/ 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.

John Inge Nordfonn says:
21 February 2018

Led among other electronics make trouble for Ham operations as well. Interference so we cant use our radios. Plasma TV is the worst


QRM5 -John ?

Paul says:
30 March 2018

I’m having that problem now. I bought my bulbs at protuninglab, an online store. These are the fog lights and they are causing radio interference. I put some ferrite chokes on them today and the situation has improved a bit but still remains as a problem. I’m not sure what to do at this juncture.



Paul Ferrite chokes I know about fitted them to BT call-connect business system units on the input wiring in an engineering factory but the fault persisted coming from high frequency welding equipment locking up the CPU . Radios nowadays have directional aerials for high frequency gain , try moving the radios around . The chokes will probably be wide-band and not so efficient at the frequency involved. If its mostly induced in the ring main then fit a series HIGH QUALITY filter between the mains and the fog lamps.


Paul – I suggest that you contact the supplier and try to get a refund. It might be best to stick with whatever lamps the manufacturer recommends.

Rob Harrison says:
26 April 2018

In a recent European wide test of LED floodlights by two independent working groups, the results were extremely poor. The testing consisted of safety tests and meeting EU interference standards both by technical testing (meeting EU standards) and administratively.

Reference document here http://www.tukes.fi/Tiedostot/sahko_ja_hissit/JA2015-EMCLVD_Results_of_Campaign.pdf

Out of 87 safety tested only 9 met all safety standards and 76% were considered dangerous , posing a shock risk. For EMC testing only 47% met current standards up to 30MHZ and 55% were OK from 30-300MHz. For combined safety and emc/admin’ testing only 5 lights passed both tests.

This is a damning indictment of the way consumerism has degraded the quality of products in general and of government(s) not properly funding the relevant standards authorities to keep poor product from the market.

Solar panel RFI, plasma TV, and PLT(data over the mains) are to other major contributors to EMC pollution. Ofcom do not want to know and have changed their interpretation of what is considered harmful so as to allow their very limited resources to deal with only “danger to life” situations. They take reports of local interference, but very rarely act. Last April new legislation was enacted to specifically address these problems. However, Ofcom don’t seem to want to use these powers.

This is just scratching the surface of the problem of non-compliant product swamping the marketplace in all areas, not just electronics.

Angry Ham,



Rob-As a Radio Amateur (HAM ) you must know the history of the GPO Interference Group which was severely downgraded by HMG allowing CD radio to boom and even ( illegally ) overlap the 27Meg bandwidth range allowed including RF amplifiers over-watting their output etc. This was the start of the downfall of real action being taken by the public to combat this and is part of “Open Britain ” as in third world open . I worked beside a GPO guy who worked in the Interference Group before BT went private separating itself from the GPO , meaning I couldn’t go into GPO canteens and started getting parking tickets . He told me all this was going to happen and he was right . Its part of US globalization now and I dont see any real action being taken unless there is a change of government as the government= big business .

Denis says:
3 May 2018

I changed out five 12V 50W MR16 halogen downlighters for 12V 5W MR16 LED downlighters. Interference swamped my and my neighbour’s FM and DAB. The 12V individual power supply units were rated for a minimum load of 20W so they didn’t match the 5W LEDs. I changed the lot out for 240V GU10 LEDs, a mix of Integral and Aurora. The interference ceased, except for a whisper when a radio was held up against the bulb.
It does not appear to be common knowledge that you should not replace 12V halogens directly with 12V LEDs. Not only does it cause interference but carries a risk due to the power supply driving an incorrect load. Perhaps LED manufacturers should have a warning on the packet.