What is the blue wire on a furnace?
the Common wire
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.
Should blue wire be connected to thermostat?
The Blue or C Wire
C wires or varying colors apply to every thermostat, but blue C wires belong to thermostats attached to a heat pump. Blue wires are for heat pumps. This wire connects to terminal B on your thermostat.
Is blue wire always common?
These wires are also called “C” wires because they’re known as the common wire. This wire allows the thermostat to connect to a power source constantly. Blue “C” wires are most common in thermostats that connect to your heat pump.
How do you run a C wire from furnace to thermostat?
Quote from the video:
Quote from Youtube video: Basically take the the plate here take your transformer. You're gonna make your connections. For everything just like they were on the thermostat that you took off with the exception of two.
What is the blue wire for?
Blue & Yellow
These two colors are hot wires usually pulled in conduit for common plug-in electrical devices. Blue wires are used as travelers, usually on three- or four-way switches (controlling a light from multiple locations) or as switch legs for things such as fans or lights.
What do furnace wire colors mean?
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). You can also refer to the Conductor Color Chart (see Chart 6, thermostat wire).
What is blue wire in old thermostat?
The blue wire, or C-wire, is known as the common wire. It’s there to provide power to the thermostat. Video of the Day. Older thermostats usually don’t have a C-wire because they either don’t need power or, if they do, they get it from a battery. Modern thermostats are a different story.
Where does the blue wire go on my Nest thermostat?
If your thermostat doesn’t have a separate connector labeled C and you’re not sure what type of system you have:
- A brown wire is mostly likely a heat pump wire and should be connected to the O/B connector on the Nest thermostat.
- If the B wire is blue, it should most likely be connected to the C connector.
Which wire is power on thermostat?
A C-wire, or a common wire, runs from your low voltage heating system (24v) and carries continuous power to your thermostat. In today’s electric market, most newer heating and cooling systems have C-wires, which guarantees compatibility for the installation of all smart thermostats.
Can I jump R to C wire?
In the case of Nest and Honeywell (and probably others), their thermostats expect the C wire to come from the cooling system. When you’re connecting the wires to the thermostat in these systems, you’ll have to remove any jumpers between the R terminals.
What if there is no C wire for thermostat?
If your current thermostat didn’t need a C-wire, it (or a wire that can be used as a C-wire) might be rolled up inside the wall. This is more likely to be true if you see all the other color wires present. Line voltage thermsotat scenario: you have just two wires (white and red, probably), and they’re thick.
Where do I connect the C wire on my furnace?
Quote from the video:
Quote from Youtube video: You would typically connect. This a/c wire to be the C terminal on the board on the control board on in the furnace.
Can I connect three wires to the furnace C terminal?
If the terminals are allowed to have more than one wire, it will say so on the terminal block or in the manufacturer’s documentation. Two wires per terminal in HVAC work is common (though not usually correct), while 3 or more will tend to use a pigtail.
What does C wire connect on furnace?
What is a C-Wire? A common wire (C-Wire) provides Wi-Fi thermostats continuous power by connecting it to a heating and cooling system (e.g. furnace). C-Wires are required on most Honeywell Wi-Fi thermostats, with the exception of the Smart Round Thermostat (formerly known as the Lyric Round).
Is C wire hot or neutral?
The C wire is more like a neutral wire (in electrical terms) and it completes the electrical circuit between the furnace (or any heating system) and the thermostat, thus ensuring a flawless power supply to thermostat even when the furnace is OFF.
Is the C wire just a ground?
C stands for common. The common wire is the ground or negative wire. To complete the circuit that provides power to the thermostat you need a positive and negative wire from the 24V transformer. Some thermostats have batteries that power them and they serve only as a switch to operate the heating or cooling unit.
Can you connect C wire to ground?
Wiring to the ground @ any outlet would potentially work, but is not good practice,as many things could go wrong and possibly short or overload the circuits in your furnace controls, not good! Happy trails. Hello, and welcome to Home Improvement. Thanks for the answer; keep ’em coming.
