I have a natural gas fireplace with a standing pilot and a thermopile in series with a normal SPST 120 volt switch. It uses a Honeywell VS8421 gas valve. I believe that closing the switch allows current to flow to open the gas valve and the pilot then ignites the gas. I want to be able to use an electronic setback thermostat to ignite and turn off the gas burner at given times. It seems to me that I should just be able to take the wires that are currently attached to the SPST switch and attach them to the RH and W terminals of an extra setback thermostat I have. When the thermostat calls for heat it will close the circuit and ignite the burner. When the set point has been reached, it will open the circuit and cut off the gas. In other words, it will function just as the SPST switch, but I will be able to control it by time and temperature. I believe that VS8421 operates on a low enough voltage that this should not be a problem. Any opinions?