/ 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.

Old_Codger says:
1 November 2013

The debate above is all very interesting, but not useful to those us who want to use LED lights AND their DAB radio at the same time and in the same room…

Does anyone know of MR16 and GU10 LEDS that do not cause interference?

My set-up – for those that insist on answering “it all depends”..:
12 MR16 lamps of unknown wattage, vintage or label in the kitchen ceiling. Unknown transformers, unknown dimmer switch – DAB radio in bedroom above and second radio in Kitchen/diner. Interference happens with just a single LEDhut MR16 over a range of 15ft.

*Type MR16SMDN-3X1 and I know LEDHut got done recently but even this months Which? says they claim they don’t ship that type anymore…

Interesting that this congo should resurface again: yesterday I went to my local electrical retailers for a few oddments and noticed that he had his managed alarm system engineer in, tinkering with the controls.

As I always have a chat with the proprietor anyway we got talking and after a while the alarm engineer came and asked to speak to Phil. The conversation as along the lines of “when did you first get these false alarms?” … “about 3 weeks ago, about midnight” …. “does it happen every day?” … “yes” … “about the same time?” …. “yes” …… “and always the same zone?” …. “yes” ….. “the shop windows?” ……. “yes”….

The engineer went away for a while and was poking around in the shop window and then came back to ask “it looks like you’ve recently had the lights changed over the window?” …. yes, that was about 3 or 4 weeks ago”…..”what sort did you have before?” …. “Fluorescent tubes”……

engineer went away again and then came back “I think I’ve solved it, do your window lights automatically switch off late at night?” … “Yes, about 11:30ish” …. “I think it’s these new spotlights you’ve had in, the driver unit is near to the alarm cables and I think it’s causing interference when it switches on and off” … “why doesn’t it set the alarm off when they switch on then?” ….”what time do they come on?” …. “about 9:00 in the morning” … “and are you usually here before they come on?” … “oh yes, about half an hour before” … “so the alarm is not set when the lights come on ?” ….. “ah, I see what you are saying!”

Engineer and shopkeeper then locked shop door briefly, switched off window lights, set alarm and switched on window lights ….. sirens blaring, lights flashing ……

So it seems that the LED driver unit for the little low voltage LED track of lights over the window causes EMF (or EMI) triggering burglar alarms too ……….

Old_Codger says:
1 November 2013

In my case taking out one single halogen MR16 bulb and replacing it with one single LED MR16 bulb causes both my DAB radios to stop working. Even though it is 15′ away.

This isn’t acceptable as I want the lights on and to be able to listen to the radio at the same time! (I am picky like that…)

Elsewhere in the house I need GU10 bulbs.

Hence my question – does anyone know of replacements that definitively do not cause interference?

Gary M0PLT says:
1 November 2013

At the moment, Old_Codger, all MR16 lamps which use LEDs should be considered non-EMC-compliant. Most of them appear to use buck-driven current/voltage limiter circuits, and it is these which create the vast amounts of radio frequency interference. Resistor limited lamps are few and far between – especially if the lamp is using an over-driven multi-chip diode. These typically require 80 (or more) milliamps, and dumping that amount of current through a limiting resistor makes for an extremely hot and inefficient lamp; although it would be RF silent! You will be better off sticking with halogen lamps. They are cheap, typically offer a 5000 hour life, and they will not cause interference!

As for GU10s. I have tested a Philips GU10 LED and found it to be OK; and two of their SES LED lamps are also fine. That is not to say other manufacturer’s products are safe from generating RFI (Philips MR16 lamps are not compliant), and it is no guarantee the Philips lamps will not suffer a future failure which causes RFI, but leaves the lamp working.

Old_Codger says:
1 November 2013

I am a little confused. I didn’t realise there was any electronics in an MR16 Bulb? What are buck driven limiter circuits?

That said there probably should be some if there’s to be RFI/EMI suppression.

Has anyone experience of these? They claim to be EMI free and comments on the AVForum linked above suggests they are good.


