Two wire Thermostat for Fireplace

I need to replace the existing thermostat for my Gas Fireplace. Turns out there are only 2 wires connected the this device (W and RH). The fan is controlled internally within the fireplace itsself so I dont need to worry about it.

What thermostat compatible with ST can I use that only requires 2 wires, uses batteries or can be wires to an 12/24v a/c adapter?

Hi @cdikland, I personnaly use the CT-30 thermostat for my fireplace:

It can be powered by batteries and it’s not too expensive (especially on ebay)… The only drawback is that the batteries last few months (3 to 6 months according to your usage).

There is newer version of it (CT-100), but I don’t know if it uses less batteries than the CT-30…


I have a two-wire gas wall heater that functions the same as a two-wire fireplace. I use the CT-101 from Lowes. This thermostat works great for me! I’ve replaced the batteries twice in the last 14 months, and the current batteries are at 40%.