Light Bulbs Keep Blowing in 5 Bulb Stair Light Ask questions and find answers to many subjects relating to electrics and electrical work

[Oggie8]

At the top of our stairs we have a light fitting which carries 5 bulbs. This is controlled by a two way switch at the top and bottom of the stairs. We have similar fittings in the Lounge, Dining Room and Hall but obviously with no two way switching.

The bulbs in the stair light are forever blowing and I am at a loss to know why. Although we probably use this fitting more than the others we do not have anywhere near the same number of failures on the other fittings. Indeed the number of blown bulbs in the lounge, hall and dining room and hall has, ten years, been in single figures.

This suggests to me that there is a problem on that particular circuit(the stair light circuit)

I hasten to add that we are not constantly switching the stair light on and off frequently.

Can anyone offer any suggestions or advice please.

Thanks

[Mr White]

If there was "a problem on that circuit" then all the other lights on that circuit would also have a problem. Landing lights are usually on the upstairs lighting circuit.
You do not say what type/voltage the lamps are, so I can not be specific.
Lamp failure is often due to bad connections, cheap lamps or poor/failing power supply.

[Oggie8]

What I was trying to say is that my assumption is that there is a problem relating solely to the light on the stairway otherwise I would have assumed, as you say, that other lights on the(upstairs) circuit would have been affected.

[ericmark]

Bulbs can fail due to spikes on supply, which can be due to a bad connection either to whole house or a circuit within the house, the surge protection unit should get rid of the spikes, but since moving from tungsten to compact fluorescent then LED the number of failures has reduced, average was a bulb a fortnight, but since moving so now nearly all LED and SPD fitted I have had one LED bulb fail.

I was interested to see what was inside so opened it, found a dry joint, re-soldered it, and put it back in use. I had some 0.58 watt G5.3 MR16 lamps fail, but they were really toys, and a replacement for a fluorescent tube, and that is in 6 years.

Inside an LED bulb there is a driver, this can be a simple resistor, a capacitor, or a pulse width modulated controller, I would guess the fluorescent tube replacement was PWM driver and likely more likely to be damaged with spikes.

In the old days of tungsten I found dimmer switches made lights last longer, however when the quartz came out, they could not be dimmed without shorting the bulb life, so most my dimming switches went.

You have not said what type of bulb, the G9 quartz needed a cover to stop hot bits falling on the carpet, all quartz lamps need to be behind glass both to stop harmful rays and to retain hot bits, but when replacing the quartz with LED the covers can cause the LED to over heat.

So what sort of bulb, have you got a SPD fitted, and what sort of switch.