I am in the process of replacing a millivolt thermostat that controls my Regency Fireplace insert. Coming off the insert are two wires that when connected together open the gas valve and the fireplace insert begins operation.

I purchased a new thermostat that allows me to call the thermostat via telephone to adjust the temperature of the room. Unfortunately, this is a 24v thermostat. When I called the vendor, they suggested I get a 24v transformer and a relay.

I suspect that I need to connect the two wires from the insert to the NO and C terminals on the output of the relay. What should my input side look like?

I think... one wire from the 24v transformer will go to the R connection of the t-stat, the other wire will go to common on the relay, which somehow goes to common on the t-stat. The W wire will go to the relay so when the t-stat engages, power will flow through W to the relay, causing the magnet to close NO and thus igniting the fire place.

Does this sound right? What am I missng? What type of relay do I need?