I've been progressively going through my house changing all of the light switches to smart switches, primarily the TP-Link HS200. I have a light switch that controls a fireplace, and it's different from the other switches I've replaced in two ways.

The first is that it seems to always have power. I have tried every circuit and even turning it off at the main and my voltage detector still goes crazy near the switch's wires. It stops working when I flip off the circuit. It can have battery power as a backup, but I haven't put any in.

The second is that there is no neutral wire.

Is there a way for me to make it to I can make the fireplace smart without running a neutral wire? I don't need it to be the switch itself (although if people are going to suggest a relay or something else that's not a switch, I'd like to confirm that I can still exchange the switch for a standard single-pole paddle switch).

Ideally, a solution would meet the following criteria:

• Works with Google Home
• Doesn't require Z-Wave or Zigbee or anything else beyond Wi-Fi.
• Doesn't require batteries or new wiring behind the wall
• Can be done for less than $50.

If I can't do something matching the above, is there any way that the way it's currently wired is a code violation? It's a new house so I could make them fix it if it was. I don't think so, since everything I can find on the subject relates to switches with lighting loads, but I'm not an electrician, so I figured I'd throw it out there. I live in Apex, NC.

 

Can you post the make and model of that fireplace ?
Typically those switches only control low voltage to the fireplace. If you look at the two tags on where those wires connect is says to NOT connect them to 110VAC.

I'm fairly certain you could put a smart type device inside the unit but doubtful in the wall switch location. I look forward to the info on that unit.

 

Based on the manual that was left for me, it is one of the following Hearth & Home models:
DV3732-B
DV3732L-B
DV4236-B

If you need the exact model, let me know and I will start looking for one on the unit itself.

Thanks!

 

Here is the manual. Wiring info begins on page 41.
https://downloads.hearthnhome.com/in...s/2355_980.pdf

That wall switch operates at 3 volts. There is a battery pack inside the unit also. It takes 2 D cells.
There is also a remote option available.

 

I'm probably missing the obvious, but I'm not seeing how I get the fireplace connected to Google Home.

 

NOt knowing anything about google home my guess would be you can't with what you have. Google home operates at 120 volts. That switch operates at 3 volts DC.

 

Sorry, I may have been unclear. I was referring to the Google Home smart home ecosystem, which doesn't have an inherent voltage, as opposed to the specific device. As an example, my Ring Doorbell works with my Google Home devices, even though it is much lower than 120 volts. I'll be shocked if there isn't some kind of relay or something that can be operated with a Google Home, I just have no idea what that would be or how I would connect it into my fireplace.

 

Do they make a thermostat for that system? That might work.

 

Something like this might work.
https://www.bestbuy.com/site/insigni...?skuId=5933701

You need a switch with a relay that you can turn on/off. The garage door controller might work, but it might only provide a brief 'on', followed by switching off.

I like joed's suggestion though. A compatible thermostat could work since it's really just a relay that turns on/off the furnace. Ignore all the temperature settings and such, and just use the controller to turn on/off the heat/fireplace.

 

There are plenty of wifi relay modules that work with google home, but for some reason it is hard to find one in a box.
Basically you need a relay switch with latching capability.

Most of the modules I found requires external DC power supply.

https://www.amazon.com/Sonoff-Wirele.../dp/B07F6YZXST
https://www.amazon.com/MHCOZY-Wirele...JYTK8NF21GRXNC
This one is bit over kill, but looks nice. 4 channels, although you will only use one. Also, you don't need external power supply as it can take AC input.
https://www.amazon.com/Sonoff-4CH-Pr...rds=sonoff+4ch

Another option you have is just use regular AC smart power switch and add a relay with 120V coil.
Have smart switch switch relay on and then the relay will switch low voltage line.

Some garage door openers have a option for latching, but most are momentary only.
The on Zorfdt suggested won't as it is momentary only.

You could modify some regular smart switch to make it low voltage since you just have to modify relay wiring inside, but I wouldn't recommend it unless you are good with electronic circuits.
Also, it won't have required isolation between line voltage and low voltage circuits.

 

You can use ANY good grade switch as a replacement for the one that is there.
Any battery operated thermostat will work there.
No smart switch will work in place of the wall switch at that location.

The two modules listed by Lambition in post 10 are absolutely perfect for that application. The fact that they are low voltage makes them even better. You use one of them and a plug in 12vdc wall transformer. Both will be under the fireplace. Only two wires from the module to the fireplace.

Amazon Sonoff switch
12vdc wall adapter

 

Actually both modules I listed uses 5V micro USB power and probably better option. Readily available to use as cell phone chargers.
The first one can also take 7V to 32V on screw terminal because it also has regulator circuit.
The second one can only take 5V on both micro USB or screw terminal.

 

Thanks everyone. So I can just order the module PJmax linked to and use a USB adapter?

Could someone tell me what wires I'd need to plug into the module? Do I need to order any wires separately?

Also, will it be possible for me to turn on the fireplace using either the wall switch or the module or will the module essentially replace the wall switch?

 

Yes.

You may need a short length of wire if you don't already have. 18 or even 24 AWG wire will do. Thermostat wire, bell wire, phone wire, CAT5, speaker wire.. any of these wires will work for this purpose.

Just connect wires going to existing switch between common and normally open terminal.

If you just wire it parallel, it will work with both. However, you cannot turn off remotely if you turn on the fireplace with switch.
It is also possible to add a external momentary switch to turn it on/off manually, but you will have to solder wires directly to the switch on the PCB because terminal is not provided.

Also, you will have to mount or enclose this module so that back of this module does not short out.


Sonoff 4CH Pro will be more convenient to install if you don't mind higher price.
With this module, you can wire AC power straight to AC input terminal (a 2 wire cord will be needed) or use external DC power supply between 5V and 24V with barrel connector.
You will also have better support from the manufacture.

One additional feature I find with this is you can pair it with 433MHz remote controller as well. This could be more convenient then wall switch for local use.
https://www.banggood.com/433MHZ-Remo..._warehouse=USA

 

Thanks everyone for all of your help! It took me a while to get the item, since it was shipping from China, but it made it here and I finally had a chance to install it this weekend. It's working great.

 

Which module did you end up using?

 

This one. While it was more effort, it actually ended up cheaper than using the smart switch I was planning on using.

 

A very cost effective solution.