Yes, tapping along with the red wire under the (C)OM is where it goes. If you’ll notice, your (Y) is already double taped. It works! I started from scratch, disconnecting and reconnecting every wire, and poof!, it works.Nov 1, 2014
How many wires can be connected to the C terminal at the furnace?
Two wires per terminal in HVAC work is common (though not usually correct), while 3 or more will tend to use a pigtail.
Can you share a C wire?
So, if there is only one transformer that supplies both systems, then you can jumper the C wire at the thermostats. If there are separate transformers, then you need another wire for the other transformer’s common.
What is extra wire in my thermostat?
An extra unused wire in the wall can be used as the C wire for your new thermostat. The extra wire will also need to be connected to the C (common) terminal at the heating and cooling system. This will provide power to your new thermostat.
Can I use RC wire as C wire?
No the Rc is the red wire. You need 5 wires or more for this to run with all the functions. You can use one of the other wires but you have to drop control of the fan. It will only come on when furnace comes on.
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.
Where do you connect the C wire on an old furnace?
Quote from the video:
Quote from Youtube video: The common terminal is going to be right here so if you're installing. Something you would stick the wire. Into this screw terminal from the bottom.
Is a RC wire the same as a C wire?
Typically, the wires that provide the power (often called the “hot” wires) are labeled Rc (cooling) and Rh (heating). They provide a source of 24V power coming from the HVAC control board. Sometimes they are separate wires and require separate connections. Other times they are the same wire.
Does the red wire go to RC or RH?
There is no standard for the colour of the RH wire, but most units use a red one. The RC wire, on the other hand, refers to “red cooling”. It’s the same with the RH wire in that it powers the thermostat. For the RC, it powers the cooling system.
What is the O B wire?
O and B wires control when your heat pump cools or heats your home. B. May require local pro assistance if you have both an O wire and a B wire. O and B wires control when your heat pump cools or heats your home. In some installations, the common wire may be disguised as a B wire.
How do I know if my wire is O or B?
Check the configuration. 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 Y1 and Y2 on a thermostat?
Y/Y1 and Y2. In conventional cooling systems, Y/Y1 controls the first stage of cooling and Y2 controls the second stage, which helps cool down the home faster. In heat pump systems, Y1 controls your compressor, which heats and cools your home.
What is the G terminal on a thermostat?
G: The G terminal controls the fan relay and is responsible for turning the blower fan on and off automatically or manually via the thermostat.
Can I use my G wire as a C wire?
Option #3: Use a G-Wire as a C-Wire
If there is no hidden C-wire, you can use a G-wire instead. However, you will not be able to use your fan independently when the heating or cooling isn’t running. Also, many HVAC systems are incompatible with this solution, including: HVAC systems using electric heat.
Is G wire necessary?
As you mentioned, you don’t usually need a G wire for heating mode, but you do for cooling. In special circumstances a relay could be wired up inside of the air handler to make the fan come on with a call for cooling, but normally it’s the thermostat that makes the connection that makes the fan come in in cooling mode.
What color wire goes where 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 AC wire?
Blue
The Blue or “C” 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.
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.
