How To Stop Your LEDS From Flickering, Buzzing, Glowing And Burning Out
Just because LEDs are more efficient and cost effective than other bulbs, doesn't mean they are problem free.
LEDs only provide light when an electrical voltage runs through them. If this voltage is not constant, flickering will happen.
This only affects LED bulbs because others like halogens and incandescent maintain enough heat to cover brief gaps in voltage. LEDs don't.
This should only be a problem when LEDs are installed with incompatible dimmer switches; it shouldn't happen when fitted to a regular light switch.
Why does it happen with dimmer switches?
Standard dimmer switches are designed to operate with incandescent or CFL bulbs of 40 watts or more.
A 40w incandescent bulb is equivalent to a 9w LED bulb, so when you fit your 9w LED into the fitting the wattage comes up short. IT is far below the minimum for the fitting which can cause problems.
How to solve it:
You'll need to get an electrician to upgrade your dimmer switch to one suitable for LEDs.
LED dimmers cost around £15 and an electrician should charge between £35 and £60 to install the switch, so it's affordable to make the change. Don't forget that you also need to make sure that the LEDs you buy are dimmable bulbs.
If you're not sure how to tell the difference between a dimmable bulb and a non-dimmable check out our quick guide on the topic.
Same as flickering - the wrong dimmer switch.
Why does the wrong dimmer switch cause buzzing as well as flickering?
Dimmer switches work by rapidly switching the electricity circuit to the bulb on and off which reduces the overall amount of energy flowing through the circuit and to the bulb. This is why the voltage sometimes has gaps in it which causes buzzing (and flickering).
How to solve it:
Ask an electrician to upgrade your dimmer switch to one that is compatible with LEDs (see the flickering section for estimated prices).
Glowing after switching off
A problem with your electricity circuit instead of your bulbs. Some light switches let through a residue of electricity, even when switched off.
Why does this residual electricity come through?
- The neutral wire in the circuit is not bonded to the earth or the earth wire is at too high a resistance so is therefore creating a small current which is “powering” your bulb.
- There is a tiny pick-up of electricity from cables running alongside each other due to electromagnetic induction. This low level induction from the live wire causes the bulb to glow.
Why does the residue of electricity make LEDs glow and not other bulbs?
The diodes in your LED bulb can use the very low level of current to create light (other bulbs can't do this). Glowing LEDs can be particularly noticeable when light bulbs are fitted with two-way switches, i.e. the same bulb is operated by two different light switches.
Is it a problem?
It won't damage your fitting or bulb, but it can be annoying and will cost you in electricity (albeit a very small amount).
How to solve it:
- Make sure wiring is earthed
- Install a zener diode
An electrician will be able to tell you whether the glowing is caused by the wiring not being earthed properly and fix this for you if this is a case. This should be easy to fix.
If the cause is cabling being too close, you could ask an electrician to install a zener diode which will regulate voltage of the electricity circuit your glowing LED is on.
A zener diode will block any residual voltage coming from the circuit and therefore solve the problem of your glowing lights.
It shouldn't take an electrician long to install a zener diode and the diode itself costs a couple of pounds so it should be a straightforward, affordable job.
Burnout - gradual dimming of the bulb
When an LED bulb operates at a temperature above 60°C. Burnout happens slowly in LEDs - they will gradually lose light over time.
How to solve it:
Buy decent quality bulbs. Good quality LEDs are designed so that heat is dissipated away from the diodes, usually by the fins around the base of the bulb - this slows the rate of burnout.
All LEDs will burnout eventually, but there is a significant difference in speed of burnout between a low quality LED and a high quality LED. It is worth paying a bit extra to ensure your bulb lasts longer.
A note on low quality LEDs
Low quality bulbs are the cause of most problems with LEDs.
What an LED bulb should do vs what most do:
Quality LEDs are designed to last around 30,000 hours on average, but in a recent investigation by Which? many bulbs fell far below this number.
66 of the 230 bulbs tested lasted less than 10,000 hours, despite claiming to provide a minimum of 15,000 hours of light. Poor quality LEDs burnout quickly due to being fitted with low quality semi-conductors and they are also subject to fewer quality controls during the manufacturing process.
Problems caused by low quality LEDs:
In addition to burnout, bad LEDS cause:
- Fluctuations in brightness
- Fluctuations in colours
- Fluctuations in lifespan
- Light fading quickly over a short period of time
Cheap LEDs are also more prone to flickering, buzzing and glowing when switched off.
The only way to avoid these issues is to avoid buying poor quality bulbs in the first place.
How to select good quality LED bulbs:
Most reputable light bulb retailers will only buy certified, tested bulbs.
You can avoid low quality LEDs by sticking to the following:
- Purchase your bulbs from a reputable store - it's tempting to buy cheap LEDs from online auction sites but paying 99p for an LED bulb is unlikely to result in a quality product. This kinds of retailers also don't offer you support and advice if you run into problems or want to return your bulbs.
- For a high quality GU10 bulb you should expect to pay at least £2-£4 although they can cost as much as £9
- Go for branded LEDs - names like Bell, GE, Sylviana, Osram and Philips are synonymous with quality. If some of these brands seem a little pricey speak to your light bulb retailer who should be able to offer an alternative cheaper bulb of equal quality.
If you have any questions about LEDs, the team at Lamp Shop Online are happy to help - just call 0113 8876270.
- Read Lamp Shop Online's Complete Guide to Upgrading Your Entire Home with LED Lights for tips and advice on making the switch to LEDs
- If you have problems with a fluorescent tube then check out our article Troubleshooting Common Problems with Starters and Ballasts in Fluorescent Tubes
- Not sure which wattage is right for your LED bulb? Read our guide Which Light Bulb Wattage Do I Need?
- Find a qualified electrician near you http://www.electricalsafetyfirst.org.uk/find-an-electrician
- For the average costs of services provided by electricians, visit the Which? website
- To find out more information on what a zener diode is and how to fit one, check out this article ‘Why do my LED bulbs glow when off?'
- For more information on how dimmer switches work and why some dimmer switches won't work correctly with LED bulbs, read How Dimmer Switches Work from the howstuffworks website.
Please note: the information in this article is provided as a guide only. We strongly recommend speaking to an electrician before attempting any electrical work yourself. Any links included in this article are for information purposes only and Lamp Shop Online does not endorse the websites linked to.
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