When it comes to smart home, smart light switch should include in your purchase list, as they not only make your house more convenient, but safer.
You can also control smart light switches from your smartphone, or through a voice assistant like Alexa or Google Assistant. You can also schedule smart light switches turn on and off at a set time. Besides that, you connect smart light switches to other smart home devices, and program them to turn your lights on. For instance, the bathroom light turns on when a motion sensor activates.
What You Need to Know Before Buy a New Smart Light Switch?
One common issue that new smart home users face is that their existing light switches don’t include a neutral wire when they trying to install some smart switches to control lighting. There are a few options for installing smart switches without a neutral wire, but first let’s check to see if you have a neutral wire.
What is a Light Switch without Neutral Required?
A light switch without neutral means that to have the power source wiring enter the light fixture directly and the switch is used to complete a circuit. In this case you will not have a neutral wire and your existing configuration will look like this:

The reason that some smart switches won’t work in this configuration is that the switch is breaking the circuit when it is off so power is not flowing through the switch. Smart switches require a source of power because they are always communicating with a hub. If the power is cut (because the switch is off) the smart switch will not be able to receive instructions from the hub.
What is a Light Switch that Required Neutral?
The way to wire a switch with neutral is to have the power enter the switch box and then proceed to the light fixture. In this case, the neutral (white) wires are connected inside the switch box. The switch still breaks the circuit, but in this case the smart switch can tap into the neutral wire to keep power flowing through the switch – the electronics in the switch still break the circuit to the light, but the switch maintains a circuit so it is always receiving power. Here is a diagram of a standard switch with a neutral wire:

A smart switch can simply tie into the white neutral wires to complete the circuit and get a source of power to keep the radios in the switch working at all times.
What To Do if Your House Doesn’t Have Neutral Wire Installed?
Option 1 – Run a Neutral Wire
If you want to use smart switches and don’t have a neutral wire in your switch box, you can hire an electrician to run a neutral wire between the light fixture and the switch. You can also have an electrician rewire the switch and light fixture, which is potentially more expensive. Either way, running a new wire inside the walls and ceilings of your home may be too much trouble.
Option 2 – Smart Switches That Don’t Require a Neutral Wire
There are dimmable smart switches on the market that can be installed without a neutral wire. The key is the dimming feature, which turns the flow of power between the light and the switch down to a slight trickle. The flow of power is not enough to activate the light bulb, but it provides enough power to keep the switch communicating with your smart hub.
However, it is very important that you confirm that your dimmable smart switch will work with the type of light bulbs you plan to use – many will only work with outdated incandescent bulbs.
Here is the smart switch that don’t require a neutral wire. We recommend the Xiaomi Aqara Smart Wall Switch Single Fire Version— we have these installed in our setup and they are working very well.
Smart Switches That Don’t Require A Neutral Wire
- Brand: Xiaomi Aqara
- Model: QBKG04LM(Single Key)
- Wireless Type: Zigbee
- Input: 220V~, 50Hz for single live line (Without Neutral Wire)
- Operating temperature:-5℃-+60℃
- Load range: no more than 800W / each, minimum: 3W energy saving lamps / 5W LED lights / 16W fluorescent lamps
- Brand: Xiaomi Aqara
- Model: QBKG03LM(Double Key)
- Wireless Type: Zigbee
- Input: 220V~, 50Hz for single live line (Without Neutral Wire)
- Operating temperature:-5℃-+60℃
- Load range: no more than 800W / each, minimum: 3W energy saving lamps / 5W LED lights / 16W fluorescent lamps