Gary M0PLT says:
3 November 2013

Not all MR16 LED lamps feature regulators. Those which use a cluster of standard LEDs are usually configured to run at 12 volts with no limiting resistors needed. i.e. most white LEDs work around 3.4 to 3.6V. Stack 3 or 4 in series and they will happily run off 12V with little/no regulation. Those which feature a multi-chip LED (four or six diodes in one package) need to be fed with a regulated 3.5 volts at no more than 20 milliamps per chip. This is typically where the buck-drivers come in.

A buck-driver is a type of switching power supply – akin to a switched-mode power-supply. They typically feature a controller chip, a transistor, an inductor, a rectifying diode, the LED (or LEDs), a clock capacitor and a tank capacitor. They work by switching current into the inductor’s coil to induce a magnetic field in the ferrite material. When the current is switched off, the magnetic field collapses and induces a current in the coil – known as ‘back e.m.f.’ This current is rectified through the diode and the LED with some filtering/smoothing provided by the tank capacitor. All sound in principle. However, high frequencies need to be used in order to create a saturated magnetic field in the ferrite material, and high radio frequencies tend to leak if not properly shielded. At radio frequencies, the rectifying diode (and the LED) acts as a mixer, creating a mush of RF harmonics. The mush then finds two nice straight bits of wire to act as an aerial to ‘transmit’ on. It is this mush that wipes out radios.

Many in the radio field feel there is a better way of regulating current in LEDs that does not require the building of a high-powered transmitter. Simply switching a transistor (with the LED as its load) with a suitable waveform will regulate the current and avoid all that nasty RFI; plus is has a lower component count, and would thus be cheaper to build!

Thanks for the interesting comments, Gary.

I know very little about the circuit design of led lamps but it is obvious that achieving high light output and minimising heat generation are high priorities when using LEDs in compact lamps designed as replacement for incandescent lamps. I can certainly relate to interference generated due to collapse of magnetic field in inductors but I wonder how efficient transistor switching would be in practice.

Mike says:
1 November 2013

At the risk of repeating myself, I have found that none of the LED bulbs that I have bought from LIDL and Costco interfere with any of my DAB radios. However both of those retailers sell items from different manufacturers, so there’s no certainty in the future. I don’t have any MR16 LEDs, and because of the information on this forum I won’t be buying any.

For what it’s worth, the GU10 bulbs that work fine for me are:
Feit Electric BRGU10/DM/LED/UK 6.5W 220-240V 50Hz 40mA 30000K 350 lumen 38 degree 260-13-30 CE-marked (6 LEDs, Costco)
Feit Electric BPGU10/HP/LED/UK 4W 220-240V 50Hz 58mA 260-12-12 CE-marked (3 LEDs, Costco)
Luminus B-PUK2013 LED GU10 30000K 38 degree 3.5W 230V 50Hz 30mA L11-57235, CE marked (3 LEDs, Costco)
The Lidl GU10s are branded Livarno, have about 15 LED clusters and presumably capacitive ballasts. There’s no EMI at all.

Most of the Lidl LED bulbs that I have are E27, and I also have a couple of Philips E27s, 5.5W 2700K 350lm 44mA 9290002158A. None of the E27s interfere with my DAB radios either.

I should probably point out that I don’t have a very marginal DAB signal, although it’s not super strong (80-100% on a Pure Evoke, internal aerial). The three and five LED bulbs presumably do have switch mode supplies, and do reduce the signal quality indicated by my radios if the aerial is held right next to the bulb (although they don’t cut out or burble), but at 500mm there is no detectable effect at all.

Hope that helps.

Old_Codger says:
2 November 2013

Mike, many thanks. The feit 6.5 watt GU10 look interesting, particularly as at 380 lumens they are also very bright – that’s approaching the light levels from halogens!

I wonder how much of the issue with DAB radios is down to poor design / poor quality of digital radios as well as the interference from the lamps?

Any audiophile will tell you that DAB radio is a very poor reception compared to analogue to start with, then we have the issue of marginal signal areas (as mentioned by Mike) and on top of that I notice that the majority of tablet or ‘portable’ DAB radios seem to have their own, often dubious quality, switch mode power supplies rather than transformer supplies. I can’t help but wonder whether the unavoidable lower quality reception that is the very nature of DAB, plus a possible (if not probably) issue over signal strength, PLUS the likelihood of the radio having a poor quality PSU AND THEN the issue of energy saving lamps being prone to cause RFI / EMI all add up to a recipe for radio failure?

