Line Voltage Or Low Voltage: What Thermostat Do You Need?
The back of a Honeywell low-voltage thermostat, left, and a Cadet line voltage thermostat.Take note of the different size of wires between the two types of thermostats. Line-voltage thermostats have much thicker wires.
Line voltage thermostats
Line voltage thermostats are typically used for radiant, convection or resistance heaters that are powered by electricity. They are the type of thermostats to use with our baseboard and wall heaters. Also, you will use a line voltage stat for cove heaters and in-ceiling radiant heat. If you are replacing a thermostat in your home, one of the best ways to find out which one you need is to check your wiring. Line-voltage units have two or four thick wires coming out of the back that are attached with wire nuts to wires in the wall. (Sometimes the thermostats are attached to the heater themselves.)
Low voltage thermostats
Low voltage thermostats are more common. These thermostats are used with central heating systems including furnaces, boilers, air conditioning, heat pumps and split systems. The giveaway for these types of thermostats is that they have multiple wires going into them and the wires aren't as thick as you would find on line-voltage (← Is line voltage two words or hyphenated word? Which ever it is, we need to keep consistent in the article) stats.
A quick recap ,if you are looking for a thermostat: if you are using a Cadet or other radiant heater in your home, you will need a line voltage thermostat. If you are using a central system, you will want a low voltage thermostat. And, if you have both your home; There is no rule against using baseboard or wall heaters to complement a central system by warming up a in a cold room or basement, then both it is.