/ Home & Energy, Technology

The energy-saving LED bulb that switched off the radio

An LED bulb lighting up the darkness

We get sent some weird and wonderful tales of products going wrong, but one story piqued our interest so much that we just had to send it to the lab to test it out. Can you help us shed more light on the mystery?

Last year we received this intriguing message:

‘I recently changed six halogen down-lighters to more energy efficient LED bulbs. Unfortunately when the lights were switched on, the DAB signal on my radio was wiped out!’

To try and figure out this conundrum, we sent a batch of cheap, generic 12V LED bulbs to our lab and found that when a digital radio was placed within a few metres of the switched-on bulbs the signal went fuzzy. When the radio was placed within a few centimetres of the LED bulbs, it cut out all together.

The plot thickens

LEDs are ultra energy efficient light bulbs that can last up to twenty years and have been hailed as the future of home lighting.

It seems our members are not the only ones who have had this problem. There are other accounts of LED bulbs affecting radios, with AVForums also collecting stories. Nick Tooley shared his experience:

‘I had the same problems with LED bulbs wiping out DAB reception and tried several types of bulbs, but to no avail.’

And it seems that the issue may not just be limited to digital radios – TVs may also be affected. After fitting LED down-lighters in his kitchen, Jackord noticed the following problem:

‘While the lights are much better, we then by accident noticed that the digital TV would not work (I was complaining that we had no reception at all, did not make any sense, began to think that there had been some sort of catastrophic disaster which stopped the TV stations from broadcasting…lol) then someone turned off the ceiling lights in the kitchen and, hey presto, on came the TV.’

Shedding light on cheap bulbs

So what bulbs are affected? We tested three 12V generic LED bulbs and we also compared them to branded 240V GU10 LEDs and some halogens. We found only a very minor interference with our radio signal. So at this stage, the issue seems to be limited to cheap knock-offs rather than branded goods.

We’ve only done preliminary tests on this problem, so can’t make any concrete conclusions on why this is happening or how widespread this bizarre problem is.

That’s where you come in. We need your help – have you had this problem? If so, please enlighten us in the comments below, including what model bulb you were using and where you bought it.

Dave - TheRetiredPhyicist says:
28 October 2016

It is an inherent propert of a semiconductor PN junction (including the junction in an LED) , that it creates radio noise when energised(technically pink noise as the noise is not constant strength out to infinity, if it was it would be white noise). This is from the fundemental physis of semiconductor materials. And the only thing you can do is keep the aerials of TVs and Radios away from such devices. If commonsense prevails som time post-BITEX they will be banned and we can all revert to incadecent lamps along with coal fired power stations, and pull down all the eye-sore wind-mills now polluting the English skylines.

All well and good Dave but the large scale RF interference is being caused by cheap filtering and components in the SMPS , as well as deterioration due to overheating of passive filter components -C+R confined in less than ideal cramped conditions /noise generation of resistors/ capacitor ESR changing due to overheating , even exploding in some cases.

That’s different from the general view that the electronics in LED lamps and the drivers used for low voltage lamps are the source of interference. If the problem was semiconductor noise then why do some LED lamps produce severe interference whereas others create no problems?

Bang on Wavechange and he also says its pink noise , I am looking at a simple 70,s circuit diagram using a reversed bias zener diode as a white noise generator .

Do you know if a white noise generator produces frequencies as far as those used in FM and DAB radio, Duncan? I remember circuits for white noise generators when I was younger, but never build one.

Yes Wavechange but you need digital iC generators to amplify the circuits . I am looking at a 10Hz to 18Ghz broadband noise generator in the US commercial electronic engineering field but we are talking university test lab prices ( car prices or more ) . Under the conditions of an LED light there is nowhere near the power generation /amplification factor to make LEDs generate this , the LED,s are at the end of the chain of electronics not the input side which is the SMPS , they do not have the ability to act like a massive transmitter their junctions would be destroyed by a massive input of signal . If it was reversed and the SMPS with a large Mosfet was at the output fed from LED,s at the input which are amplified by the Mosfet -yes it could do this . Small circuits at 5 Mhz bandwidth can be built using zeners reversed biased not LED,s

It’s not Pink Noise (I’ve swept rooms with pink noise for equalization efforts) and it’s not White Noise. It’s just trashy, overdriven static being produced by a cheaply designed power supply.

I am not arguing with that Ed.

Some of us have been disappointed that Which? has not paid more attention to radio interference in their tests on LED bulbs. I am pleased to report that we have not been ignored and the April 2016 issue of Which? magazine has advice on how to get better DAB reception (page 58). This includes the suggestion: “Turn off LED lights”. 🙂

The other suggestions are more practical.

Swapped my 50w halogen bulbs in kitchen downlights today for 3w MR16 LED bulbs branded THG ( trading hub global ). DAB radio in kitchen and garage no longer work, loss of signal. Contacting supplier of bulbs.

They say LED bulbs are being fitted to the F35,s bought from the USA to block Russian air-to-air missiles targeting them —– just kidding MOD !

Ed Rodrigues says:
10 December 2016

I installed 4 Lohas 3 Watt LED bulbs on my outside lights on a timer. I can tell when they come on as the reception on my High Frequency Amateur Radio goes almost full scale. The bulbs don’t indicate that they’re FCC Certified and they radiate RF energy in the High Frequency Radio Band. No, it’s not my timer – I checked.

Good to see another SWL like myself Ed , its one advantage of short wave communication receivers you can pick up the fundamental frequency plus harmonics showing the full range of the radiation unless you have a spectrum analyser with RF head input. nearly full scale in “S” units ?