I have to say that, although I have had issues with energy saving lamps affecting ANALOGUE TV and playing havoc with Infra-Red remote controllers, I’ve never observed any interference with my analogue radio reception from energy saving lamps, though the fact I have a rooftop VHF / FM aerial and the aerial cables come down the outside of the house and then under the floor to the Hi-Fi – i.e. not at all near to any light fittings of any kind – may at least partly account for this.

Old Coger and John – have you got an option of trying an external aerial at all to see if this helps? I know you should not have to invest in one just to make your radios usable again after buying energy saving lamps, but if you have access to such an aerial it may be a useful experiment?

As an afterthought – I bought two sets of outside Xmas lights last week – both of them LED lights with tiny plug in power supply plugs. I’ve actually taken them to Trading Standards because the box and instructions clearly state that the “Isolating transformer” must be kept indoors and dry, but the PSU plugs are not isolating (or any other type of) transformers – they are exceedingly low quality switch-mode PSU’s in cases which are easy to pop open exposing live parts and with plug parts which contravene the requirements of BS 1363 in terms of finger guards.

Trading standards took photo’s of the stuff but left the goods with me – they didn’t seem to think there was a problem – but as an experiment, tomorrow I will plug in one set of these lights and try waving them around near to my Hi-Fi and TV and see what (if anything ) happens. If anything exciting occurs I’ll post it on here for you.

Old_Codger says:
2 November 2013

Thanks. Do let us know if they cause radio or tv interference. I need to replace my tree lights this year and was thinking of LEDs, if only to cut down on the annual game of find the loose bulb….

If they are going to interfere with the the tele, then I am afraid that I will continue to warm the planet and drown polar bears by using incandescents….

Radio and TV interference problems are best tackled at source, but a roof or loft aerial will improve reception, particularly in weak signal areas, as Dave has suggested. Few would think of operating a TV with an internal aerial, but both DAB and FM radios are usually expected to work with a small telescopic aerial. Quite apart from interference from LED lighting, there is a lot to be said for having proper aerials. I have a DAB rooftop aerial and an FM loft aerial.

I think switched-mode power supplies vs transformers is a bit of a red herring. Few portable items now use transformers, which are heavier and waste more power. If a radio with a switched-mode power supply powering it is working fine, then it is a good indication that these power supplies can be designed not to interfere with radios!

Anyone with a battery/mains portable DAB radio can do some detective work. If the problem is worse when plugged in, that suggests mains-borne interference. On battery power, the radio can be used to explore the source of the interference and how much of the house is affected.

From what I have read on this and other websites, the main problem with LED lighting is the switched-mode power supplies used to supply 12 volt lamps, such as the MR16 variety. Laptop computers, cordless phones, mobile phone chargers, routers and many other home electrical items use switched-mode power supplies and we rarely hear of interference problems. I suspect that all the manufacturers of power supplies for LED lighting need to do is to redesign their products, possibly by changing the frequency that their power supplies operate to one that does not create a problem for radio users.

For the time being, I will continue to use CFLs, which are cheap, economical to use, and I find them very reliable.

Old_Codger says:
3 November 2013

I am tackling this at source. The source is the LEDhut MR16 bulbs…

The problem with this subject is this problem is technically complex and this provides everyone with the opportunity to say to blame another link in the chain.

I take a very simple view, I want to be able to put an LED MR16 bulb into my existing circuits for Halogen MR16 bulbs and for them to work without stopping other things (eg my DAB radio) from working.

It seems it is possible, but it is not easy to find out which bulbs suit – because none of the seller’s websites provide information that radio Interference even exists. I only found out when I read this months Which? Magazine.

Well, the fact that Which? have even admitted it themselves in their mag is a step forward compared to previous Which? reports and tests which have been myrmidon-esque in their towing of the government (UK and EU) lines. Some credit at least to Which? for that!

Ikea Candle, SES screw LED lamp destroys DAB and FM even a good 3m away from the lamp.

Old_Codger says:
3 November 2013

Thanks – another one to avoid then.

I have discovered by borrowing a bulb that the KSR lamps work alongside my radio. to be exact or rather a GU10 KSRLP 852 GU 10 bulb is OK. They are not dimmable and they are pricy at £15-25 on the web.

