Light bulb not switching off

[John Malam]

I've fitted a new bulb on our landing -- 60W LED GLS. It won't switch off, but just dims down a bit. Comes back to full brightness when switched on. (In other words, it's always 'on' even when the switch is 'off'.)

Have I used the wrong bulb type?
Is there a permanent trickle to this light that didn't affect the previous bulb?
Do I need the wiring checking?
Is it something else?

Thank you.

 

[Midwest]

Led lamps can suffer from this effect of flashing or glowing dimly, when the lamp is turned off (google that phrase), for the reasons as described, or if the neutral to the lamp position is switched, as opposed to the live.

You could have your wiring checked, but I suspect if you try a different lamp by a different manufacturer, the issue might be resolved.

 

[Taylortwocities]

Thanks for all the comments -- really helpful.

I've swapped the LED over to another fitting in the house (1-way) and it switches on/off without any 'after glow'. So, it looks like it's the 2-way fitting that is the problem, not the bulb.

Does it mean the fitting is faulty and should be checked for safety?

Over the years, when a bulb blows, it's nearly always been the one attached to this fitting.

It won't be the fitting itself, but probably the fixed wiring in the house. This problem is often seen on two-way lighting circuits and those that are not properly earthed. It is usually caused by voltages from adjacent circuits being induced into the lighting circuit.

As above, your solution is to fit a snubber or try a better make of LED lamp.

 

[Taylortwocities]

Thanks for all the comments -- really helpful.

I've swapped the LED over to another fitting in the house (1-way) and it switches on/off without any 'after glow'. So, it looks like it's the 2-way fitting that is the problem, not the bulb.

Does it mean the fitting is faulty and should be checked for safety?

Over the years, when a bulb blows, it's nearly always been the one attached to this fitting.

It won't be the fitting itself, but probably the fixed wiring in the house. This problem is often seen on two-way lighting circuits and those that are not properly earthed. It is usually caused by voltages from adjacent circuits being induced into the lighting circuit.

As above, your solution is to fit a snubber or try a better make of LED lamp.

 

[Deuce]

Some LED lamps have better electronics that adapt far better to inconsistent voltage, and have a better threshold for when to turn off if the voltage is very low (say 20v or less).

Also are there any dimmers on the lighting circuit? They can mess up LED anytime they're in use.

Perhaps easiest thing is to pop to screwfix and buy a multi-meter and just test the output of the light fitting. They sell one for only £10.99

Experiment with different combinations of lights on/off on the same circuit and test the fitting with each combination to see the effect. It's well worth doing as whilst it's probably just capacitive coupling from a two way switch (in which case you could see a few volts when the fitting is 'off'), it could also be an insulation resistance problem (you might see higher voltage when 'off' and potentially lower than mains voltage when 'on'), which is more of an issue and would demand proper investigation. Either way some basic test results will be the start of the solution.

 

[Spoon]

Also are there any dimmers on the lighting circuit? They can mess up LED anytime they're in use.

We are going to get lots of posts about 'faulty bulbs' or 'flashing bulbs' soon, as they have banned halogen lamps and want everyone to go LED. All these cheap dimmer switches are going to keep the forum busy.

 

[buzzlightyear]

We are going to get lots of posts about 'faulty bulbs' or 'flashing bulbs' soon, as they have banned halogen lamps and want everyone to go LED. All these cheap dimmer switches are going to keep the forum busy

normal halogens are glass and metal .and can be recycled not the led
with all the electronics inside .send then back to china and ask them to recycle them .I had to replace some customers led lights the glow in the dark ones . GlS type .

 

[Spoon]

normal halogens are glass and metal .and can be recycled not the led
with all the electronics inside .send then back to china and ask them to recycle them

Not sure if the reason is recycling, energy efficiency or both.

 

[Deuce]

We are going to get lots of posts about 'faulty bulbs' or 'flashing bulbs' soon, as they have banned halogen lamps and want everyone to go LED. All these cheap dimmer switches are going to keep the forum busy.

Skip forwards 10 years and I can see lighting circuits being ELV instead of mains. There is arguably virtually no point in mains voltage as it is, given the bans on traditional bulbs and all the fuss and flap about kitchen/bathroom lights. Shops have used ELV for years so it's well established.

Personally though I have a lot of cut glass light fittings in my home, and they look great with single point light from a filament, but nowhere near as good with LED bulbs that have multiple light sources within the bulb. I guess once the stocks of traditional bulbs runs short they will demand a premium on ebay - I should stock up now