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Can Turning Smart Bulbs Off And On At A Switch Damage Them?

If you have a smart bulb installed in a light fitting, it’s easy to forget that it’s a smart bulb and turn the switch off to it – rendering the smart bulb useless. Alternatively you might live with someone who keeps says “you’ve left the room, turn the switches off once you’re done!” (or “it’s daytime, you don’t need the light on“) and flips the switch off. Grr. Whatever the cause, we all know that suddenly killing the power to a computer can damage it – so is the same true of a smart bulb?

Smart bulbs are LED based, which won’t be negatively impacted by turning the power on/off throughout the day via the switch. This will however effectively disable the smart bulb (as there’s no power flowing to it), but it won’t damage it.

Bulb types and damage from turning them on/off

Two LED lights (E14 candles) and a halogen E14 in the middle.
Three lights: two are LED, whilst the other is a halogen bulb.

LED bulbs are fairly popular nowadays, especially throughout Europe where a series of energy saving regulations has made LED bulbs prevalent due to progressively banning certain types of non-LED bulbs.

The majority of non-LED bulbs emit light by using tungsten (the metal) filaments which heat up and ultimately emit electrons – light – via thermionic emission. The two main types of non-LED bulb that you may have in your home or office are:

  • Incandescent/Halogen Bulbs – an initial inrush of current rapidly heats the filament to be white hot, before the current drops back down – but the filament still remains quite hot throughout the bulb being turned on. This heat is what causes light to be expelled out of the bulb, to light your room.
  • Florescent Bulbs – these don’t have an initial surge of current and a super hot filament, however they do have a specific startup routine which heats up the filament more gradually in different stages – almost like various waves of current flowing through the circuit. This is why strip lights (which use florescent bulbs) can sometimes flicker whilst starting up – as the bulb is going through one of many parts of the start-up phase.

As you can tell, both main types of non-LED bulb have a specific start-up process. These consume more current than their normal operation, and they also both work by heating a filament up.

This means that if you’re constantly turning the power on/off to the bulb, you will start to shorten their life because the physical metal (the tungsten filament) inside will slowly but surely be degraded.

A great alternative is LED bulbs – either smart or dumb ones.

Why smart (well, LED) bulbs are fine with dumb wall switches

A dumb UK light switch (single gang) which is in the 'off' position - meaning no power is flowing to the light bulb.
A dumb UK light switch which is turned off.

Smart bulbs are LED bulbs with some added circuity to respond to ZigBee/Bluetooth/WiFi messages

The added circuity won’t get damaged by turning the power on/off – since it’s not like a computer with a hard disk, which could lose data by randomly turning it off.

In terms of how LED bulbs work (whether they are smart or dumb) – they use a p-n junction, which allows for electrons (and hence light) to pass through two semiconductor points. This approach requires much less current and voltage, which is why you often see LED lights advertise “5W, 40W effective” – meaning that they use 5W of energy, but will emit as much light as a 40W incandescent bulb.

Switching your LED bulb on/off throughout the day therefore won’t damage it because there’s no filament to degrade, plus the overall current flowing through it is much lower (sometimes 8-10x lower than the equivalent non-LED bulb).

Heck, lots of LED lights use pulse width modulation (PWM) for dimming – which involves switching the internal power flow in the bulb at high speeds to give a graceful dimming effect.

To wrap up this section, the summary is that LED bulbs can handle being frequently turned on/off at the switch without shortening their lifespan.

Keep accidentally turning the switch off? Disable it!

Whilst it’s good to know that switching the power to your smart bulb off won’t damage it, it can still be annoying to forget that you have a smart light and switch it off at the wall.

This is because if you then want to dim it or turn it back on, you can’t just issue a quick voice command (or go into your Hue/LIFX/etc mobile app) – you instead have to go over to the switch, turn it on, and then issue the voice/mobile command.

