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Your view: do LED light bulbs interfere with radios?

Multi-coloured leds

When we looked into the unusual issue of LED light bulbs interfering with DAB radios, we found that the stories were true. So we asked you to share your experiences so we could see how many of you were affected.

We sent a number of cheap, 12V LED bulbs to our lab for testing. And we found that when a digital radio was placed within a few metres of the switched-on bulbs, the signal went fuzzy. Within a few centimetres, the signal cut out altogether.

We asked you if you’d had similar experiences, and 2Dears was one of many who told us they had:

‘In November, we replaced 9 lights in the kitchen with 4.3w MR16 warm white LEDs for use “with an existing Lv transformer”. The DAB radio in the adjoining dining room stopped working immediately the lights were turned on’

We also heard from commenters like George who were having trouble with their FM radios:

‘Our FM kitchen radio gets a hiss over the speech (to the extent that BBC R4, our usual channel, is almost unusable) when the LED spots are on.’

John Dalton has a similar issue:

‘I tried to be green and bought some 12v MR11 LED spots for our kitchen downlighters. Switched them on and Radio 4 went to white noise on the portable VHF FM radio on the kitchen table.’

Shining a light on the problem

David Lewis had a big problem with LED bulbs, but he managed to find a solution:

‘I purchased Ikea lights (6 x 12v halogen bulbs) per 8m run of wires, plus transformer. With the lights on there was no interference of radio reception. I replaced the halogens with 5watt LEDs and replaced the transformer with the appropriate driver.

‘From then on – disaster. Switch one set of lights on and the station would be interrupted by a series of loud plops. Switch two sets of lights on and the tuner would cut out completely. Today, I replaced the indoor aerial with an external five element Triax DAB aerial. Problem solved. Superb reception with any number of LEDs on.’

A number of you experienced problems with electronics other than radios, like Keith:

‘I have two TCP 6W LED GU10 bulbs. The problem I have is when they are switched on and you stand near them, I have a high pitched whistle in my digital hearing aids.’

Tonyp isn’t too hopeful for a resolution, but we liked his metaphor so much, we’ve given him Comment of the Week!

‘There is little scope to make radio receivers less sensitive to this type of interference. The problem is that the lights are radiating energy at the frequency being received. Removing the interfering signal is rather like trying to remove the milk from a white coffee – possible but difficult and rather expensive.’

Looking on the bright side

But we’re pleased to report that a number of commenters, like Graham Pickworth, have had no problems:

‘I have six Aurora brand LED GU10 6watt 3000k non-dimmable light bulbs in my kitchen, purchased from Amazon. There is also a Bose VHF radio within 64 inches of the nearest bulb and I get no interference at all. I also have a Roberts DAB radio which I held up to within about 2 or 3 inches of one of the bulbs. Once again radio reception was perfectly clear.’

Finally, Wavechange had an interesting idea to help shoppers find the right bulbs:

‘LED lamps are expensive and the only way to be sure that interference will not be a problem is to test them in your own home. Perhaps ”bring a bulb” parties could be a new social event to help householders find out which LED lamps to buy.’

neil ackerley says:
25 November 2014

I reported the problem to ofcom over a year ago and they agreed that the drivers were 40dB worse than conformance. The drivers were stamped CE. An acredited emc testing house state that doing so is fraudulent. I got the drivers changed free of charge and ofcom with trading standards are condideting prosecution

Neil – I do hope there is a successful prosecution. I wonder how many of these dodgy drivers are in use under different brand names.

I am very concerned about the UK being flooded with substandard products, some of which are unsafe. Many assume that a CE mark is an indication of safety and quality, so the mark can engender a false sense of security. We need independent testing funded by manufacturers. It is obvious that Trading Standards is unable to pursue every issue that is reported to them.

