View Full Version : wiring two switches for a gas fireplace
12-07-2008, 06:07 PM
I just installed a gas fireplace. My hope is to be able to have 2 separate locations for on/off switching as far as the pilot/starter, essentially just a three-way circuit, except that the unit doesn't seem to be wired for that sort of situation. Inside the unit is a complex wiring harness, but the connection for the low-voltage is simple enough. As a trial I connected a 50 foot run of 14G 3-wire to the harness and there's no problem turning it on or off. I'm just not sure how I can connect another switch for a different location. The only wires coming off the harness are a white and a red - the unit came with a ten foot strand of 16 or 18G (something really fragile) wire already connected to the harness, so I just clipped them and connected the 14G, thinking a thicker wire might allow for a longer run and less voltage drop.
Unlike a typical 3-way circuit, the fireplace unit has a separate 110 connection that doesn't seem to have any way of connecting through the 3-way switches.
Any help or insight appreciated.
12-07-2008, 06:29 PM
Those fireplaces do not use 120v for the control. They use a millivolt control off a thermocouple off the gas valve. You do not need (or want) #14 wiring for this. You will regret it and I would not want to stress the terminals with such big wire. You can/should use 18/2 thermostat wire.
You can wire the two switches in parallel so that either switch will turn on the valve. Thing is both switches will have to be off for it to be off. I can't see this as a problem though.
The 120v receptacle (if it is even wired) in the unit is for an optional blower unit.
12-07-2008, 07:06 PM
speedy petey -
Thanks. So there's truly no way to have 2 fully separate switches for this thing? I was hoping to have something at the unit and another at the entrance to the room.
Also, is it then the case that I will need to periodically detach the face of the unit and replace the 2 D batteries?
12-07-2008, 07:29 PM
Certainly there's a way to hook up two switches so either one will turn it on or off. the logic is the same as a 3-way light circuit.
12-07-2008, 07:33 PM
Like Jim says, you sure can wire it like a typical 3-way if you want to.
12-07-2008, 07:46 PM
Just use two 3-way switches which work like this...
(And of course you would not be connecting this to house power or a light, but to your fireplace wiring instead.)
12-07-2008, 07:48 PM
It's heartening to hear I may not be out of options.
However, the times I've wired three or four way circuits, I typically have one end of the circuit on the load and the other connected to the power and the traveler wires between. In this case, with only two available wires to connect off of, I'm not getting where the specific wires would attach between the switches.
As an example, I took a few feet of my 14/3 and connected the red and white to the red and white in the firebox and then connected the red and white on the other end to a 3 way switch, worked perfectly. I took another three way switch and tried to connect it to the first switch with another run of wire, but I can't sort out the specific wire attachments for them to work independently.
12-07-2008, 08:00 PM
Thanks. But in this scenario, the 2 D batteries (i.e. the Power Supply in your schematic) are wired into the harness somehow, which then spits out the red and white wires that I'm connected to, and from there I'm wiring the two 3-way switches in sequence and trying to connect the wires so they work independently. I may be missing something simple here, but it almost sounds as though I should detach the D batteries and use them at the start of my switching run, if that makes sense.
12-08-2008, 06:41 AM
The only wires coming off the harness are a white and a red - the unit came with a ten foot strand of 16 or 18G (something really fragile) wire already connected to the harness, so I just clipped them and connected the 14G, thinking a thicker wire might allow for a longer run and less voltage drop.
On the back of the three way switches is the word “common”
This screw will get one of the wires coming from harness (the red and white). In other words one switch will get the red and the other switch will get the white. It doesn’t matter which switch gets which wire (the red and white)
When you come into the first switch box with the conductors from the harness take one of the conductors from the harness and connect it to the common screw of that switch. Connect the other conductor to one of the conductors of the three conductor and send it down to the other switch (the conductor you choose is up to you) and land it on the common screw of that switch.
Now there will be two conductors left in each box. These will go on the two screws left on each switch and it doesn’t matter which one goes on which screw.
12-08-2008, 07:52 AM
jw - thank-you. I will try this tonight.
12-08-2008, 08:56 AM
If you could post pictures of all the wiring in the gas fireplace, that would help.
If you could say the exact brand and model of the fireplace, that would help.
Then if you could draw a diagram of where you want to place the two switches in your living room, then we could describe to you what would need to be done with the wiring.
If you could take pictures or the walls or where the switches will go, then we might have suggestions on how to run the wires.
12-11-2008, 12:48 PM
I got it working - thank-you all for your help. Wouldn't have thought it possible otherwise.