Electron1948 says:
20 December 2016

What about FM radio interference, just as much a problem! I have a perfectly good FM radio in the kitchen (until that is the LED lamps go on) The lamps wipe out Radio 2 but seem to leave Radios 3 & 4 largely unscathed, this puts paid to the idea that it’s white or pink noise as it only seems to straddle Radio 2, even though the antenna is a good distance away on the other side of a cavity wall. The culprits? 6W Megaman LED with a CE mark on the packing

FM interference hasn’t been missed Electron1948 -if you have the time I commented on the frequency range further back in the convo and many others have mentioned it. the worst interference shown on an RF spectrum analyser is in the FM band -approx- 89Mhz to 108Mhz but it all depends on the bulb due to component variables producing different fundamentals and harmonics stretching up to 200Mhz .Radio 2 frequency on FM is 89Mhz-91Mhz so its in the range .Oregon DOT(Dept. of Transport ) in the USA have drafted a list of radio interference from LED traffic lights completely knocking off FM radios within 50-75 feet -14 inches from a flashing LED and they used profession scientific equipment. Getting even more impressed with Which even US lighting companies are quoting Which -what next -Which Global ?

Carl fradley says:
26 December 2016

Not having a vast electrical knowledge ,I get what your on about but is there a fix or would I need to change all my leds as all my room switches with leds in them and all different brands knock off the TVs for a split second or sometimes just the audio
Cheers Carl

Carl-LED,s in themselves are not naturally RF generators , many decades ago an enterprising electronic designer posted an article in a now defunct electronic magazine about the transmission of audio frequencies via a sealed in array of led,s ( no electrical contact ) in a metal box this was for an audio frequency generator for use in hi-quality audio testing . I built one and it worked. If it generated interference it could not be used .This was the theoretical basis for an opto-isolator , I often wondered if he became a millionaire . What I am saying is LED lights are not naturally large noise generators it is the power circuit attached to them to make them function , in my time everything was analogue transformer fed , now , to save industry VAST sums of money everything ( well almost ) is SMPS -switched mode power supply – this allows for miniaturization to the end that they are now accommodated directly into the bulbs . By their very design nature they operate (switch power ) at high frequencies , so they are natural noise generators. Combating that are the suppression circuits they need to be designed with their components (active + non-active ) to a high quality of design after laboratory tests and ,yes they are “capable ” of suppression of RF generated interference . BUT — then we have “commercialism ” like very many other means of life on this planet -money-greed-avarice steps in and so you are sold SMPS that i have taken apart -looked at -and then said a prayer of exorcism over as the components were that evil (cheap ) Its the quality of components that vary the intensity in a range of frequencies. Your best bet in the year -2017 is to buy a cheap RF detector ( wide-band ) there are small hand held ones available and go round your bulbs testing them for interference but seeing how one innovations defects help another commercial company there are actually ones advertised for EMF radiated interference , these used to be cheap as they were called wide-band RF detectors but not now -they are called -EMF detectors the price has shot up (like the interference ) , your best bet is to buy a small “bug detector ” as our modern spies dont need to implant them they now have control off all communications by other means so the price has gone down. This gadget will last for years.

Nicholjo says:
30 December 2016

We have just installed a new kitchen – with new LED lights throughout. We were about to buy a new DAB radio, until my son happened to say their DAB radio stopped working when they replaced a few bulbs with LED. Upon finding these Which? Conversations I see that there is clearly a general incompatibility between LED lights and DAB radios that has been known about (though not by me) for several years.
Up until now I have never seen any warnings about the effect of LEDs on radios, whether in relation to LED sales or radio sales.
This is an impossible situation for the consumer, whether technical or non-technical persons.
What has been done by Which? , Industry or Government to resolve it?
FM or analogue cannot be terminated until it is resolved. If not:-
Are we to replace all our LEDs? This would cost me many £100s plus extra ongoing electricity costs.
Or have all DAB radios to be replaced by FM or analogue tuners? Again at ridiculous costs.
Both options run counter to current policies.

Nicholjo- Long time ago there used to be a GPO Radio Interference Group that would have prosecuted the offenders (companies selling RF interference rubbish ) –this was disbanded , reformed as an ineffectual body as- quote- it was “hindering Commercial business concerns ” . This is called political “progress ” I personally knew an employee of that group when BT+GPO were still joined together , I was told this was going to happen as well as BT+GPO being “restructured ” -IE-policies and operations changed , he was transferred to the new group but wasn’t happy about it so got transferred to another department in the GPO . This is what we are left with -great sounding names but in practical terms -“castrated ” .

I think the Radio Interference Group was disbanded long before LED lamps became common and officially recommended. By the time of its demise most domestic appliances were effectively suppressed against interference and most radios and TV’s were capable of withstanding any minor interference. Although DAB radios have been around for about twenty years or more now LED’s are more recent and rather expensive; it would be ridiculous to expect people to revert to other lamps now that they have made considerable investment in LED’s. I have no technical expertise in this but cannot believe there is not a technical solution to the problem so that interference is filtered away from the receiver. I am not over impressed by DAB radio but we have two of them and both do work satisfactorily close to LED lamps. Whether it is due to the quality of the lamps or the quality of the radios I cannot tell.

