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Guide To Smart Relays

Guide To Smart Relays

Think of a relay as a light switch.

Instead of a physical switch on the wall though your switch is now on the smartphone app.

Once triggered it closes the relay, like a standard wall light switch, and turns the light on.

They can be controlled from a smartphone, with scenes & timers as well as with voice control using Amazon Alexa or Google Home.

Smart relays will find their way into most smart homes, they are easy to install, cost effective and are a vital part of smart homes.

Smart Relay Use Cases

There are numerous uses for smart relays from lighting to power, we’ll cover a few of the main uses here:

Lighting: The most common use for smart relays is to control lights. Any form of on/off lights including LED strips, garden lights and standard house lights can be controlled and automated with a smart relay. 

Smart relays are also a good way of adding control to lights that have no control, for example if you have power to a kitchen island you can add a smart relay without needing to get a switch wires back to the wall. You can then control the lights from smartphone, voice control or by linking to a compatible smart light switch.

Fans: In a normal bathroom the extractor fan would switch on with the light switch. Once you go smart you can then expand on this with the relay. 

After turning the lights on the fan will automatically turn on, run for a preset amount of time then turn off. 

Even better, you can program the fans to only work between certain hours, so in the middle of the night the light will come on but the fan will stay off!

Garage Doors: Some relays feature a low voltage trigger (Fibaro Smart Module or Lightwave Relays) which can open your garage doors or gates via smartphone, voice control or timers. 

Simply connect the relay across the volt free trigger on your garage door or gate controller and you can open and close them remotely.

Types Of Smart Relay


There are a few different WiFi relays including an indoor and an outdoor relay.

They connect between a power supply and a load such as a light then provide control via the smart app.

Most WiFi relays do not have switch inputs so once wired in they can only be controlled by WiFi using the smart app, timers or voice controls.

They are useful for automatic lighting where no switch is required or applications where you’re using voice control only.

If you have a WiFi smart light switch in a room you can map the button in the app to control the WiFi relay, so in certain situations you can control the relays wirelessly from a wall switch.

Z Wave 

Z Wave relays such as the Fibaro switch 2 can be used to control lights, fans and appropriately rated appliances.

These relays also feature a switch input allowing them to easily be controlled by a hard wired switch making them commonly used for controlling lights.


You’ll also find a range of RF relays such as the Nedis RF range.

These are super useful for controlling lights with a wireless switch or handheld remote control.

However these systems are typically not smart so often don’t have the app and voice control etc.

An exception to this is the Lightwave system which features a single and a triple channel relay which is smart, can be controlled by smartphone, voice control and even Apple Homekit.

You can also wirelessly link the relay channel to a physical Lightwave wall switch allowing you to seamlessly control the relays from the wall.


You should now have a better understanding of what smart relay modules are and where you’d use them.

If you need any help choosing the right relays for your smart home then please feel free to contact our expert team by email, live chat or calling on 02392 006118.

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