Features Large, backlit digital display Accurate temperature control of +/-1 degree Fahrenheit for consistent comfort. Set point is retained in memory in the event of a power outage. Soft-touch keys. Easy operation. Easy to install. Battery operated. Easy access battery replacement. Compatibility Chart 24 - Volt Heating and Air Conditioning Systems: Compatibility Single Stage Heating and Cooling Yes Multistage Heating and Cooling Yes Heating Only Yes Cooling Only Yes Furnace (Warm Air) Yes Central Air Conditioning Yes Heat pump without Auxiliary Heat Yes Heat pump with Auxiliary Heat No Hot Water Yes Steam or Gravity Yes 750 Millivolt Yes Gas Fireplaces Yes Electric Baseboard Heat No