Just a point John , while it might be called the RIG it didnt just fover normal electrical interference it covered radio transmission interference -IE- radio “hams ” radiating harmonics due to bad transmitter tuning bandwidth , they were even forced to go round their neighbours fitting suppression units to the TV,s that were affected which did broadcast on frequencies in the old days that were near the DAB frequencies now , if they didn’t they could lose their licenses , so they covered RF transmission by a transmission device of any sort and prosecuted those CB users using illegal extra channels that overlapped general coverage of the Short Waves instead of the fixed 27Mhz band . By the way you are right John it is possible to filter the worst RF generation away but it costs money.

I have now seen many examples of LED bulbs that do not cause DAB or FM radio interference provided that the receiver is a metre away from the lamp. It’s asking a lot to expect a radio to perform well if it is beside a lamp, say at a bedside, and the same applies with CFL lamps, where the gas discharge produces short range interference in addition any generated by the electronics.

Many years ago I was suffering from FM radio interference and contacted the BBC for help. An inspector called round, confirmed that the problem was caused by a neighbour’s TV and they had it replaced free of charge. The BBC website offers help for those suffering from radio and TV interference and here is advice for anyone experiencing a problem with LED lighting causing problems with DAB reception: http://www.radioandtvhelp.co.uk/interference/rtis_radio/LED_lighting

It seems that replacing 12V halogen bulbs with LEDs is the main problem, and that is something we have discussed several times on Which? Convo. Replacing MR16 lamps with mains voltage ones such as GU10s may help.

It’s the difference in the current load Wavechange , LED bulbs don’t use as much current so the peaks of emf radiation are higher because of the lighter load on the transformer in 12V circuits .

Thanks to duncan lucas for your explanation of how we have got into this farcical situation over the incompatibility of DAB and LED. Sounds par for weak political oversight.
Just about every new lighting system that I see now is LED – to “save the planet” (reduce carbon emissions) – yet DAB moves in the opposite direction, requiring more power.
I hope someone or some ‘body’ up there realises that FM and Analogue will have to stay around for decades more.
(PS: I like the, probably apocryphal, story of the young girl who was taking an unusual interest in climate change issues. When asked by her grandfather how come she was taking such political interest she responded “we must save the planet, because that’s where I keep all my stuff”. )

It’s worth persisting with LED lighting, Nicholjo. If the bulbs cause interference, just return them for replacement and make sure the retailer is well aware what the problem is. Many have recommended buying a single bulb for testing purposes before buying a bunch of them. If the radio signal (DAB or FM) is weak, you are more likely to have a problem. Some areas are better covered by FM and others by DAB, which is one reason to carry on broadcasting both. I’m in the highlands of Scotland at the moment and FM radio has always been poor here, but the DAB signal strength improved greatly a couple of years ago.

Whilst talking of LED’s there is this article from EDN talking about the way LED’s are sold and the claimed lifespan

” Within an LED bulb the internal generation and distribution of heat is such that it “desperately” needs access to cool surrounding air. The fact that it has that metallic housing is irrelevant in restricted air.

That 60 watt Wal-Mart bulb, when operating base down in open air and not even using a shade, has its internal LED case at 85°C, the absolute upper end of what is considered “safe” for full life expectancy. The same deal is true for competitive bulbs. Put a shade around it… and it’s a little warmer. Put it into any kind of base-up socket and it gets a lot hotter and all life expectancy numbers are off the table. Put it into any kind of porch or post light fixture, and it can fry, with its internal power supply components at the cliff edge of failure. Put the lamp in a ceiling-mounted fully enclosed fixture and set the timer for when failure will occur.”

Proper dissipation of heat from the electronics and chip is necessary for decent life (and light output) of an LED lamp, usually done using heat sink material in well-designed lamps. Instructions on where the lamp can be used should also be given. Unfortunately many lamps are cheaply made without proper regard to cooling, with cheap components, and who reads the instructions (if there are any). I’d choose a well-known lamp maker first off – Osram, Philips for example – and steer clear of unknown brands; by no means foolproof but a good start and someone to approach if you have a lamp that doesn’t last.

That LEDs work well is seen in all the road lighting that has been converted – relatively high power units in hostile surroundings. Here the heat sinking is part of the design, where LEDs and the fixture are considered and tested together, and the electronics are usually separate. We could do the same with domestic LED lighting; we never did with CFLs so unlikely it will happen with LEDs. We’ll just muddle on with the low-cost solution and complain about short life (oh, and interference) from the cheap “bulbs” we choose to buy. Perhaps Which? could look at this (may need expert help).

Malcolm -When you say “expert help ” do you mean government investigators into importers importing ” built to a price ” bulbs ? it cant be SMPS design engineers as their quality designs are good , The engineering philosophy here is well know right across the design board , in very high quality audio electronics , in which, I think, I have some knowledge , you start with a well proven design , not necessarily down to diminishing returns of THD /IMD / Transient distortion /etc but how it sounds , taking into consideration that the power supply is part of the hi-fi chain unless you’re design has excellent power supply rejection of noise / AC ripple /etc . After that you get down to components which in my view make or break a good sounding amp , in that respect I am a follower of English electrical engineer – John Linsley Hood who placed great emphasis on them even drawing up tables of the audio quality of passive and active components . Those components are naturally dearer than the standard ones. The same applies to SMPS -the importers sell to the retailers, the retailers then pay the advertising industry who make them sound like “manna from heaven “- and you buy – “built to a price” goods –time they came clean, both electrically and morally !

No, I mean from people who are knowledgeable about LED lamps. I don’t expect the people at Which? to be experts in any product; they should know the people who are – which includes the reputable manufacturers and trade associations, independent reputable testers, standards bodies, so we can receive advice on what is best to buy.

