Zigbee Light Switch, Bulbs and Power


I’ve never worked with Zigbee, however I’m thinking of install 10 x BR30 coloured LED bulbs. The location is in Canada.

Potential scenario:

  • Zigbee light bulb is turned on and off manually by Zigbee light switch.
  • Same Zigbee bulb & light switch are integrated into Home Assistant via Zigbee2MQTT.


  • Does the Zigbee light bulb loose it’s integration to HA if the Zigbee wall light switch is turned off? I’ve recently viewed a YouTube video where it was implied that if a Zigbee light was turned off by the Zigbee wall light switch then the bulb would become “unavailable” in HA until power was restored (light switch turned on). If true, then is there a work around?


  • The Zigbee light bulb be controlled by HA regardless of the position of the wall switch?
  • The Zigbee wall switch turn the bulb on or off, but not take the functionality of the bulb away?

Thanks in advance for any help that can be provided.

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Your questions depends on the wall switch.
If the wall switch is on that actually cuts the power then the bulbs will be with out power and unavailable to HA.
Many wall switches is just switches though and will just send a signal to HA, which can then be used to send a signal to the bulbs to make a software turn off, which means their control circuits will still be powered and available to HA.

The wall switch that cuts the power will have to placed on the mains wires, so it will typically be somewhere where an old wall switch was placed.
The wall switch that just sends a Zigbee signal to HA just needs to be somewhere within reach of the Zigbee mesh network, which can easily be extended with repeaters (Zigbee Smartplugs and bulbs often have these repeater features included).

Hi Wally
Thanks for your response. If I understand what your saying, then I don’t physically connect the bulbs to the switch in the traditional manner (where the switch will control the lights: on or off). Instead I’ll hard wire the bulbs so they have power going to them all the time (i.e. their on all the time). Next, power up the wall switch, but make sure it doesn’t directly control the bulbs. Home Assistant will now control the bulbs. If the wall switch is in the off position, Home Assistant will send a signal to the lights to turn them off (or dim them enough so they appear to be off). When the switch is turned on the opposite is true. Any colour changes to the bulbs with be done through Home Assistant. Is that correct? BTW I’ll be installing a USB Zigbee hub so any Zigbee device can be controlled locally. Thanks.

Your idea about the workings is correct, but your idea about a ZigBee switch is somewhat limited.
A ZigBee switch can so much more than a traditional switch.
Often it has multiple keys and all keys can have multiple functions, like short press, long press,double press, trouble press, and follow up press.

Thanks Wally for the information. You’ve been a great help. You don’t happen to know how I can introduce a music source that will sync up to the bulbs and then have them change colour?

Syncing sound with lights is not really in the scope of HA, but try to look at something like this:

I think it’s overkill to have smart bulbs AND smart switches for those bulbs.
But, if you wish to be able to use switches of any kind to control the bulbs, there is not other way IF you also want to be able to control brightness & color of those bulbs.

I have smart bulbs with traditional switches (existing situation and didn’t want to change that) and never touch the switches anymore since my automations control my bulbs.
By leaving the switches on, the bulbs stay on the network all the time and are controllable.

Hi Nick
These bulbs are going to be in the outside soffit and won’t be going on with any regularity. I can see the advantage of using a traditional (non-smart) switch. Because I’ve never used Zigbee before I don’t know what happens when the power is cut to the bulbs. What happens if I group all the bulbs together and then cut the power to them? When power is restored will they all fall into the same group (I’m not sure if “group” is the correct term to use)? Do the bulbs react like an WiFi based device, in most cases the same IP address is assigned back to the device if using DHCP (100% if using static IP addressing).
Thanks for the help.

Hi, everything depends on what you want to achieve and what you already have (physical switches)

My smart bulbs are controlled by automations/motion sensors so there is no use to do this with the switches.
I do have lovelace buttons though to control them or adjust the brightness (generally also controlled by automations) for a single case.
Very rarely I flip (off/on) the physical switch to turn them on.

