year’s use. But it will depend where it is installed of course. The point about LEDs is tthat 20000 hours say might be 20 years to put it in perspective; but that takes no account of the life of the electronics used to run it – and their life, even with a good LED chip, might be much less..

Member

I appreciate that the junction temperature is difficult to measure, but the lighting industry should have chosen a different term for the temperature of the mounting pad rather than hijacked an established expression. There are other examples of confusion being introduced in this way.

Expression of life of lamps in years became commonplace with CFL lighting, choosing some arbitrary daily use. Ask the public and I’m sure that they would prefer lifetime rated in terms of thousands of hours rather than based on years of operation based on 2.7 or 3.7 hours’ use per day (I cannot remember which).

It seems clear to me that current designs of LED lighting are overheating both the LEDs and the control electronics – hence we are seeing premature failures with both cheap and expensive brands. As we have agreed the best answer is to have separate LEDs and electronics, as in non-domestic lighting. I would have expected the well known brands not to produce direct replacements for existing lighting, but when there is a profit to be made, that takes priority.

Is there any brand of LED lamp (designed to replace halogen or old fashioned incandescent bulb) that can be relied on to achieve the claimed lifetime? I think not – but am prepared to be proved wrong.

Member
Phil - NSW Australia says:
17 January 2016

Linear flouresent tube lamps seem to soldier on in all kinds of heat but are terrible when cold until they warm up , and not as efficient as LED and use nasty heavy metals. We are having major issues with led’s overheating in Australia and failing. I am pushing suppliers for standards to advise consumers and installers the max ambient temperature and airflow recommedned to achieve the quoted lifespan .This allows for fitting design and installation locations to cater better to allow for the temperature rise at the LED itself and the electronics contained within the LED lamp or housing.

Member

With linear fluorescent lamps, the control electronics are not in a confined space and separate from the lamp, so that overheating is not a problem. The amount of mercury is small and the tubes generally have a long life. As you say, fluorescent lamps, including CFLs, don’t do well in low temperatures.

With LED and CFL bulbs it can a significant difference if they are operated cap-down or cap-up, the latter more likely to cook the electronics. I think you are right that we do need to be given advice about how to use lamps to reduce overheating. The real answer is to have the lamp separate from the control electronics, just like fixtures for fluorescent tubes.

Member

Phil -if the Australian external ambient temperature is much higher than countries like the UK and in summer it is . Then exporters should increase the aluminum heat-sinks on the bulbs to cope with this . If it is a case of the driver section overheating -ie – capacitors drying up/ active components overheating then a re-design is required or a higher standard -ie- industrial quality used . I cannot believe that any industrial concern in Australia or anywhere else would put up with low quality lighting requiring frequent replacement . I think we are back to – built to a cost , do you have large imports from China as you are near to it geographically ?

Member

wavechange, the junction temperature is the key temperature in the performance of the LED chip and is therefore used by the chip manufacturers in their data sheets. It is not difficult to measure in the industry. So lighting manufacturers should make this measurement – the chip manufacturer gives the information on how to do this – to ensure under normal operating conditions the maximum junction temperature is not exceeded in their product. They will also need to check other electronic components of course.

Member

I think we can agree that there is ‘rubbish’ on the market, as you put it. I question whether there are any brands of LED replacement bulbs that can be expected to last, on average, for the lifetime predicted by the manufacturer. The early LEDs were promising, but these were much lower power than many of today’s offerings.

Member

I expect the LED chip manufacturers do specify the reliability data based on junction temperature but it is up to the bulb manufacture to produce reliable products that take this data into account. On the few examples I have seen it is the LED’s themselves that have failed but I think this is because there is inadequate heatsinking to maintain a reasonable temperature on the LED junctions. Additionally the designs I looked at also produced a good deal of heat from the support circuitry which dissipated in the same heatsink as the LEDs.