Prpoerly used – that is by reputable companies – CE marking is an assurance of compliance with relevant EN standards, usually safety and somethimes performance. However, like many things, unscrupulous suppliers and importers can, and clearly do, use it fraudulently. As they can with ENEC or Kite marks. Even if independent testing were instituted – which I regard as impractical because of the scale required – unscrupulousness and fraudulent claims would continue. The only ways are properly policing goods (Trading Standards, but also industry trade bodies who lose business to fraudulent products) and placing sanctions on importers who distribute defective products.

I appreciate this Malcolm. The reputable companies would, I expect, comply with standards anyway. Unscrupulous suppliers and importers are unlikely to pay much attention to standards unless something is conspicuous to retailers or potential purchasers. It would take a great deal to persuade me that CE marking has any real value. Self-assessment of compliance with standards has a formative use but for assessment to be respected outside an organisation it has to be independent assessment. Independent assessment will cost companies money, but would give consumers more confidence in their products. I don’t believe that independent testing is impractical at all.

Excellent job Neil.

I think we … I mean the Consumers Association [ of which I am a shareholder] should be giving commendations to those consumers who go the extra mile and help everyone.

SMK would have been proud of you.
Sheila McKechnie become head of the Consumers’ Association, campaigning on a wide range of issues, often using headline-grabbing stunts.[3] In 2001 McKechnie said: “I am a fully paid-up member of the awkward squad and will remain so for the rest of my life. No government would ever feel entirely comfortable with me or the association because we are both fiercely, fiercely independent.”[1

Dieseltaylor wrote: “I would agree but for the fact that they are being sold without the information that isnecessary to the public. Anotherwords the supply chain and media and government are all extolling the virtues with out highlighting that there are pitfalls. Which? itself is guilty of not mentioning radio interference as downside.”

I hope Which? will tell us more about DAB and FM radio interference next time they test LEDs. There was not problem with the lamps tested this time but interference should be mentioned as a possible drawback of this type of lighting. We need to know where to get decent advice.

I have trawled the websites of several well known manufacturers and retailers and there is precious little comment about radio interference. Tell us about the good points and ignore the bad. Very much like advertising – divorced from reality. Until this year I wondered if interference problems were uncommon but from asking around, some have problems but others don’t.

I did not know anything about the government extolling the virtues of LED lighting.

Justin Needham says:
25 November 2014

I’d be very surprised if “Which?” did anything like that, and there are so many countless combinations of gear, it would be little practical use. (It’s the combinations of LED’s and random old drivers which is probably the largest culprit). “Which?” won’t be testing dusty old drivers which have been in the loft for 15 years..

“Which?” is IMO a pretty lax and superficial these days, and scarcely worth the bother. My Mother in Law still buys it, but it rarely seems to serve much useful purpose.

neil ackerley says:
25 November 2014

NO NO NO, LEDs are not constant current devices. The amount light emitted is roughly proportional to the current flowing and this is roughly proportional to the applied voltage. Below a certain voltage no current flows and above a certain voltage the LED will draw too much current and will blow like a fuse.

For a given light output a specific current is required. This should not be confused with saying the devices are constant current.

I wish more people could grasp this, Neil. Of course with LED lighting, rather than having a DC supply we have a pulsed supply – hence the interference problem – which I presume enables a higher light output and less heating for the same amount of power.

Neil, a typical power LED chip operating at from 1W to 3W will have the following electrical performance:
Forward current 350mA, forward voltage 2.75V, 700mA / 3.00V, 1000mA / 3.1V. The driver required to operate it is a constant current output device.
It requires a particular current to produce a given light output and the higher the current driven through it, the higher the light output and junction temperature.
The driver type required will depend upon any additional on-board circuitry. What is referred to as an LED domestically usually incorporates more than just the basic chip. You need the right driver to match the LED. So if current-controlling electronics are part of the LED component then you will use a stable voltage supply to operate it.

I think you and Neil are at cross purposes. Varying the forward current in your example will vary the brightness of the LED chip.