If you cut the power for longer time, they disconnect from your network. I don’t know by heart what the limit is for this.
You can create zigbee/HA groups to control multiple devices with one action.

Thanks Nick.
One of my fears is if I cut the power for a long period of time then the bulbs won’t connect up to the zigbee/HA group when power is restored. What I really need to do is get a couple of zigbee bulbs and set them up into a group, then disconnect the power. In my case power might not be restored for months as the bulbs are in the backyard soffit and I don’t go outside a night during winter months.

Do you already have the electricity and switches installed?
In that case, you could leave it as is BUT:

  1. where will you locate the zigbee coordinator and will there be adequate reception
  2. you could leave the physical switches on (time limit for devices to fall off the network is, I think, within a day) and accept a little standby-power

Thats not your biggest issue. Don’t cut the power to zigbee smart bulbs in most cases ever because MOST zigbee smart bulbs being line powered are repeating nodes in your zigbee mesh. Over time other zigbee devices will end up using them to repeat the signal back to your coordinator.

So guess what happens when you cut power to the repeaters?

All hell breaks loose on your mesh. In theory the children left onto he network should start hunting for new parents after about 20 minutes but in most cases theyre using repeaters because they’re too far from the coordinator (zigbee is low power and short range) so comms not only get cut to the bulbs you turned off. But anything downstream.

Sengled bulbs don’t repeat on purpose but don’t use them to work around this issue, just don’t cut power to the smart bulb.

Thanks Nick and Nathan.

Good points made by all. Currently I don’t have any Zigbee devices, but if this bulb project goes well I might add some other devices, which if I cut the power to the bulbs, other devices might not work as part of the mess network is off line.
1.) Currently my Home Assistant is running as a VM on a Proxmox server located in my basement. To this I’ll add a Sonoff Zigbee 3.0 Dongle Plus.
2.) The house is a bungalow and the closest Zigbee bulb will be in a outdoor soffit, 25 - 30 Ft above the dongle and the signal will have to travel through one wooden floor, one wooden ceiling and an exterior wall made of wood and clad in vinyl siding. Shouldn’t be a problem. If need be I can add a zigbee smart plug in the room directly above the dongle. This could act as a mesh point between the dongle and the first bulb.
3.) I’m thinking of using the Sengled Zigbee BR30, Colour, Smart Light Bulbs, as they are cheaper than Philips Hue.
4.) If need be I can add a Sengled (E39-G8C) light switch.
5.) Where the Sengled BR30 bulbs are to go, currently there are 10 x BR30 soft white dimmable LED’s controlled via two traditional 3-way switches (with one having dimmer capability).
6.) Syncing the Sengled bulbs to music isn’t a game changer and really came as an afterthought. It’d be nice to have but won’t stop the project. If I could slowly change the colour of the bulbs automatically every 5 - 10 minuets, that might work.
Any thoughts please feel free to chime in. Thanks again for the feed back.

A dimmer will not work with smart bulbs.
Smart bulbs expect full power at all times or nothing at all.

Hi Wally
According to the Singled Canadian web site the bulbs can be dimmed. Do you think this is a recent upgrade? Here’s the description of the bulb:

“Sengled Smart Multicolor bulbs are the easy way to add colorful, smart lighting to your home. Add the bulbs to a compatible hub and choose from 16 million hues, or tune white light from candlelight to daylight (2000K-6500K). Turn on/off, dim, and schedule using the free Sengled Home app or your voice. Certified with Amazon Alexa and Echo Plus, Google Assistant, SmartThings, and IFTTT.”

Wally’s talking about electrically dimming the load - that article refers to ‘dimming’ by command - the bulb is executing a program to dim itself but power to the bulb never changes.

Okay. Got it. So then if I install the Sengled light switch, use the Sengled app or an integration in HA, then the bulb can be dimmed because a command is being sent rather than a voltage drop (as with a mechanical switch).

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Yes, that’s correct.