And the fact they are so expensive is, I suspect, linked to the root cause of the problem: as Wavechange has said countless times with regard to most different types of low(er)-energy lamps, we are trying to cram electronics into minuscule packages and sell them at – quite literally – throw-away prices in order to make retro-fit lamps which (supposedly) save some energy. If the electronics were moved into the fittings – thus having more space and better ventilation – they would be more reliable and longer-lived. People would also be more willing to pay a little more for them, which would mean that better quality components and better designed circuits would be feasible – likely leading to the removal of issues such as the interference one that you are battling with, and overheating / short life / fire hazard issues which have come up repeatedly in the past (usually regarding cfos).

Old_Codger says:
3 November 2013

These things get fixed one step at a time, and in a way that allows everyone to adapt at their own pace.

I.e you get the idea established.
You implement your current best idea.
You learn the problems
You invent fixes
You implement fixes
You learn the problems….

While what you say may be right it ain’t going to happen.

I want to do this but it will cost me say a tenner per bulb. I have 25 bulbs (previous owner seemed to like MR16 fittings) If I need to change the 25 transformers as well it will cost me , say, an additional £15 per fitting. £625 buys a lot of electricity.

There will never be an economic reason for me to do this, it is pretty much dead economically at £250 and much as I want to do my bit, I am not spending this much to do it.

The cost and low light output of current LED lamps intended for domestic use is enough to put me off. We seem to be discussing LED lamps that produce less light than an old fashioned 40W incandescent bulb, which has an output of around 450 lumens. I predict that if enough LEDs are crammed into a lamp of equivalent size and light output (around 1600 lumens) of a 100W incandescent lamp it will not be reliable unless fan-cooled. On the other hand, there is huge potential to use LED lighting without cramming all the LED chips into a small space. At the university where I used to work, superb rectangular LED light panels have been fitted. They are very bright and ideal for laboratories, but the cost is silly. I expect they will be reliable because the LEDs and control electronics don’t have to be crammed into a small amour of space.

I expect that in a few years we will have inexpensive LED lamps and that downlighters will be largely replaced by less localised sources of lighting.

Dave has made an important point about fire hazard. It is amazing how many people are prepared to buy LED lamps and other mains electrical products that are unbranded and often sold by little-known online traders. If I get round to buying LED lamps I will be looking at well known brands such as Philips, GE and Osram, with a reputation to protect.

Gerry says:
3 November 2013

Inexpensive LED bulbs are here already, at least in the USA.


They look EXACTLY the same as a traditional frosted incandescent bulb: same colour light, omni-directional, and at 800 lumens they are every bit as bright as a 60w.

Unfortunately they don’t seem to do a 240V version !

Dimmable too, though perhaps not essential for the equivalent of a 60 W incandescent bulb.

Of course, what we all want to know is whether we can carry on listening to our DAB and FM radios. 🙂

And at £8.13 (based on today’s exchange rate) far cheaper than many of the rubbish ones we can get in the UK and certainly well in line with the majority of our prices.

Possibly another example of the UK always ending up with the world’s rubbish?

We tend to lag behind the US, Dave. Sometimes that is an advantage. I expect that the prices will fall dramatically.

The lamps mentioned by Gerry are made by Cree, a highly respected name in LED lighting. It is interesting to look at the low customers’ ratings. There are numerous comments about problems, especially buzzing, when the Cree lamps are used with dimmers. I have not spotted any comments about radio interference. Perhaps the US has abandoned FM and DAB in favour of Internet radio or these lamps might be worth buying from overseas for anyone keen to be an early adopter of LED lighting.

Bob Purbrick says:
5 November 2013

I wonder what advice should be offered to anyone contemplating purchase of LED lighting. Here are some thoughts:

LED lamps may cause interference with DAB and FM radio, especially when used in the same room.

Low voltage LED lamps are a more common cause of interference than mains voltage lamps.

It may be useful to borrow or buy a single lamp for test purposes, since interference can vary with different brands.

It is worth checking that a supplier is aware of the problem and is happy to give a full refund in the event of a problem.

I hope Which? will issue its own advice, because a lot of money is now being spent on LED lighting.