12V LED lamps such as the MR16 type are designed for use on a 12V nominal supply. As far as I know there is no need for a stable voltage and some work fine on transformers designed to operate multiple halogen bulbs. With the lower load of the LED lamps, the supply can be well above 12V in this case. Unlike a chip, which would demand DC of the correct polarity, some LED lamps seem happy with an AC supply and they are not polarity-conscious on DC. I can’t imagine there is any very sophisticated electronics within the confines on an MR16 lamp.

wavechange – most probably! I was commenting on the characteristics of the raw LED chip. Arrays of these are often used with appropriate current drivers in the commercial world. What we see domestically are usually arrays of LED chips that include the current-controlling electronics, that may be driven from a stable voltage source – low or mains. Decent electronics should be able to deal with some variation in voltage.

Some time ago I was playing with some LED lamps that will run happily from 10-30 volts. They include spike protection. The owner tells me he has had no failures so far, and I am not surprised. I must find out whether or not they create radio interference.

For those that are far more technical than I – I get this emagazine sent daily and some of it is interesting. This is highly detailed article and tends to suggest that LED lights are not a simple plug and play item even for mains voltage.


This article when I first read it was an interesting insight into how people working with LEDs were unaware of some of the results:

Anyway I hope the links from here are of interest.

Don Bradfield says:
25 January 2015

Last November I had Led lighting installed in my kitchen, bedroom and 2 Bathrooms.
When any of these lights are switched on the DAB radios lose their signal.
A friend has told me it is because they must be cheap inferior lights and the transformers
in the units have nothing to do with the problem. Not being led educated I am at loss what to do.
If I changed the bulbs which are Amitex AX248/GU10 4w CW 50 would this solve the problem?
I don’t want to have all the complete fittings changed. I regret having the lighting changed and had no idea that there was a problem with this sort of lighting, otherwise I would not have had the work done. If anyone can help me I would be very grateful.

p90don@btinternet.com says:
1 February 2015

I have solved my problem with the LED DAB Radio. as described in my previous comment.
I have changed all the bulbs with another make of bulb and hey presto DAB again.
the original bulbs had the ce mark on them . the new ones tho made in china, as said work
well. My advice from a none technical person to anyone having LED lighting fitted is to try your DAB radio after the first LED is installed, before the installation is completed.

Richard says:
11 February 2015

We’ve got an Ikea LED bulb in a bedroom which is located below the TV aerial and when it’s switched on, it wipes out some DVB TV channels.

The problem is, normal light bulbs are just a piece of wire which gets hot and gives out light and heat. Simple. The only interference you may get would be caused by electrical arcs when switching on or off.

LEDs themselves don’t generate interference, when they have a steady DC voltage applied, but a power supply of some sort is required, to convert the 240V AC mains to the correct DC voltage.

The most energy efficient way of doing this is with a switch mode power supply, which chops up the mains at a high frequency, smooths it and feeds it to the LEDs. Unfortunately, this produces radio interference at the switching frequency and its harmonics.

It can be difficult to kill this interference completely, especially with such a cost-driven and compact product. Also, the limits for radiated and conducted emissions aren’t zero, so a nearby TV/radio antenna will pick them up at a level which will cause problems. The wiring in your house will be transmitting anything chucked out back up the line by the tiny power supplies in the LED bulbs. More power supplies = more interference.

So, the moral of the story is, if you don’t want radio frequency interference, stick to good old fashioned filament lamps (which don’t waste energy as headlines suggest, as the “waste” is heat, which just goes into your home), with conventional transformer-based power supplies (which, again, “waste” energy as heat).

Cheap (basic) switch mode power supplies will always chuck out noise – and brand names are no guarantee that they’ll be better than the rest.

Richard is correct. Radio interference obeys the ‘inverse square law’ and as the radio aerial becomes closer to the lamp, interference will become much greater. This is easy to demonstrate with a portable radio. It’s not a good plan to have a radio on a bedside table beside a LED or CFL lamp.

At short range, it is possible that interference can be picked up via the circuitry rather than the aerial.

John says:
24 August 2015

I can second all of this. I tried a genuine CE marked Phillips LED and Radio 4 DAB was wiped out.