You know you are asking a lot malcolm , what you are looking for is a professional in the industry to hold up his hand and say–public buy XYZ product because ABC product is crap , I wish you luck , is there anybody out there qualified or working in the lighting industry , and I don’t mean retailers , I mean manufacturing industry who will come on Which and “spill the beans ” ?

I think messages like “buy XYZ product because ABC product is no good” are exactly what us subscribers expect from Which?

Well we do have US experts prepared to spill beans so why not use them?

I have no doubt that commercial LED luminaires are seriously good and designed for long-life. When I was looking after properties the cost of replacing failed units was always a consideration if you had to employ a contractor. Lifespan was a paramount aim.

And yes have Which? failed to grasp the nettle and come clean on what the big problem is? My brother is fitting tiny LED’s under his kitchen cabinets in a shallow area about 15mm deep. Hmmm.

BTW brand names are no indicator of quality if one believes consumer reports as Que Choisir do not rate some Philips bulbs. They have published a report after the first three thousand hours with several bulbs and up and down positions.

Even they seem not to be preaching the heat or the DAB problem …. or perhaps the DAB problem does not exist in France??

I would hope, very much hope, that any problem we have here is checked against what might be occurring with EU consumers.

I am not as cynical as some who seem to assume all manufacturers are cheats who will foist anything onto us as long as it makes them money. Reputable manufacturers invest heavily in making products better and it is in their interests to try to expose rubbish competition. Trade associations help in this and between them publish much information that is helpful. Weeding out the “independent” reports is worthwhile, and reviewing the international standards that look at safety and EMC for example helps understand the problems and solutions, but it needs people with expertise to put this together in a form useful to the “man in the street”. Which? can fulfill this role. “Spill the beans”? It is not a conspiracy.

I would have more confidence if some of the manufacturers had not entered the market for direct replacement of old fashioned light bulbs and focused instead on producing new fixtures designed with longevity in mind. If that has happened, I must have missed it. The manufacturers often claim fabulous lifetimes for their LED lamps yet don’t have the confidence to guarantee them to last for five or ten years.

The consumer market looks for direct replacements – saves the inconvenience and cost of replacing light fittings. A bit like the argument for cheap domestic appliances. However, the energy savings would not have been made without replacement “bulbs” and many of them work perfectly well.

Lamp manufacturers are rarely fixture manufacturers in the domestic market – its a completely different operation.

It would be interesting to see real lifetimes surveyed rather than branding “the manufacturers” as all the same. Many rubbish (and cheap) LEDs are imported – and there is a reason they are cheap, like other cheap products. Hence my suggestion Which? consults experts so we get the facts on which we can base decisions about what to buy.

Which? tests have not identified problems with radio interference and I don’t recall their tests identifying makes/types that were much worse than average.

I’m fairly new to LEDs but have not seen one that is not imported. I seem to be supporting China by buying lamps made by well known manufacturers or sold by well known retailers.

In both CFL and LED lamps, the control electronics tends to run too hot for reliable operation. It is very disappointing that modern light fixtures are still designed for use with LED lamps designed to replace old fashioned bulbs. Maybe those who manufacture household lighting fixtures could have a look at commercial designs and then we could all enjoy LED lighting at its best.

Malcolm – I have an Osram lamp that causes radio interference, whereas the much cheaper ones from B&Q are fine.

Decent LED and CFLs do not overheat the electronics – you cannot generalise like this. You can buy purpose-designed LED and CFL light fittings; just look on line and in the shops. However many don’t want to replace their existing lights – perhaps cost, getting in an electrician – hence the huge demand for light-bulb substitutes. I’ve a lot of CFLs working quite happily in existing, suitable, light fittings – open, enclosed, cap up, cap down. Excessive interference is not only caused by poor quality electronics, but can be down to the installation – wiring lengths and runs for example; EMC testing is done with standard wiring layouts.

I have some Philips LEDs that run far too hot, in my opinion. I accept that there is a demand for direct replacements for old bulbs but the majority of domestic light fixtures on sale still do not separate the LEDs and electronics.

For standards to be fit for the purpose they need to accommodate that wiring installations vary a great deal.

Perhaps you would measure the temperature and let Philips know – they might provide some useful information. A photo of how you are using them would help.

From memory the test represents a sensible wiring installation, which is why it is part of a standard.

I’m sure that this and other companies know exactly how hot their lamps run. On other Convos we have had numerous complaints about poor durability and I am not surprised.

An engine might last for 100,000 miles or more in a car but a stressed engine in a F1 car might not make it to the end of the race.

When I put a Philips lamp in a circuit with dimmer designed to control incandescent bulbs it failed after around 30 minutes and I suspect that it had been running hotter than normal. The rest are working fine and not causing radio interference on FM or DAB.

They will know exactly how hot they run. It will be relevant to the life of the electronics, the chip and the light output among other things. Some companies will overrun lesser quality chips to increase light output at the expense of life, but reputable companies are unlikely to do this. If you have, presumably, measured a temperature on your lamps then you can see whether this is within the manufacturers specification by asking them. Tell them where, and under what conditions, you have measured the temperature. Then you’ll maybe find out if they are running too hot.

Philips list a whole range of dimmers and their compatibility with their LED bulbs http://images.philips.com/is/content/PhilipsConsumer/Campaigns/LI20160421-GB-Dimmable/LI20160421_001-Consumer_LEDlamps_Dimmer-en-GB-2016_04.pdf

Other information http://www.philips.co.uk/c-m-li/led-light-bulbs

Not all LED lamps are dimmable.