LED lamps are good where you want a linear light, as in strips under cupboards for example, small light sources – as in spotlights, and where you want instant full light output. Otherwise you could ask why not use compact fluorescent lamps for general lighting when they are normally cheaper than LEDs, better colour and probably as efficient. In all cases buying a mainstream brand is a better bet than risking an unknown – the electronics are likely to be properly designed and of better quality.

I would be very concerned that cheap products from unknown companies could be a fire hazard. There’s some very dodgy mains electrical products on sale and though I am not aware of problems with LED lighting, I do not see the point in taking the risk.

AND what about this then:

“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. ”

How much of this was/is foreseeable when technologies for the mass-market are launched. A multi-billion euro market with pressure on people to adopt low-energy products one would have hoped that standards would be in place. Or is it just the US where LED’s are operating near maximum temperature.

LEDs have often been operated at near to their maximum junction temperature, so the highest current can be used to get maximum light output, albeit at sub-optimal efficacy. This temperature is around 135C. However, “light bulbs” that are self contained will also contain the electronics to supply the required current and these will have a significantly lower limiting temperature – 75 to 85C seems in the right area – which is what will limit the life of the package. As with CFLs it is much better to have separate electronics that are not subjected to heat from the light.

LED lighting is likely to suffer the same reliability problem as CFLs until we move away from direct replacements for incandescent bulbs. Only when we keep the control electronics cool can we expect a decent operating life. In addition, we need to keep the LEDs themselves from overheating.

We need to ‘think outside the bulb’ and design light fixtures that are significantly larger than what we are accustomed to. The problem of dissipating heat is why we don’t see LED lamps that have the light output of 100W incandescent bulbs on the supermarket shelves.

Tony99 says:
16 November 2013

I’ve just installed twenty two MR11 (12V 2.4W ) LED bulbs with a 60W LED Transformer and this has caused sever interference on FM radio. I have tried 3 different radios, all are severely affected. My crude tests indicate the interference is probably coming fro the lights rather than the transformer, but it is very difficult to tell. I can sometimes get an FM signal in the proximity of the lights, but it becomes incredibly directional.

I’d be happy to supply details of makes and suppliers if it would help.

Please do supply the information Tony. It all helps.

I have been given a second-hand Steepletone radio which must be one of the shoddiest bits of kit and I find both my GU10′ lights and my induction hob create interference on LW when the radio is in the bedroom above the kitchen. The induction hob effect is pretty obliterating and quite impressive as it pulses. The interference also occurs downstairs in the kitchen but in both cases it is possible to find parts of the radio spectrum where it works fine – if not on the channel you wanted! : )

I have also an elderly Philips portable in the kitchen which is permanently tuned to Radio 4 which is not affected in any way. This quality of the radio electronics obviously is a factor. I had a look at the Which? Best Buys to see if with DAB radios suscpetiblity to electronic inteference figured but cannot see it mentioned.

Bottom line though is , judging from all the posting, that interference could be a major pain for the average consumer and Which? ought to update its advice on LED lights pending some serious attempts to stamp out shoddy products. It should also be mentioned that the Which? table of best LED bulbs shows the year, as in up to 35 , that these LED lights could last. As we know from the Conversation thread contributors these figures are highly unlikely in any current fixing where the temperature is efficiently not dissipated.

Old_codger says:
16 November 2013

I have found two MR16 bulbs that do not cause my DAB radio to stop working. These were a Philips 5.5w non dimmable warm white which I got from John Lewis.

Philips 5.5W MR16 Energy Saving LED 12V Spotlight, Clear

I also tried a dimmable bulb, again from Philips a MASTER LEDspot

Philips 7W Master Dimmable MR16 LED – Warm White (36°) from these folks

They are not cheap at £15 and £18.70 respectively but they do work and don’t interfere with the radio.

I would emphatically not use LEDHut bulbs. The ones I bought caused very high levels of radio interference when I plugged them into my existing circuits. (The same circuits those Philips are now in!). Their no quibble returns policy is a bit of joke as well as it took tens of emails and three phone calls to get them to give me my money back. They claimed that the bulbs were not faulty – it was my circuits.