The two posts above (Richard and wavechange) describe the physics well. There are lots of VHF emmissions from the voltage changing circuitry. The problem is particularly bad in areas with a poor radio signal. I recently moved from Belfast to Ipswich and cannot now use my VHF radio with the LED spotlights on in the kitchen because of the hideous hiss. I have a similar problem with the bedside radio alarm which is close to a compact flourescent bedside light. My DAB portable works in some positions but cuts out if people move around. Repositioning leads to any appliance near the radios changes the reception, so the interference is both in the house wiring and airborn radiation. I am sure that a good directional aerial, preferably on the roof, would cure the problem.
I wonder how much of the problem is down to rubbish electronic production? I have already had circuitry in one of 6 LED spotlights fail. The LEDs were removed and work fine at about 10volts. I have also had several compact fluorescent lights fail. One gave a loud bang with a blue flash near my ear as I walked past the fitting. I dissected the more recent failures. All showed signs of burning in the circuit boards and many of the components had dry solder joints. These components were loose and could be pulled out of their solder. I suspect that few of the 240 volt (mains) LED lights will survive the claimed 25,000 hours before the circuitry fails. The actual LEDs will probably last a lifetime.

Hi Hugh – I’m glad I’m not the only one who dissects failed lamps. 🙂 With automated soldering, dry joints should be a thing of the past except where wires are manually soldered onto circuit boards. Other likely reasons for failure include components being killed by overheating or lack of protection from voltage spikes.

DAB radio can be confusing because as the interference level increases or the signal decreases the radio just cuts out, rather different from an increasing noise level on FM and AM radio.

LED chips can indeed last a very long time providing that they are not over-driven to try to maximise light production, or overheated.

It would be very interesting to compare the components in a well known brand of LED bulb and a cheap one. I fear that there might not be much difference in some cases.

There is a more active Convo on LED interference that may be of interest. Search for: ‘The energy-saving LED bulb that switched off the radio’

Hi Wavechange. Regarding the quality of mass soldering, it was the large components, especially capapcitors, that were loosest. I wonder whether flow soldering was used at any stage, because putting too many circuit boards through too close together could cool the solder, or dirty oxidised solder (or component leads) might not wet properly. The temperature/rate problem also applies to hot-air systems to melt solder paste. It was the tiny surface mounted components that had vapourised. The components in compact fluorescent lights and mains LED lights look very similar, I think they are all made in China.
My daughter had a mobile phone fail after 1 month. The problem was massive corrosion inside a connector (display plug/socket). It looked like flux not washed out and causing corrosion, but carphone warehouse said “water damage”. There was no trace of damp or stains anywhere else. That was made in India.

I don’t know much about commercial soldering, Hugh. In my experience it very rarely causes problems unless there is a cause such as intense local heating and oxidation or large components have not been secured and have been subjected to vibration. Decent rosin flux should not cause corrosion. I have home-made circuitry built over 30 years ago and that is still fine, irrespective of whether or not the flux was removed.

I have looked at the circuit board from an old Tesco CFL and while I have seen better soldering, it is perfectly adequate and there is is no sign of corrosion or overheating of components. It looks as if you have seen examples of poor standards of construction – something I have only read about. With the phone you mention, the technician may have had little experience or understanding of the nature of the damage.

The only type of LED lighting circuitry I have examined is small circular boards with components on one side and LED chips on the other, intended for replacement of MR16 downlighters. They were from a specialist supplier, designed for 10-30V input and with voltage spike protection. The build quality looked excellent. I suspect it would be difficult to inspect the innards of most LED lamps.

Hugh_F, you might also be interested in the parallel conversation “The energy-saving LED bulb that switched off the radio”.

Hugh F – Your mention of your daughters mobile phone failing is very much of interest as they cost considerably more than a lamp.

What was the make and model?
Where you successful in your claim?

