Fireplaces are a bit different. What you want to do is use a HAI relay output to turn on a 12V output and run that to the fireplace, the get a 12V relay and use the contacts to connect to the fireplace. DON'T run long wires from the fireplace and expect the HAI relay to control it directly. Not safe.
I don't understand this. Downstairs, my panel is 3 wire-feet from the wall switch, and the wall switch is 10 wire-feet from the fireplace. Upstairs, the electricians ran the wire a good 15' to an identical switch and fireplace. But you claim I cannot have the 12V relay at the panel. Should it be at the switch or the fireplace? If it's in the fireplace, where do I get a 230 degree-rated relay: everything in there must be high-temperature rated; even the romex.
Chris D.
Your fireplace uses a thermocouple to generate a really small amount of electricity which your fireplace uses to control the fireplace. That is why it has a switch, but yet no electrical power. The normal solution you'd think you could use would be to tap the two wires from the switch (and I'm guessing its in the wall next to the fireplace) and run that to a set of contacts on the HAI panel. BUT you don't want the low-voltage fireplace wires to run a long distance, rather, you want the relay contacts controlling the fireplace to be as close to the switch as possible. In the box with the switch is ideal, but not in the fireplace, as you would need a high-temp relay, as you say.
So, you know you home's layout better than us, but one solution, if you panel is a ways from the fireplace switch is to put the relay in the box with the fireplace switch. Note that the fireplace switch is not 120V, so you can mix a low voltage relay and a fireplace switch in the same box and not violate codes.
So you want to use an HAI output to control a relay in your panel, and have the relay contacts on that relay control a second relay in or very near the fireplace switch. This seems like a bit of overkill, but it isn't. First, the HAI outputs are susceptible to static and noise problems, so you always want the outputs to control relays in the panel, and not run long distances outside the panel. On the other end, the fireplace switch shouldn't be extended long distances for the same reason. Besides, relays are cheap. Radio Shack or Fry's Electronics carries them.
If you haven't already, Install HAI's 4 or 8 bank of relays in the panel and wire each HAI output to each relay. In the fireplace switch you want to install a relay like this:
Radio Shack Reed Relay These are great because they are cheap, reliable and small. Last, use 12V from the panel, switched by a panel relay, to control the reed relay in the fireplace switch.
You could also use the SAUMI32W (Simply Automated I/O box) which contains a relay, to also control the fireplace, but while UPB is reliable, I myself still wouldn't trust it to control a fireplace, but that's your call. I actually control two pool pumps with this I/O module (and a big relay) and it works great. I'd use an HAI output if I could, but this distance is too great.
