Heating thermostats and controls for line-voltage and low-voltage systems: Cadet single and double pole line-voltage baseboard and wall-mount thermostats; Honeywell Home dial, lever, push-button and programmable models including the X1N, X2P, X2S and X8S, plus a lever thermostat guard box; White Rodgers and Mr. Heater dial and push-button units; and Ecobee, Sensi and Copeland Sensi Wi-Fi thermostats. Line voltage and low voltage are not interchangeable and this is the mistake to avoid — a baseboard or resistance heater switches the full 120 or 240 V load and needs a line-voltage thermostat, while a furnace or heat pump is controlled by a 24 V low-voltage stat. Single pole leaves one leg energized at the off position; double pole breaks both and is what you want where the circuit needs to be fully dead at the thermostat. Smart thermostats need a common wire on most systems, so check the wiring at the existing stat before ordering one.
