Multiple Lights on double gang switch

Seems like this would have been a topic, but the suggestion pop-up didn’t address it. Situation is as follows:
Single gang switch box with a double gang switch, i.e. two SPST in a single gang form factor. They obviously control two different lighting circuits in the same room. Each lighting circuit has multiple bulbs at the fixture. Smart bulbs and the use of a scene seems absurd. The cost would be ginormous and bulbs burn out eventually. So, the solution needs to be a single node control for each circuit. Problem is the switch box size. My intuition says to make this easy by breaching the wall and simply putting in a double gang box. I’m wondering if any one has thought about creative solutions to this scenario? I’m a newbie in the z wave world and don’t really have the products memorized yet. I would also like to, if possible, stay with latest generation products, and at the least be all Plus enabled. Thoughts? Thank you in advance.

Search dual relay.

:sunglasses: Leviton VRCS2. Very popular in the community for just this purpose, particularly for bathrooms where one toggle controls the light and the other toggle controls the small exhaust fan. You’ll need the custom device type handler to make it work with SmartThings.

That said, Leviton is in the process of replacing most of its line with new Z wave plus versions, so this particular one may be a little difficult to find and the new one isn’t out yet.


Lots of food for thought now that I know dual relays exist. A gripe I’ve had on duplex receptacles was that they only controlled half of the receptacle. Seems like the dual relay technique could be used for such an application. Anyone doing that?

With regard to where I bury these units, it just occurred to me that with my entire house being EMT, the z wave could be severely limited. I understand the nature of the mesh network, but still, if every device has its signal strength severely attenuated I might need to have a fairly dense network to overcome it. Didn’t see any subjects pop when searching for attenuation. I haven’t installed any duplex receptacles yet due to the aforementioned annoyance and not having found a Plus version yet (GE/Jasco).

Thank you all for the prior replies.

When you say your entire house is EMT, do you mean the conduits are all thin wall sheeting?

Z wave and zigbee are both wireless radio frequency protocols, so, yeah, if you’re putting the relays inside the tubes you may have a problem. That’s not usually an issue if you’re at a breakpoint like the lighting fixture or the switchbox. And that’s where these devices are usually put just because it’s easier access. I think it’s just going to be a matter of finding the right place to put the relays if that’s how you go. There are people successfully using Z wave light switches in concrete or adobe houses where there’s almost 100% attenuation through the wall material itself.

@Navat604 are one of the other electrical experts in the community might have more to say.

If you use an actual integrated switch device like the Leviton, then there shouldn’t be any problem with getting signal out to the room.

Hi, like you I am fairly new to SmartThings and I have been trying out different Things. In my kitchen I have two light fittings each with three GU10 LED lamps. The fittings are on different circuits, both circuits are controlled from one single gang faceplate with two toggle switches.

I have just installed a Fibaro 2 x 1.5kW relay to allow me to control both circuits independently. I had to replace the existing 35mm single gang back box with a 47mm one which meant making the hole in the wall deeper.

Once installed the switch paired with SmartThings and I could control circuit 1 from the app. To control the we one circuit I had to install the ‘z-wave multichannel device smart app’ (I also tried custom code but this didn’t provide me with the ability to include both circuits in automated routines so I stuck with the smart app). I can now control both light either through SmartThings or using the switches and unlike my Hue lamps in other rooms it doesn’t matter if the switches are off or on, the app can still control the lamps.

The device is available on Amazon or Vesternet. https:///Fibaro-FGS-222-Dual-Relay-Switch/dp/B00WH0S8F0

The device does need a neutral wire in the switch back of to supply power, if you don’t have this you will need to use the Fibaro dimmer 2 which can still be used for on/off control but doesn’t require a neutral. Aeon aslo make similar products that I would consider trying.

Since your conduits are EMT so most likely your gangboxes will also be metals. I suggest you get the Emerwave Z-wave plus dual relay module. You have a little of a leeway with the placement of the antenna with most of these in wall micro relay module because the antenna is flexible but to be safe go with z-wave plus. It has longer range.


Yes to the question of all metal. In my area, code will not allow for metal tubing and plastic junction/termination boxes. I can of course do that on the sly if need be. The definitive answers would seem to revolve around the ability to accurately measure signal strength at each node. Since the boxes are almost faraday cages except for the one exposed side, it all depends on which way they are facing with respect to my primary. Primary is in my equipment room with all the other electrical stuff/computers and is centrally located in the house. As you say, judiciously positioned repeaters could alleviate the issue. Thanks again for the good conversation.