Which thermostat models are compatible with 750 millivolt systems such as a fireplace?
Honeywell offers a variety of thermostats that are capable of working with 750 MV heating systems such as fireplaces. Typically these models are battery powered. Thermostats you find at the retail store will indicate on their packaging whether or not it will work with these type of systems. If you've already purchased a thermostat and discarded the package, check the thermostat literature to verify compatibility with millivolt systems.