Malcolm I am in awe at your faith (loyalty ) to the business world .I admire loyalty but for a number of reasons I have zero faith in most businesses.

Yet you are frequently a defender of BT? Quite right – you have first hand experience. I have been in manufacturing and have first hand experience of a number of manufacturing companies in that “world” and base my comments on that experience.

However, I try to pass on information and my opinion, not to convince sceptics, but to point people to places where they can maybe find something useful to help. The dimmer site provided by Philips seems useful for someone planning on putting LEDs on an existing circuit, or planning a new one. The information on a range of LED “bulbs” might be useful to some. Surely this is one function of a Convo? is surely about

I have a bookmark to information about dimmers and LED lighting provided by Philips, but I don’t recall seeing any useful information provided on the packaging of their lamps.

I defend BT if they are in the right malcolm , did you read what I posted about BT Mail and its American run email service as being the “pits” . It still is, every time i condemn businesses or HMG I get a pretty good repro of a BT email asking me to “log-in ” to MY BT , this shows this service has zero virus protection in its server unlike Yandex Mail which has and blocked it before it got near me and Which has some good blocking facilities . I have also received the dreaded -123 time call charge of which I am paying BT to block as well as Premium cost calls I am waiting to talk to a BT rep as to why that is possible if it is blocked . So although I defend BT I do criticize it too , I cannot for the life of me understand why BT dont have its OWN email service.

None of my slowly growing collection of LED lights seem to upset any of my FM radios; I do not own any DAB radios.

I get the impression that older LEDs were more of a problem, Derek. Since I became interested in the problem I have discovered some early adopters that went back to incandescent lighting.

At my previous house, I was quite an early adopter of LED spotlight bulbs (i.e. c.2008) and did not see any problems.

We even had one of those new fangled DAB radios there. We seldom used it, but when we did, we certainly didn’t see any inconvenient interference from the three LEDs that were on more or less all the time or any other sources.

Derek P – as I have said in posts and made it plain , it depends on the SMPS components themselves as to what frequencies have the highest fundamental frequencies and then you have the harmonics which ,if the fundamental is around 100Mhz ( FM ) which is near the peak of the spectrum analysis readings then a x2 harmonic would be in the approx centre of UK digital broadcasting of approx 176Mhz- 220Mhz .The strength of the harmonic in power is directly related to the fundamental strength of signal power , you are either lucky in your pick of bulbs or you have some type of built in house suppression either lessening the signal or blocking it or the directional aerial in your FM receivers picks up the main FM transmitter at an angle which is 180 degrees from the LED transmitted RF noise . This means of blocking out adjacent signals was used to good effect in WW2 in radio transmission direction finding -IE- it would “null ” out adjacent signals by use of a rotational aerial this type of aerial system is still used over a wide variety of the RF range.

Duncan, I guess I have just been either lucky or prudent in my choice of (i) LED bulbs and (ii) FM radios. I certainly don’t have any sophisticated interference suppression technology.

Most of my LED lamps were off-the-self technology purchased at B&Q, Sainsbury and Homebase in the spring of 2012, just after I moved in here. A few have also been added in recent months, typically from either Sainsbury or Morrisons.

Now that intrigues me Derek .

I have bought own-label LED lamps from Tesco and Sainsbury as well as Philips lamps from John Lewis when buying new light fittings and subsequently. I have not had any problems with any of them. My priority has been to replace halogen lamps first even if they have not failed, then any remaining incandescent lamps, and finally CFL’s. I have been especially pleased with integrated LED fittings I have had installed in bathrooms. Although LED lamps are very much more expensive than their equivalent incandescent bulbs I think the energy savings and the much longer life [which saves a lot of inconvenient replacement work] more than compensate. My only complaint is that there does not seem to be any equivalent to the traditional 100W lamp, at least in an acceptable size and shape.

Alarmed by shop prices, I think a lot of people are sure they will get a bargain by buying on the internet, but unless they are buying a recognised brand they are more likely to be disappointed. Even recognised brands bought in shop can disappoint but at least you can take them back to the retailer for a remedy.

Your right to be alarmed at shop prices John i got one of those gadget booklets through the door with so called bargains you buy by mail order , the exact same halogen bulbs I bought from a UK lamp wholesaler for £15 /10 were being sold for £25/10 and a happy new year to you and the “team “

I’m sorry – I should have phrased that second paragraph more clearly, Duncan. Personally, I am not alarmed by shop prices as that is where I buy all my lamps and I think that the competitive market keeps prices at a reasonable level given that the consumer has the backing of a decent retailer in the event of a fault. There is a price on reassurance. It is also convenient in that I can examine them in the shop and consider alternatives. I can also pick them up in one’s and two’s whenever I wish without having to factor in delivery charges, search a website, do an order, go through the payment rigmarole, and then await delivery and the risk of damage or failure. Mail order from catalogues is not much different and the ‘bargains’ are usually not what they seem.

I agree with John here – I’d much rather place my custom with local shops and I don’t mind paying a little bit more to “de-risk” and “de-hassle” the work of procurement.

Please cancel my complaint about not being able to buy an LED equivalent to the traditional 100W lamp, at least in an acceptable size and shape [my previous post but one above]. I have found that Philips make one and it looks alright although I haven’t bought one yet.