Old_codger says:
16 November 2013

I would add that in future I am going to convert the recessed light fittings from MR16 to GU10. It will cost me about £10 a fitting andi will have a much wider choice if bulbs I can use. No hassle with transformers and so.

I have a pair of homebase GU10 cheapies 2 for a tenner, which give off a good whiteish light (3000k) and no interference!!


Thanks cold codger. This has been one of the more useful conversation threads and hopefully will save readers money and frustration. I thought I would see where Which? website is on LED’s and problems:

“Why should I buy LED light bulbs?

There are three types of energy-saving light bulb: compact fluorescent lamps (CFLs – the most common type of light bulb), halogens and LEDs.

LEDs are the most expensive, but do have benefits over the other types:

LEDs use 90% less energy than incandescents (CFLs use 60%-80% less than incandescents, and halogens use 20-30% less).
LEDs are claimed to last for 25-30 years, dependent on use.
LEDs give out their light quickly at start-up, so you don’t have to put up with a few moments of dim light when you flick the light switch.
LED lights don’t contain mercury (CFLs do, although it’s only a small amount)
Our tests have found that LED lights, like halogens, work fine in low temperatures, whereas CFLs don’t

At Which? we’ve reviewed and rated more than twenty LED light bulbs in brightnesses up to the equivalent of a 60W traditional incandescent bulb. Go to our LED bulbs rated page to discover which light bulbs we recommend as Best Buys, or see all our Best Buy light bulb reviews if you’re still considering compact fluorescent lamps (CFLs) or halogen lights. ”

Unfortunately this March 2013 conversation seems to be the only place where interference and LED bulbs appears. The closets to a warning is after the why buy:

What should I look out for with LED light bulbs?

Until recently, LED light bulbs have generally only been available in lower wattages and lumen levels than other types of light bulb. So although they are quick to reach their full brightness and suffer no decrease in performance over time, they are often only available in dimmer varieties than CFL and halogen bulbs. This is improving all the time, however, with brighter LEDs becoming increasingly available.

“Some people don’t like the quality of light given out by LED light bulbs, as they tend to produce a cooler bluish light, so take this into consideration when choosing the best ones for your home.”

You need to choose both LED and CFL bulbs carefully from reputable suppliers. LED light output is reduced at high operating temperatures, as is life. A realistic life for quality LED bulbs is around 15 years at 4 hours a day. Poor quality LEDs may suffer from failure of the electronics before the LEDs. Cheap ones will fall in light output from using poorer quality phosphors. Higher outputs come from the colder white colours (bluish) and can be quite unpleasant. Good colours fall between warm white (2700K0 and White (3500).
LEDs give between 60 and 80 lumens per watt – careful of inflated claims – they may be in temperatures you will not achieve.
CFLs give around 60 lumens per watt but are available in larger light outputs. Good ones will last around 7 years.
Is the 25% watts saving for an LED (around 60p – £1 a year at normal use) worth the extra cost of the LED? It’s worth checking.

Old_Codger says:
17 November 2013

Old Codger / Cold Codger – Nice slip, but I am not dead yet… 🙂

My hope is that there is now enough here for Which? to look into this seriously and update their best buy data to show RFI…

John Dalton says:
20 November 2013

At last a BEST BUY!!! I have been looking for over a year for MR16 replacements which don’t interfere with my FM reception. At last I have FOUND SOME and they were at a very good price too. The bad news is they were in Lidl this week and I bought their whole stock after trying a pair out at home. At 2 for £9 they are the least expensive 5W MR16 (12v) replacements I’ve seen and should pay for themselves in electricity savings in less than 6 months (at 5 hours use per day) and if the life claims are right at 20000 hours and 30000 on/off cycles they should last at least ten years.

They are branded LIVARNO LUX, and described as GU 5.3 but they are the same form factor & fit as MR16. Proper geometry CE mark on the packaging, Chinese compressed version on the bulb itself, but also TUV. Conservatively rated at 25W tungsten equivalent, 230 lumens warm white (only a 46 lumen per watt claim, whereas some other brands boast as much as 60!) they seem a bit brighter than the 25W tungsten halogens I’m replacing, and a similar light colour. I am over the moon with joy.

I don’t have a DAB radio so can’t vouch for suitability around those. But no problem with FM whether driven by HF transformers or plain mains magnetic transformers. They say not dimmable, but that’s fine by me – I want them on full beam.

