What is the 4 wire on a thermostat?
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. Here are the wires in 4 wire thermostats with terminal codes and color codes: Red wire for power (24V). White wire for heating (connected to W or W1 terminal).
What are the color codes for thermostat wiring?
Here is the industry standard thermostat wire color code used for most systems:
- White. The white wire connects to your heat.
- Yellow. The yellow wire connects to your compressor.
- Green. The green wire connects to the fan.
- Orange. This wire connects to your heat pump (if applicable).
- Red (C).
- Red (H).
- Blue.
Are thermostat wires color coded?
The thermostat wire is color coded so the technician can identity which wire goes to which port on each board. It’s important to note that in some cases the color of the wire does not necessarily mean it connects to that came color one the board.
What color is ob wire?
Orange
Thermostat Wiring Color Code Chart
| Marking | Wire Color Code | Description |
|---|---|---|
| O | Orange | Change-over relay to cool relay |
| B | Blue | Change-over relay to heat relay |
| A | Heat and cool active to any relay | |
| L | Emergency heat active lamp |
What color is the common wire in a thermostat?
The common wire is usually blue or black, but that is not guaranteed. The previous homeowner may have made the wires whatever color they wanted or they could have run any wire they had available, so never rely on color alone. Regardless of color, the common wire is connected to the C port inside your thermostat.
What color wires go where on a thermostat?
Thermostat Wire. Thermostat wire comes in a bundle with the outer jacket of the thermostat wire being either brown or white. The bundle can have anywhere from 2 conductors inside the bundle or outer jacket and all the way up 8 or 10 conductors inside the outer brown or white jacket.
How do you wire a thermostat?
Twist the wires to the connectors on the back of the thermostat or follow the directions provided with the manufacturer’s instructions. Attach the thermostat face to the new wall plate. Push all wires back into the wall, and slide the plate onto the wall plate.
What do thermostat wiring colors mean?
So, this is what you might expect to see in terms of colored wires and what they mean: White – The white wire is what connects to the (auxiliary) heat on your system. Yellow – The yellow wire connects to your compressor. Green – The green wire connects to the fan. Orange – This wire connects to your heat pump (if you have one). Red – Now, there can be two separate wires for this. Blue – This is your common or “C” wire.