On the question of prices of LED lamps to replace other types, I have just had a failure with a halogen capsule in a three-branch ceiling fitting. Replacing all three has cost £39 [John Lewis today]. If I had bought like-for-like halogen replacements the cost would have been £4.50. The new lamps are by Calex from the Netherlands. The ‘warm whites’ are rather too dull but at that price I shall not be in a hurry to replace them with a ‘colder’ version. One of the problems with converting to LED’s remains the expensive trial-&-error involved to get the right type of lamp and the right fitting. I am more than ever convinced now that fully integrated LED fittings with high lumen values are the way forward with dimmers fitted at the switch. The problem of premature failure remains however and with integrated fittings the entire assembly has to be replaced.

They should still pay for themselves in around 3 years John, providing they last that long. I’m sure JLP will replace them if they don’t.

I agree that fixtures designed for LEDs, preferably with separated electronics, is the best way to get long and efficient life – providing they are from reputable manufacturers. Perhaps Which? could do a report on integrated LED light fittings.

Yes, Malcolm – the lights are on for long periods in the room where I replaced halogen capsules with LED’s which is why I thought the cost was worth it. The original capsules were already installed when the light fitting was purchased and I suspect were inferior quality – the one that failed had a very bright but rather short life and I expected the other two to come out in sympathy any day now with low natural light levels on most days and short daylight hours. I am hoping never to have to climb up to change the lamps ever again. What LED’s are not given credit for is the reduction in the number of accidents that occur from people changing light-bulbs.

Tammy Q says:
14 February 2017

My situation is a little backwards in that we have had LED lights in the house for a few years but have only recently switched from a dish to an antenna for television reception. At first we could not figure out why 2 of our stations would periodically become very unstable. It did not take long to realize that these two stations are the only VHF stations that we have (the rest are UHF) and the only time we have this issue is when someone turns on the garage lights. Keep in mind that the rest of the house has LED lights too so it’s obviously the fixtures we have in the garage. I do not have details on the fixtures yet but I will be getting a ladder to get that information because I am determined to understand this. I cannot believe with more people becoming ‘cable cutters’ that this will not become a much bigger issue.

In common with other electrical products, LED lighting is required to comply with standards regarding how much radio and TV interference they are permitted to produce. The fact that some people do have interference problems demonstrate that the standards are either inadequate or there is a compliance problem, possibly both. If garage lights are causing a problem, that indicates severe interference. I have read of cases where people have had problems with interference with lights in neighbours’ houses.

It would be worth testing the light fixtures individually in case there is a problem with a rogue fixture. Failing that I suggest you ask the retailer (if the fixtures are recent) or manufacturer to replace them because they are clearly unsatisfactory.

Many people reply to the fait accompli of LED bulbs having a much reduced life instead of an advertised long one and the right answer was quoted apart from cheap components – HEAT was a problem . Now its obvious that those who thought up this idea originally And those who implemented it -IE-commercial interests – live on different planes of physics . As you know I have read and bought electronic magazines from a young age but we only have to go back to -2008 to read technical comments on small LED,s where the SAME principles apply -achieving maximum brightness- which in LED,s= maximum forward brightness -quote- the maximum current will depend on the AMBIENT temperature and will DECREASE at HIGH temperatures -eg-above 50 degrees C –and– for HIGH POWER LED,s operation at maximum brightness MAY require a —–HEATSINK . Now you have to ask yourself if this was know at least 8 years ago + WHY do manufacturers ignore it ??

The drive for still higher light outputs from more efficient LED chips does mean higher currents and therefore keeping the electronic components and the chip junction at an acceptable temperature. Metal heat sinks have been, and are used to dissipate heat but also design changes, such as flattened shapes introduce by Philips, can avoid the cost of a heat sink. Worth looking at the major manufacturers sites to see how they appear to deal with heat. Other less reputable manufacturers will not necessarily have the expertise to research techniques, nor be prepared to spend on effective heatsinks.

I hope Which?’s forthcoming report on LED bulbs will look at both their initial and life performance and the consequences of using them in “real life” applications – in typical luminaires for example – to see whether they overheat and whether they cause radio interference.

Overheating of electronic components in CFL and LED lighting has concerned me for years. In the case of LED lighting the problem is being addressed by newer designs that keep the heat-generating LEDs away from other electronic components. One obvious example is the ‘filament LED’.

There is little scope for redesign of LED equivalents of the small GU10 and MR16 halogen lamps that are popular in kitchens and bathrooms. My solution would be to design LED fixtures in which the LED(s) and electronics are not crammed together and sell these to replace existing fixtures. Many existing fixtures could usefully be replaced anyway because they are not ‘fire rated’, increasing the risk of fire spreading between floors or into the loft space.

AndyC says:
22 March 2017

I have come to this forum following the fitting of “bulbless” LED lights in two rooms today by my usual electrician, who had recommended and supplied the units. These LEDs have multiple small diodes in each fitting. Each fitting also includes a step-down transformer as the LEDs operate on 12 volts. With low operating costs, no bulbs to replace, a bright light and a long-life guarantee, these lights surely represent the future. But, with my bulbs at least, not if you still use FM radio. There was significant interference throughout the house, and the signal was completely obliterated in the worst affected areas. Both DAB and TV remained unaffected. An expensive mistake for my electrician, unless he can get a refund from the wholesaler.
Strangely, I have multiple LED bulbs from several different manufacturers throughout my house, including downlighters, and also LED strips under kitchen cupboards which also use a step-down transformer, and have never before experienced any interference on FM, DAB or TV.
This long-identified problem does not seem to be going away.