A major factor is also that the whole bulbs, when used as an incandescent bulb replacement, are often used in a poorly ventillated place (e.g. surrounded by a glass lampshade) that prevents good air circulation. Of course the ventillation requirement is never stated when marketing the bulbs and most people would think that replacing a 60W incandescent with an equivalent LED bulb that only dissipates about 9W would not be problematic. However this is important. An incandescent bulb fails because of the life of the filament, which can be at around 2500C, eventually fails. Because the temperature is so high, the surrounding ambient varying by a few tens of degrees does not matter too much. With an LED the life falls off significantly above 85C and rapidly above 125C. It is quite likely that many lamp fixtures that do not allow good ventillation will cause a temperature rise at the LED to exceed these temperatures. Their life will also be affected by the ambient room temperature. A few tens of degrees can be very significant.

Examples I looked at had poor heat sinking to start with and “heat conductive plastic” surrounding the aluminium heatsink though not bonded to it. I doubt these bulbs would meet the stated life requirement in any surroundings.

Member

Grums – I am still using a light fixture with 60W golf ball bulbs because of the risk of overheating either CFL or LED lamps in the small shades. It’s not used much and I have a few spare bulbs, so I will carry on using them, though it would be good to switch to low energy lighting.

I have read about poorly constructed LED lamps where thermal paste has been poorly applied or absent, so that the efficiency of the heatsink is compromised.

Member
allen says:
30 July 2015

Just had two Cree 3 way LEDs burn out after a few months use. Purchased at Home Depot. This looks like very poor quality and warranty is a sham. Don’t purchase this brand.

Member

I measured 94-97C on the plastic body of Philips bulbs. Junction temperatures are much higher. Max junction temperatures in datasheets range from 130C to 150C and I bet these bulbs are getting close to that. Plus i think your bulbs are brighter right after turning them on opposed to 15 minutes later as LEDs drop in efficiency the hotter they are. Current LED technology is pushed over its limits.

Member

Yes Mark – the hotter they get the lower the efficiency but some of that is down to the pushing of the limits of the actual LED in terms of supply current . In other words ,to get the most profit cheaply each LED is run on its maximum current rather than under run . As in electronics a diode is only limited in its current carrying capacity but LEDs used for consumer lighting have a limited current capacity, unless we are talking expensive industrial types for specialised applications.

Member
AggieGreg says:
11 June 2015

I put an Osram 8.5W LED bulb in a table lamp in my living room on 10/1/14. It burned out on 6/10/15. I keep this lamp on in the evenings, but it’s always off by bedtime, so it couldn’t have had more than 1,200 hours, just shy of its promised 25,000 hours.

Member

Another example of a well known brand failing prematurely.

Member

But is it statistically significant? One swallow does not make a summer 🙂 If we are to rate brands for durability – and someone should – then you need to take larger samples to begin to sort out those that are likely to last well from those that won’t. I’d like to have confidence in durability before I think of investing in a currently shaky energy-saving technology.

I imagine other consumer organisations throughout Europe are looking at LEDs. Have Which? co-operated with them to get a larger pool of more meaningful data?

Member

That’s the problem Malcolm. We don’t know. People are more likely to post if their expensive LED bulbs fail. What I object to is the extravagant claims that are currently being made for the lifetime of LED bulbs. I keep seeing examples of premature of with well known brands, for example: amazon.co.uk/Philips-MyVision-929000200801-Watt-Shape/dp/B005OYW6SG Philips LED bulbs generally do better than this for reliability, but it provides an example of why buying a particular brand might not be a clever thing to do.

I recall you mentioned that you had under-cupboard LED lighting. Here the control electronics is separated from the heat-generating LEDs, though there is a greater risk of radio interference if the wiring is not shielded.

Member

The way the LEDs are arranged in a strip keeps them cool. I checked for both FM and DAB interference and there was none even when the receiver was very close. I’d still choose mainstream brands if I was going to purchase, or maybe high street retailers own brands like Diall, simply because if I had a problem I could contact them directly and persistently if necessary. I don’t know how well Amazon would deal with this for example.

