/ Home & Energy, Technology

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.’

Comments
Guest
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

Guest

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.

Guest

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.

Guest

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.

Guest

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

Guest

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.

Guest
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.

Guest
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.

Guest

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.