AndyC-If you are experiencing radiation in the HF range from the new fittings then the “so called ” transformer supplies are not linear / analogue transformers but SMPS . The old type of transformer is a dual induction winding mostly on an iron core (but not always ), with a Primary/Secondary winding isolated from each other using a full wave solid state rectifier + smoothing capacitors . This will not create HF radiation but a SMPS operating at a high switching frequency will . REAL transformers can be recognised by their bulky layout and give off some heat -SMPS are very small and dont usually radiate heat unless inside a lamp . What I am saying is that 12 Volts is a standard output voltage for low voltage use and does not generate any radiation ASK your electrician if the transformers are actually SMPS ?

AndyC – I suggest you explain the problem to your electrician and demonstrate that other LED lighting in your home does not cause interference. Many of the problems reported in this and other Conversations relate to 12V LEDs rather than mains voltage ones. Hopefully he will be happy to replace your lamps.

If you bought the lamps yourself and had them fitted, then you will have to go back to the retailer and ask for a refund or replacement.

Interesting Wavechange , while LED,s could be accused of giving off a little UV light radiation they, in themselves do not naturally radiate at HF/RF levels , so what you must mean if its supplied from from an analogue (transformer fed supply ) is that instead of a simple power output supply of solid -state diodes/ zenner diodes /etc there must be a microchip controller operating in SM (switched mode ) now that would give off some radiation . I know you need facts from reputable sources so click on – LED information and technical Data -Indiana University : http://users.ipfw.edu/broberg/documents/LED_Data.pdf

Thanks Duncan. I’ll look at that later. The LED downlighters in my bathrooms each have a separate SMPS in the loft and I don’t have any significant problem with radio interference. Had there been a problem I would have installed a transformer or mains voltage LEDs.

Thank you wavechange and Duncan. As a non-techie, I have left the problem to my electrician who has recommended moving back to a previous era and installing fittings with CFLs instead. Three downsides: more expensive to run, expensive bulbs to be replaced at intervals, and slightly poorer light. Unfortunately, I am out of my depth with your technical discussion!

I hesitate to say this but I spent some time checking out radiation from CFL,s in the UV range and it isnt that good very long term for the eyes . You would think this all came from minority websites but I found a few US tech company and + US product safety websites actually producing long winded science data along with spectrum analyser screenshots showing the amounts compared to other lighting products. I am still curious AndyC47, did he admit the “transformer ” power supplies were -SMPS ?

CFL lamps are prone to phosphor cracking, which can cause UV leakage.

Didnt know that Ian –thanks.

I doubt that the area in the phosphor cracks would lead to any significant UV leakage from the low pressure mercury discharge – unless you have evidence to the contrary. https://ehp.niehs.nih.gov/120-a387/

All the research I’ve seen suggests a very low level and almost certainly harmless from a reasonable distance. But there’s still not a great deal of data, sadly.

As usual you have to go to America to get any relevant info. It gets no better than the US Food+Drug Administration and they give info from the United Kingdom Heath Protection Agency-quote -a recent study has found that there are measurable levels of UV from single envelope CFL,s when used at distances closer than 1 foot and dont use them at that distance for more than 1 hour/day , they recommend keeping more than 1 foot from them . Now why is it so hard to get this info on UK websites ??

“As usual you have to go to America to get any relevant info.”. Not so. Try the Lighting Industry Association (in the UK!): search on CFL UV hazard:

Malcolm have a read of the : http://ehso.com/cfl_light_bulb_uv_skin_cancer_risk.htm it quotes from Stony Brook University NY and comments on cracks etc.

This says nothing as far as I can see that other links – see above – don’t say. Few people would have skin constantly 1 foot away from a bare CFL I suspect. I have given another link above to hazards from UV.

There is nothing in our homes that isn’t hazardous if not used sensibly.

This Conversation is about radio interference from LED lamps and, at this point, about problems with integrated LED fittings not having separate bulbs. We have some integrated ceiling-mounted LED light fittings that have not given any problems with nearby radios in either FM or DAB mode.

What about under kitchen cabinet lighting?

Good point Alfa your eyes will be inches away from the light and you would be looking in there several times a day.

Are you thinking of radio interference [LED’s] or UV leakage [CFL’s] Alfa?

LED under-cabinet tubes have not caused radio interference in our house. I cannot comment on the flexible LED light strips that have become popular for auxiliary lighting above and below the upper cabinets and at plinth level as we have no experience of them.

CFL types are just like mini fluorescent tubes which we had in our previous house. As Ian and Malcolm have already said, UV leakage is likely to be minimal and harmless; they have been in use for decades and I am not aware of any specific warnings.

It is not commonsensible to look directly at any lamp. Under-cabinet tubes can be fitted so that the light source is shielded either by the placement of the fitting with the tube facing the rear or by the fixing of a small strip of wood or plastic as a baffle; some also come with diffusers. One would not normally see the strip light unless one’s head was under the cabinet looking up.

I’ve installed some flexible LED strip lighting beneath the bannisters and the light from them illuminates not only the stairs but the hall at the bottom. But no interference from them, and they remain on throughout the day.

Due to others incompetence, we will have a mixture of LED and CFL mini strip lights under kitchen cabinets that should be behind some sort of shielding.

That might at least give you better options for radio positioning, Alfa.

If I were you I would swap the CFL’s for LED’s and hope you can still get the Light Programme.

If we could get a full refund, we would swap them. Benchmarx are happy to sell you anything at full retail cost, but it would be easier to get blood out of a stone than get even a partial refund out of them.

Sara Steeples says:
13 April 2017

We bought John Lewis Modena LED Backlight Spotlights, Silver, 4 Light . When watching BT sport I switched the lights on and the picture became really pixelated and we couldn’t watch it. When I switched them off the picture came back on.