Member

I prefer to buy in local shops because it is easier to take faulty goods back and explain problems. I generally buy well known brands but larger retailers are selling some respectable products at affordable prices. You are not paying as much for advertising and fancy packaging. I have been impressed by Tesco spiral CFLs.

Many of the products on the Amazon website are sold by their Marketplace traders, often unheard of companies that few would go near if it was not for the Amazon name. I have not bought electrical goods from Amazon for some time, but as part of an experiment, I bought a travel adaptor costing about £1.90 and was sent an item that looked nothing like the photo on the Amazon website. After exchange of correspondence, including photos, I sent it back and received a refund, but was out of pocket by £2.80, the cost of return postage. The Marketplace trader ignored my requests and Amazon would not provide a refund because I was not buying directly from Amazon.

Member
allen says:
30 July 2015

sound like two 3 way Cree LEDs used a little in lamps since 11/14. Poor quality in more than one brand.

Member
Paul Vivash says:
10 May 2016

According to “Which” Diall LED bulbs top the list. One of mine lasted less than a month.

Member
EL CHEAPO says:
25 July 2016

My OSRAM 8.5W LED bulb from Home Depot was over the stove in the vent fan. It lasted 279 days. Used about 10 hours a day ….. or 2,800~3,000 hours. Longevity and economies were the reason I shelled out more money for the bulb. Received neither. Always write the start date on the bulb. Even fluorescent bulbs don’t last their 5-7 year claims.

If you place a small solar yard lamp near the bulb you get a nice interior night light. One is on a lamp shade hoop and lights up the ceiling all night.

Member
Buchu says:
13 July 2015

Cree bulbs are horrible. They are supposed to last 10 years – I have several that went out after a week. The replacements I received aren’t any better as they are failing too.

Member
allen says:
30 July 2015

Same here. They are junk and a sham. Home Depot store in Palatka, FL acted like they could care less. I have returned one to Cree so far no response. $4 to mail plus a $21 bulb-this is light robbery!

Member
Jen woodrow says:
16 July 2015

I’ve replaced almost all of the light bulbs in my house with LED. The kitchen has 5 canned lights, 2 of which are the original “junk” bulbs. Well, one just died and it wasn’t one of the remaining “junk” bulbs, it was one of the new $15 each LED, it didn’t even outlast the builder grade bulb! I’ve spent a small fortune getting rid of these bulbs that seem to last longer than the original. Oh yeah, one has died already in the bathroom too. I’m thinking it’s all just a scam for an increase in charges!!!

Member
allen says:
30 July 2015

Had two Cree 3 ways die in lamps after a few months service. Bases were very hot. Strange! We have a consumer sham on our hands sponsored and encouraged by gov law. We need to let the firms selling this junk know the results. Home Depot folks just passed me off when I told them about the poor quality.

Member
Buchu says:
2 August 2015

Flee from Cree! They have a 10 year warranty but YOU have to pay shipping to send them their dead bulbs. What good is that?

They also have a T8 bulb recall – these are sold at Home Depot:

http://www.cpsc.gov/en/Recalls/2015/Cree-Recalls-LED-Lamps/

I’ll NEVER buy anything with the Cree name on it again!

Member
easypayment says:
9 August 2015

I bought an OSRAM 60 watt A19 less than 6 months ago and it burnt out a few days ago. It says 22+ years life on the box! I got a new one that I’m going to return. I’m giving up and letting everyone else be the Guinea pigs on LED light bulbs.

Member

An update for you: Ikea has announced that it will sell only LED bulbs by September. The first major retailer to stock only LED bulbs, Ikea says that the decision is based on helping customers live more sustainably, without sacrificing style.

http://www.which.co.uk/news/2015/08/ikea-to-sell-only-led-light-bulbs-413603/

Member

I wonder whether they will give proper guaranteed life and freedom from interference (radio) from LEDs? I have a mixture of LEDs, halogen and CFLs for appropriate lighting in appropriate places for good reasons and I’ll be sustaining that policy.

Member
hafsa says:
29 August 2015

good your totaly write