Is there a special wall switch for fireplaces?

April 8, 2022 2:27 PM

I want to replace the wall switch that controls our gas fireplace, but I have questions.

I want to replace the old-style toggle wall switch that turns our gas fireplace on and off. At a minimum, I'd like to replace it with a rocker switch, but ideally I'd like to replace it with a smart switch that works with the Google Home ecosystem*.

I know this is a naive thing to say, but the existing switch looks like a normal light switch; everything I read about replacing these switches, though, seems to indicate that it may be a "millivolt" switch, which works on/with lower power than a regular one.

I guess these are my questions:

- Is there any way to tell by looking (when I take off the wall plate and pull the existing switch) whether the existing switch is a millivolt switch, so I know what kind of replacement to buy, or is it safe to assume the existing switch is one?
- If I shut off power to the room that contains the fireplace in order to make the change, do I also need to shut off the gas/pilot light in the fireplace itself?
- Is it even possible/desirable to connect a gas fireplace to a smart switch (I'm fine paying someone to do this if it's more complex than just "take out old switch, put in smart switch")?

*I will say that "Connect gas fireplace to smart switch" probably is the least important part of all this, and I could easily live with it being connected to a traditional switch; I just figure since I'm wanting to make a change in switch anyway, I'd see what it looked like to change to a smart switch.

posted by pdb to Home & Garden (4 answers total)

You also have the option of placing something like this Swicthbot rocker switch smart control over the existing switch.
posted by DirtyOldTown at 2:41 PM on April 8, 2022

The main issue is that if the circuit needs a millivolt switch, and you use a 120V switch, it'll probably stop working in a few years due to oxidation. However, nothing else bad will happen. The voltage is too low to be any kind of hazard.

When the switch we had in our new-built house stopped working after a four years, it was obvious that the builder had just used a regular 120V switch. After investigating the pricing on millivolt switches ($20, vs $2 for a 120V switch) I replaced it with another 120V switch, plus nine spares for the same price.

So I'd go ahead and use the 120V smart switch; the worst case scenario is it'll need to be replaced in a few years.

You don't need to shut off the gas. It won't turn on randomly while you're replacing the switch.

PS -- It's almost certainly a milivolt switch powered by a thermocouple next to the pilot light.
posted by kindall at 3:26 PM on April 8, 2022

I only have smart outlets and not switches, but some of them are too deep to install in a standard sized new work electrical box if that's what you have for the existing switch. That might be something to investigate before purchasing a new smart switch.
posted by sevenless at 3:47 PM on April 8, 2022

If the "smart switch" is not 100% battery powered, it's not going to work when connected to a millivolt circuit. My experience is more with electronic timers than smart switches per se, but many electronic timers are expecting to "steal" 120V power to run their internal electronics.
posted by Larry David Syndrome at 4:01 PM on April 8, 2022 [4 favorites]