I cannot be sure of the manufacturer, I think it was motorola. I did not have any way to rebut the retailers diagnosis of water damage. The corosion was so bad (the metal was black and crumbling) and so localised that I still think it was some sort of chemical from the manufacturing process trapped within the component and not properly cleaned or dryed out which was hygroscopic- taking up moisture from the air. I was told that using the phone in misty conditions or rain or snow, or going into a warn house with a cold phone and getting condensation in it could all invalidate the warrenty. In fact anywhere you might want to use a phone really!.

I have had informative and helpful replies from the LIA (Lighting Industry Association).
“Your suggestion that the LIA test products where we anticipate a problem and inform Trading Standards of the results is exactly what we are doing. We have also introduced a ‘Performance Verified’ scheme where manufacturers can have products tested and the full set of results is posted on a website so that any part of the supply chain or end user may see exactly what the product achieves in terms of performance and life. Take a look at http://www.lialabcert.org.uk The Performance Verified Scheme is new and there are a large number of products going through test which will appear on the site soon. It’s open to all lighting products and yes, manufacturers agree to have their results published. Should a product fail or perform badly it’s up to the manufacturer whether they withdraw the product and make the necessary improvements. The key thing is that these manufacturers are keen to set themselves apart from the poor quality products and go public with their results.”

Short answer: Yes, ELV (Extra Low Voltage 12v) LED lighting can cause DAB, Wi-fi etc to degrade under this sort of circumstance:
You have 12v Halogens, say 50w (ish) and you replace them with much lower wattage LEDs, say 5w.
Why? The answer lies in the transformers that step the 250v down to 12v. The output of the transformers will be something like 20w-70w (have a look). Which was dandy for the old halogen, but the LED is operating outside of it’s ability and it’s complaining.

Two solutions. Either buy new transformers which are correctly rated. Or (and this proved to be cheaper in my case) bin the 12v bulbs and transformers and use 250v kit instead. It’s quite straightforward.

The advantage of the 250v approach is that Low Voltage (250v) LED lights outperform 12v in terms of light quality and reliability now. Also cheaper.

I have just replaced some Enlite led lights with some new ,supposedly better, led lights. The old lights were fine but the new ones when on silence the DAB radio, These are expensive lamps (£24). I have called the technical department of Aurora(I think Enlite is a brand) and they are trying to resolve the issue but it seems the new lights do not have or have different driver which maybe the problem.

18 January 2016

Just decided to convert my halogen and incandescent bulbs to LED lamps. Depending on what circuit the LEDS where on got a lot of interference on my kitchen radio when the LEDS were on. I also noticed that when I turn on my plasma tv that the picture would not appear but got vocals. I, m using three different manufactures of LEDS ( Philips. cree, and ecosmart) I,ve been in the electrical business for 45 years. When ballast manufactures first came out with electronic ballast for the new energy saving fluorescent lamps some manufactures were faced with the same issues i.e ballast humming and static on radios and tv,s. They eventually solved the problems by installing RFI filters in the ballasts. If my issue persist will be forced to replaced the LEDS that are causing my problems.

Today’s news from Which?:
“£1 LEDs launched at Poundland. Poundland’s launching a range of LED light bulbs. ……………………LED bulb prices continue to fall The LED market is moving fast. Poundland’s launch comes at a time when technological development and rising demand has led to more retailers stocking LED bulbs. ”

Which? have not tested these but, when they do, will they check them out for interfering with radios and other devices? It seems an important part of LED characteristics that Which? do not cover. Or has it now changed?

Read more: http://www.which.co.uk/news/2016/05/poundland-launches-new-led-light-bulbs-440702/ – Which?

Astonishingly it does not mention radio interference at all which surely is a disservice to all. What ****** use is a consumer body that does not tell potential buyers that there is a potential major downside.

Astonishing behaviour hardly seems an adequate reflection given the hundreds of posting about this problem that has afflicted so many.

In one of the reports in the Which? magazine it was mentioned that the lamps tested did not interfere with DAB radio. No mention of FM, which many people use. I may be wrong but I don’t think Which? has tested any 12v LED lamps, where interference can originate from the lamp and the power supply (driver).

