I have a continental gas fireplace, and the wires from the thermostat to the fireplace have come disconnected at the fireplace. There are four wires: yellow, red, green, and black. There are three vertical terminal posts labeled from top to bottom TP TH, TP, and TH. Can you tell me which wires go where? Thanks.
Gary, my rule of thumb when it comes to anything in a home involving gas is better safe than sorry. That's why I usually recommend getting an expert involved when hooking up a gas appliance, even if it's just wiring up a fireplace thermostat. However, a homeowner with average DIY skills and the documents that came with the fireplace should be able to do the low-voltage wiring for a thermostat.
Your fireplace should have come with an instruction/installation manual. If you purchased the home new with the fireplace installed, the manual may be in with the other appliance paperwork provided by the builder. However, if you aren't the first owner of the home and weren't provided the booklet by the previous owner, it's possible you may be able to go online to the fireplace manufacturer's website and download a manual there.
The manual should describe exactly how the thermostat is to be wired. This type of wiring is low voltage so as long as the wires are on the correct terminals and there aren't any bare wires touching, the thermostat should work properly. However, if you question at all your ability to do the job properly or there isn't a wiring description in the manual, I highly recommend calling in a fireplace contractor to do the hook up. The company that did the original installation would be the best option, but if you don't have that information, just about any fireplace contractor should be able to wire the thermostat.