5-1-1 Day Programmable Thermostats for Home 1 Heat/ 1 Cool Conventional Single-Stage Systems. It is advisable to proceed with caution if you do not have prior installation experience to prevent issues such as malfunction and incompatibility due to purchg the wrong item. (Verify the existing base to ensure only 2 to 5 wires are compatible for installation and wiring). Compatible Systems? Single-Stage Heating & Cooling, Boiler Radiant Heating Only, Furnace Forced-Air Heating Only, Cooling Only, Gas Fireplace (24 Volts), 750 Millivolt, Hot Water Steam or Gravity Radiant Heat. Incompatible Systems? Does not work Multistage Heating & Cooling, Heat Pump with Auxiliary Heating, Heat Pump with Emergency Heating, Dual Fuel/Hybrid Heating, Mini Split Systems, Electric Baseboard Heat (120-240 Volts), Convectors, Radiant Ceiling Heat, 12v RV Thermostat. S705 5-1-1 day programmable thermostat 1 Heat/ 1 Cool. Separate programs for the weekdays and weekends with 4 program periods per day including wake, leave, return and sleep. Digital thermostat has a built-in battery change and filter change reminders (Set 50-2000 hours)? Room temperature calibration adjustment? Accurate temperature control of +/-1-degree F for consistent comfort, (Room temperature display range: 41°F to 95°F, Temperature control range: 44°F to 90°F)? Easy-to see and read? Display with blue backlight, large clear backlit digital display, very suitable for middle-aged and elderly people.