Spec from the shaft of the bulb itself (now there’s something different from the rest too!) IAN91149 Model no Z31540A 5W 3000K 620mA 12V 50Hz GU5.3 230lm 30 (degrees beam)

If you want some too get down to Lidl quickly – they don’t always stock them, I think it was from last Tuesday only.

John Dalton says:
20 November 2013

Apologies for my maths; on electricity saving it’s more like a year to break even. 20W saved for 5 hours/day makes 0.1 kWh saved per day so 1.6p. 300 days of savings more than covers the £4.50 cost. If they last 10 years as promised I’ll save about £50 per bulb over their lifetime in energy and bulb replacement.

Good Luck!
I would be very interested to read of you r progress with them and if the convo still exists in one year and beyond it would be great if you could give us some updates.
I would love to use LED lamps, but their cost at present, plus the awful experience I’ve had with CFL’s (totally different thing I know) means I’m not willing to risk buying LED ones just yet. It’s still going to take me another 4 or 5 years of using old fashioned tungstens everywhere to make up for the cost of the CFL’s I’ve had which have gone bang or otherwise failed after anything between about 3 hours and 1 year, none of which have ever been used for more than about 2 hours per day and most of which have not been switched on on at all more than about 3 or 4 hours per week.
If CFL’s and LED lamps lasted even half the indicated life on the packets we woudl also save a huge amount of money, but as yet I’m in deficit through having tried.
PLease do keep us updated: you are using the lamps in “real” situations; Which? tests are all based on using the lamps in artificial situations which it would be almost impossible to mirror in real life, so your results will be extremely valuable to us all.

Thanks for the heads up JD. I am a great fan of the two German chains because they do really believe in quality control unlike many chains who are apparently happy to import tat.

David Farnell says:
21 November 2013

I have waited about 12 months for a solution, then I read the ‘Old_codger’ solution to fit Philips 5.5w MR16 LEDs which do not interfere with DAB.
Today (21-Nov-2013), I have swapped out my ‘noisy’ LEDs and replaced them with Philips 4.0w bought from eBay and at long last, the intererference has vanished!!

The bulbs are labelled as Philips 4W GU5.3 MR16 3000K 12V AC 36D 520mA

I think the important part of that is: Philips.

I hope this feedback is helpful.

Andy Thomas says:
15 December 2013

I have had similar experiences with DAB radio interference. I’ve tracked this down to the IKEA 12v MR16 lamps in light fitting in the kitchen. I also have GU10 LED down lighters in other rooms which give no problems at all with DAB radio. I haven’t tried changing out the low voltage transformer in the affected fitting for an LED driver, but picking up on comments in earlier post I’m not sure that would change anything, but as these are relatively cheap it might be worth a try.

Could the interference problem be related to the transformers or “drivers” being used?

I had not paid any attention to this as I don’t have any LED lamps in use in my home at present, but the City Council is currently replacing all the street lights in Sheffield with LED ones and I’ve done a shed load of research in the past week into the new fittings that are going up, and I see that the manufacturers (Philips in the case of our street lights) mention the importance of using solid-state LEd “drivers” and not transformers if retro-fitting LED units to existing street lamps.

It now crosses my mind that maybe fitting 12V LED GU10 spots in to fittings powered by a Halogen lamp transformer could be a problem whilst using a LED ‘driver’ may not be. Possibly the ‘driver’ circuits have suppression built in to them?

old_codger says:
16 December 2013

My take on this it is an INTERACTION problem between some types of LED MR16 bulbs and the transformers. The transformers do not cause a problem with halogen bulbs but some mr16 LEDs cause a problem, some do not – and there is no way to tell. The LED lamps from LEDhut I used cause immediate DAB drop out over 12ft away from a single bulbs. I have four of the Philips ones in the kitchen and there is no problem at all. Both bulbs are sold as being suitable for retrofit and both do light the room but only the cheap ones gave out radio interference. Same fitting, same transformer, different behaviours with different bulbs.

I bought 4 MR16 bulbs from EnergySavingLED.com and they wipe out my digital radio in the room next door. I am just about to send them back as they came with a 3 year warranty. I’ll let you know how I get on.