It’s inconvenient, but thankfully there are solutions out there. One of them is to explore smart light switches as I’ll explore below, but you have some other options open to you too:

  1. Remove the light switch entirely. This is possibly a bit extreme, and it essentially involves hardwiring the lighting circuit so that it’s always on – and then you either completely remove the light switch, or replace it with a blank face plate. This can be a good option if you know that you’ll never switch away from smart lighting, but it is a bit of a heavyweight solution. It’s also not ideal that you can’t simply turn your lights off/on again (back to dumb mode) in the case where your smart lighting system is having issues.
  2. Cover your light switch with a picture. Hanging a picture or something similar over the light switch can be a good idea, especially if the frame’s borders jet out a bit meaning that the light switch won’t keep hitting against the back of the picture.
  3. Train yourself! It might be easier said than done, however if it’s just a case of someone accidentally turning the switch off by ‘muscle memory’, you should be able to quickly re-learn the new way of doing things! Just be sure to register (whether mentally or by speaking) when you have turned the wall switch off, and eventually you will stop doing it. In theory! If you keep doing it after a few weeks, exploring one of these other three methods may be better.
  4. Physically prevent the switch from being flipped. You can buy switch covers for toggle switches, which work perfectly for this case. Some of them are simple magnetic solutions which clip onto the light switch’s screws, whilst others can be screwed on over the top (and hence these ones also work well for child proofing):
Two examples of light switch covers. The top is a simple magnetic cover to prevent accidental misuse, whilst the bottom is a screw-in cover to prevent accidental and intentional misuse.
Two examples of light switch covers: a simple magnetic cover, and also a screw-in one.

There are a range of solutions here from the more complicated (i.e. re-wiring things so you don’t have a switch anymore) to the simple (i.e. put a quick cover over the switch).

Can smart light switches help?

The other option is to explore smart light switches. There are a range of options here, although some are tied to specific types of bulb (e.g. Philips Hue switches will only work with Hue bulbs).

You also need to be careful because some smart dimmer switches can actually damage a smart bulb. This is because a smart bulb needs fairly constant electrical current going to it (so that even if the light is off and only negligible electric is being consumed, the bulb can quickly spin back up to full brightness as it’s designed to do). Despite this, most dumb dimmer switches and some smart ones will work by lowering the current being supplied to the bulb. This is fine for dumb dimmable bulbs, but not for smart bulbs.

In other words, be sure to investigate your potential smart light switch purchase carefully. Just because you have a smart light doesn’t mean you need a smart switch… in some cases, you shouldn’t have both.

A final note: if the switch does keep getting flipped off

If you aren’t able to modify the wall switch for any reason, you now know that your smart bulb isn’t being damaged by being turned on/off throughout the day. That’s good, but you might be left with the inconvenience of your bright pink Hue color bulb going back to boring white after it’s turned on/off.

Thankfully there is a solution. This does depend on the type of smart bulb you’ve purchased, but Hue, LIFX and a few others support this.

You can basically choose what color and brightness your smart bulb should go back to once being turned back on. In general you can choose to go back to a default 100% brightness warm white, or the last color/brightness setting.

To do this with Hue, firstly make sure that your bulbs are up to date by going to Settings -> Software update:

Screenshot of Philips Hue app, showing the software updates (and existing versions) for a Hue Bridge and also four smart bulbs.
Hue app’s software updates page, showing all my bulbs (and the Bridge) is up to date.

Once they are up to date, go to Settings -> Power-on behavior and choose a specific light, where you can configure exactly what should happen:

Screenshot of the Philips Hue mobile app, showing the power-on behavior setting for a bulb. Options are "Philips Hue Default", "Power loss recovery" or "Custom".
Hue’s power-on behavior for a smart bulb.

This is a very nice feature because you then don’t need to worry about your smart lights being turned on/off at the switch: they won’t get damaged, and they’ll come back on to exactly what you set them to. No harm, no foul!

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