If any wires were not originally connected to your current thermostat (and don’t have a label), they typically aren’t connected to your system. Do not connect these wires to your current thermostat or Nest thermostat. Wires labeled B typically should go into a Nest thermostat’s O/B connector.
Is B wire same as C wire?
The common wire, usually labeled C, should go in the C Terminal of the Zen Thermostat. A wire labeled O, B, or O/B is used to control whether a heat pump is in heating or cooling mode. However, on some thermostats, a wire labeled B is the common wire C. In most cases, the common wire is labeled C.
What is B on Honeywell thermostat?
O, B, O/B: These wires are responsible for switching the changeover valve in a heat pump system. The O wire reverses the valve from heating to cooling, and the B wire switches the valve from cooling to heating.
What is the B terminal on a thermostat for?
W/B: The W/B terminal controls the heat relay or valve. When the thermostat calls for heat, a signal is sent to power up the furnace and the blower fan or the boiler, heating your home.
What is the white wire on my thermostat?
The white wire underneath your thermostat connects to your heating system. It terminates at your air handler or furnace. The white wire connects to terminal W in industry-standard thermostats.
What do the different color wires mean on a thermostat?
This is the most typical thermostat wiring style, and it applies to systems that regulate both heat and air conditioning. The wires are typically arranged as follows: red for 24-volt hot, white for heat, yellow for cooling, green for the fan, and blue for common (although the common wire may be a different color).
What color is C wire on thermostat?
Blue wires are also called “C” wires because they are the Common wire. C wires are necessary for any “smart” thermostat that needs to be connected to a power source 24/7, regardless of your heat pump type.
What is the yellow wire on my thermostat?
If your thermostat controls your heat, you will have a white wire. The Y wire is yellow and connects to your air conditioning compressor. The G wire is green and connects to the fan.
What happens if you wire a thermostat wrong?
Potential consequences of improper installation could include: Electric shock. Blowing a circuit breaker. Damaging the thermostat unit, the electrical system or even the AC/furnace unit itself.
What is B on Trane thermostat?
B. B heat pump changeover (cool to heat, powered in heat mode) In thermostat applications where a blue wire is used, the blue is usually a common circuit wire – e.g. providing the return path for the circuit. B and O together. Trane heat pump products.
Does Trane energize in O or B?
The heat pump is ‘O’ if it energizes in cooling and ‘B’ if it energizes on heating. Thermostats use the B terminal in systems with a reversing valve that turns on with heat mode. The system uses the O terminal if the reversing valve turns on while running cooling mode.
What is o’b reversing valve?
The O/B terminal is for heat pump systems and is used for the reversing valve. When the “O” option/position is selected the reversing valve defaults to the heating mode. If the “B” option/position is selected the reversing valve defaults to the cooling mode.
Does Trane thermostat have C wire?
The C-wire provides continuous power for your smart thermostat display and WiFi connectivity. Roughly 40% of homes have this fifth C-wire, also called common wire. If you don’t have one or aren’t sure, you should consult an HVAC technician — your local Trane Comfort Specialist™ would be happy to give you a hand.
What color wire goes where on a Honeywell thermostat?
Meaning of Wiring Terminal Letters
W (white) controls the auxiliary heating elements. Y (yellow) controls the compressor on the cooling system. G (green) controls the fan. C (blue or black) provides a return path to the transformer.
Where does the C wire go on a furnace?
On the C-Wire Adapter’s “Equipment” side, connect the wires to the corresponding terminals on the control board. Note: Be sure to remove the plastic tip on each wire before connecting to a terminal. Use the included mount and adhesive pad to attach the C-Wire Adapter inside your furnace or heating system.
What does the RH wire do on a thermostat?
What is the Rh wire on the Nest thermostat? The Rh wire is the power input to the heating system of your air conditioning. If the connection is not established, your air conditioning will stop working.
