1) Yes. 2) Yes.

This unit will go down to 4.5 C

You can go to their website and follow this link:

http://yourhome.honeywell.com/home/products/thermostats/

I have a 2 wire system (One white wire and one black) and I installed it and it works great. Very happy with this unit.

Electric baseboard: no (because these run 120/240 volts AC)
Low-volt Hydronic baseboard: yes (because these run 24 volts AC)

If you're unsure what type of furnace system you have, read descriptions below:

Type of Heating or Cooling System: Millivoltage – Gas Furnace System
The Number of Wires to the Thermostat: 2
Voltage: 750mV
System Attributes: Top or Direct vent wall furnace for the smaller rooms/areas; Gravity wall (room) furnace; direct vent wall furnace – mobile homes

————————————————–

Type of Heating or Cooling System: Standing Pilot (continuous flame, 24 hour) – Gas Furnace System
The Number of Wires to the Thermostat: 2 or 3…or 4 to 5 with air conditioning
Voltage: 24 Volts AC
System Attributes: Forced Air Furnace & Standing pilot. A forced air furnace is absolutely the most common type of home heating and air system (HVAC). In a forced air furnace, the air is heated in the furnace by burners fueled by natural gas, oil, propane or electricity. The heated air is then circulated throughout the house through a system of ducts and into the various rooms through registers.

————————————————–

Type of Heating or Cooling System: Electronic Ignition (i.e. Intermittent Pilot or Hot Surface Ignition) – Gas Furnace System
The Number of Wires to the Thermostat: 2 or 3…or 4 to 5 with air conditioning
Voltage: 24 Volts AC
System Attributes: Forced Air Furnace, Intermittent Pilot or Hot Surface Ignition.

————————————————–

Type of Heating or Cooling System: Low Voltage – Gas Fired Boiler System. A boiler is a heating device used to create hot water or stem for a steam radiator, hydronic baseboard, or radiant heat heating systems. Hot water boilers are compact, low maintenance and energy efficient. Steam boilers are more complex than standard hot water boilers as they use pressure gauges, blow-off valves, special gauge glass and automatic feeds. As a whole, boilers use a variety of fuels for power including electricity, propane, natural gas or oil.
The Number of Wires to the Thermostat: 2 or 3
Voltage: 24 Volts AC
System Attributes: Hot water boiler for or radiant heat systems or baseboard hydronic systems. A radiant heat system has the reputation of providing the most comfortable heat in a home. The heat is generated through a process of radiation or direct transfer from a hot to cold surface. This heat is generated through a variety of different methods, often including in-floor hot water tubing. A hot water baseboard system uses hot water to heat an area/room through a combination of convection and radiation. It is very similar to radiant heat, but the hot water baseboard system always uses hot water which is heated by a boiler.

————————————————–

Type of Heating or Cooling System: High Voltage or Low Voltage – Oil Fired Boiler System
The Number of Wires to the Thermostat: 2 or 3
Voltage: 120 Volts AC or 24 Volts AC
System Attributes: A hot water boiler is used for a baseboard hydronic system or radiant heat system.

————————————————–

Type of Heating or Cooling System: Low Voltage – Electric Boiler System
The Number of Wires to the Thermostat: 2 or 3
Voltage: 24 Volts AC
System Attributes: A hot water boiler is used for a baseboard hydronic system or radiant heat system.

————————————————–

Type of Heating or Cooling System: Low Voltage – Oil Fired Furnace System
The Number of Wires to the Thermostat: 2…or 4 to 5 with air conditioning
Voltage: 24 Volts AC
System Attributes: Forced air furnace. As mentioned previously, the forced air furnace is the most common type of home heating and air system (HVAC) in use today.

————————————————–

Type of Heating or Cooling System: Electric Furnace
The Number of Wires to the Thermostat: 2…or 4 to 5 with air conditioning
Voltage: 24 Volts AC
System Attributes: Forced air furnace

————————————————–

Type of Heating or Cooling System: Electric Air Conditioning
The Number of Wires to the Thermostat: 4 or 5
Voltage: 24 Volts AC
System Attributes: The condensing unit is located outside the home with cooling coils in the furnace ductwork.

————————————————–

Type of Heating or Cooling System: Electric Baseboard Heat
The Number of Wires to the Thermostat: 2 or 4
Voltage: 240 Volts AC or 120 Volts AC
System Attributes: A line voltage thermostat is located in every room to provide localized heating.

————————————————–

Type of Heating or Cooling System: Heat Pump – single stage
The Number of Wires to the Thermostat: 4 or 5
Voltage: 24 Volt AC
System Attributes: Heating and Cooling is provided through use of an outdoor heat pump.

————————————————–

Type of Heating or Cooling System: Heat Pump – Multi-Stage
The Number of Wires to the Thermostat: 7 or more
Voltage: 24 Volt AC
System Attributes: Heating and Cooling is provided through use of an outdoor heat pump.

Put your index fingure on the right hand side of thermostat and push down and outwards. The battery case will pop out.