With many products we can avoid problems by purchasing well known brands but this does not seem to be the case with LED lighting. I’m waiting for reliable advice before spending money on products that may interfere with my radio listening. The one that I did purchase – an Osram lamp made in Europe – caused FM radio interference and has been consigned to the downstairs toilet. At least it is still working, unlike many LED lamps sold for household use.

Please will Which? arrange a test for a wide variety of LED lamps, including 12V types (and drivers), often used in downlighters (e.g. MR16 type).

But it’s good news that the price of LED lighting is falling.

wavechange – I understand your sentiment but surely Which? highlighting really cheap LED’s will lead to the problem being aggravated as the odds are they will sell-out and many many more people will be affected.

The fact that Which? will have been material in encouraging people to buy them whilst the technology is so problematic, without mentioning these downsides, seems particularly odd.

On the other hand it might raise awareness of the problems and cause more people to report problems. I wonder if our time would be better spent writing a letter for publication in the magazine.

When halogen bulbs are phased out to save energy, LEDs will be the only direct replacement, so hopefully the problems of radio interference and premature failure will be addressed soon.

Promoting “cheap” LEDs is likely, in my view, to multiply the problems that some LEDs have. The attention will, I expect, be focused on the cost to Poundland, but what attention will the manufacturers have devoted to interference, to quality of components to ensure long life, to quality of the LED chip to get a decent (and efficient) performance. All LEDs are not the same! The reputable manufacturers sort their production by “binning” – batching up those with similar colour, similar light output but those bins will cover a range of colour and light output (and efficacy).

‘d rather have quality LEDs that last, don’t interfere, are efficient, safe and have a good colour appearance and rendering, rather than cheap. Will Poundland LEDs stack up?

In the same way that all food needs to be safe irrespective of price and source, all LED lamps need to comply with the current EMC standards. It’s clear to me from posts on Which? Convo and elsewhere that buying ‘reputable’ brands is not a solution to this or the durability issue. Price is an important consideration for many people and we need to make sure that they can buy products fit for the purpose. Maybe we need to sort out the basics as the first priority.

I bought a number of LED 120mm diameter panel ceiling lamps via eBay. They gave me a deal of trouble with stereo FM radio and I complained to the supplier who *said* he passed these comments on the the manufacturer. A replacement set was sent with an assurance that the problem was solved. See this Youtube video for the ‘improvement’

Frank Allender says:
30 November 2016

I have today installed COB LED lamps in the kitchen and other contributors I find that it kills my DAB radio. The lamps I installed where not cheap, £17 each, and the package includes a driver. So, no question of old drivers or driver incompatibility. Right now I’m waiting for a response from the manufacturer but would advise anybody considering installing LED lamps to purchase a single item in the first instance and test at home to see what happens.

Manufacturers are often helpful, but it is the retailer that is legally responsible for dealing with unsatisfactory goods. You are absolutely right about testing a single lamp before buying a set.

I changed from MR 16 Halogens to LED’s. The first bulbs (GVOREE GU5.3 Bulbs MR16 LED Light Bulbs 5W LED) and transformers (LED Driver Transformer 240V – 12V) interfered with my DAB radio. Everytime I switched any of the 10 lights on the radio went off. Also the bulbs claimed to be 50W equivalent (they were not). I would say 40W maximum, so they were not bright enough. That is when I decided on these bulbs (Simpome 6W MR16 LED Light Bulbs (5 pack), GU5.3 LED Bulbs, 3000K Warm White, Equivalent to 50W Halogen) from Amazon. This was to increase the brightness only.

At the same time I also decided to buy (Topnisus [Pack of 10] Clip-on Ferrite Core Ring) to stop the interference. I fitted the bulbs before the ferrite rings had arrived and found just by using this bulb (with the LED transformer) solved the DAB issue. No more interference and brighter lights (definitely 50W equivalent.

So top marks for this bulb. and when it comes to replacing my other halogens I will order these again.