Why do I have 6 wires for my thermostat?
If your system has six wires, it’s because it features second-stage heating, second-stage cooling or heat-pump cooling but not all three. The extra wire signals the additional function to come on. If your system has second-stage heating and cooling as well as a heat pump, then the thermostat needs eight wires, not six.
How many wires does an HVAC thermostat have?
4 Wire
4 Wire Thermostat Wiring (Heat Pumps, HVAC) Smart thermostats like Nest and Ecobee thermostats require 4 wire thermostat wiring to function properly. In addition to heating (2 wire thermostats) and C or fan (3 wire thermostats), 4 wire thermostats include the cooling wire, usually in blue or yellow color.
What is W2 wire on thermostat?
W2 – This is the thermostat terminal used for second stage heat. There are gas furnaces with low fire and high fire and some depend on control from a two-stage heating thermostat with a W2 terminal. Heat Pumps use staging for auxiliary heat and need a W2 terminal.
How many wires connect to a thermostat?
Note on Thermostat Wiring for Communicating HVAC Systems Communicating systems use only 4 wires. However, the basic wiring principle is the same: Each wire must connect to the furnace or air handler terminal and the corresponding thermostat terminal.
What is AC wire for a thermostat?
What is the C Wire on a Thermostat? The c wire is an extra wire that can be used to provide a return path for continuous 24V power for any application. It’s normally used to provide a return path to power the thermostat. The “c” stands for common.
Can I install a new thermostat without shutting off power?
The short answer is no, it’s not OK – you increased your risk of electrocution and that’s never a good thing specially for a DIYer. Now that being said, everything is working and you didn’t burn down your house, so you got off OK, but generally speaking, this was a bad idea.