Rob Harrison says:
17 April 2017



Just go to youtube and search LED RFI and see the extent of the problem. Huge!!

The legislation is there to stop this but government, and it’s relavent departments(OFCOM in the UK) is ignoring it in favour of consumerism. As that’s what drives our economies now.

This problem is completely solvable techically, given enforcement and willingness.

Don’t hold your breath.


Howard says:
26 June 2017

I recently added some cheap LED floodlights in the garage but immediately noticed they are knocking out the Internet on my TP Link power line adapters, as well as wiping out my radio reception. The problem is exacerbated on the house which uses the power line to transmit cctv. The second the LED floodlights comes on the camera reception goes off, and the would be burglars have a free-for-all!

Does alone know if there is a filter available that I can put on the lighting circuit to stop this RFI coming back and affecting the 13amp circuit?

Howard , if the floodlights are plugged into a 13 amp socket then Maplin -UK sell a extension strip , if you have wired them directly into the ring main then you would need an industrial version which would be dearer -Bulgin for example . I had a look at Maplins filter its a extension strip for HD TV etc and selling at a reduced price but I am loath to recommend it to you as those LED spotlights have pretty strong “dirty mains ” injection , there are professional types available ( much dearer ) .As its only £18 its worth a try but I am not guaranteeing it .

Howard, you’re probably better off buying better-quality LED floodlights.

The trouble is that we don’t know which lights will perform better. Seeing these posts reminded me that I have a cheap LED floodlight bought in Lidl two or three years ago to use as a work light. I’ve just checked and there is no interference problem. I think the best advice is to return lamps for replacement if they do cause interference.

The video provided by Rob Harrison is interesting.

Just replacing the lights from the same seller may give you the same problem. Whilst price does not guarantee performance I’d suggest buying cheap is more likely to give you poor circuitry, which is what will produce (or not prevent) the interference. I know we all like a bargain, and usually they are found online, but if you want a floodlight you may be better dealing with a reputable accessible retailer and then if you do have a problem you’ll have more chance of getting it resolved. A device such as a floodlight will need to comply with regulations for interference so, if it correctly installed, a non-compliant device will be for the retailer to sort out.

Hopefully the retailer would provide an alternative brand or a refund, otherwise they are likely to have to deal with the same problem again.

The Lidl lamp is branded ‘Livarno’ and made in Germany. From memory it was less than half the price of similar lamps sold in a couple of DIY stores at the time. I had not intended to use it frequently but it often gets left on for hours in my workshop. I am not a great enthusiast for Lidl products, but here is one that I can recommend. Lidl hardware is often on sale for a limited period, so the solution would be a refund.

The problem in buying an appliance that may not work properly is that if you have to pay someone to install it, the cost is likely to be more than the floodlight. Repeating the exercise is good money after bad.

If you can install it yourself then you can risk wasting your time. I probably would, but when you buy cheap you must expect something that may have limited life as well as poor performance. How long will the LEDs and the PIR (if fitted) last, for example.

By the way, don’t aim the floodlight outside your boundary and annoy your neighbours, as some do. You need to tip it down so the beam falls inside your property.

Good point at the end, Malcolm. I get fed up with seeing floodlights not adjusted correctly to cast the beam inside the grounds. There’s one I pass on a sports club building that is pointing straight out at the road; if an intruder was trying to enter the building at night they would have perfect cover because the glare from the bright floodlight makes it impossible for anybody to see what’s going on. In my opinion a floodlight should be mounted high up and the face should be flat or as near flat as possible to illuminate the area without huge shadows.

In my case I bought the lamp to use as a portable work light for DIY, though I put it in the workshop when I moved home. It has performed well. I might buy another one to use as a work light, though purpose-designed LED work lights are now readily available.

If I paid someone to install floodlights, they would normally supply and fit the products, possibly with my input on choice of lamps. In that case, my contract would be with them and they would be responsible for sorting out problems such as radio interference and premature failure.

“… when you buy cheap you must expect something that may have limited life as well as poor performance.” It depends what you mean by cheap. I would steer clear of the pound shops but as an experiment I bought some Status LED lamps, which were considerably cheaper than the better known brands. I deliberately put them in locations where they would be well used. They are still working fine and not causing radio interference.

Sally Hawthorne says:
18 August 2017

Just changed over to LED bulbs brand LAP GU10. Really struggled to get the retainer clips for 9 bulbs to hold them in. Profile is very slightly different around rim where it is out of sight in the recess. My patience has been strained to say the least! Having finally got the last clip in, in a fashion, I now find the reception on my DAB radio affected when they are switched on.
Purchased from Screwfix.

I suggest you take them back to the Screwfix store, or contact the company if you bought them online. It’s best to try a single lamp and see if that causes a problem before fitting a set. It’ not much fun working above your head.

Please let us know how you get on, Sally.

Malcolm W says:
7 September 2017

I noticed that when I use my Radio (walky talky) at work the LED lights flicker……not sure what the frequency is on the radio is.

Malcolm W If it is a genuine “walkie-talkie ” then it could be an indication of the transmission strength (power )-ie- transmission or reception power .Thats just one reason for it flickering there are others for different pieces of equipment.

I have been looking at a hand-held VHF radio for a friend and have sorted out a problem with the charger. When transmitting, it has no effect on any of the LED lamps in my home, even very close to them. The operating frequency will be different from a walkie-talkie.

Wavechange UK legal public walkie-talkie frequency range – 446Mhz (approx ) public service have different frequencies so well above FM radio and double the British digital radio frequencies so harmonics cant interfere directly on them from walkie-talkie,s.