The RC wire (C for Cooling), if connected properly, controls your HVAC cooling. The RH wire (H for Heating) provides power to your HVAC heating. If you are planning to replace your home thermostat, it will be essential that you know which wires to connect to the right terminals in your thermostat.
Besides, do I use RC or RH?
If the air conditioning thermostat has one transformer to power both the heating and cooling system, then the wire from the transformer goes directly to the RC terminal and is called the RC wire. Effectively there isn’t a second RH wire, although there is an RH terminal. This wire is also known as the RH wire.
Also, do I need a jumper from R to RC? Rc and R are the same terminal. For nest you don’t need a jumper. The reason for the 2 terminals is so you can use one thermostat for 2 types of units. Rc is for the indoor air handler when you run the AC.
Moreover, what does RH and RC mean on a thermostat?
Rh stands for Red-Heat and Rc stands for Red-Cool. If you only have a single red wire the jumper between Rh and Rc are required for some heating and cooling hybrid systems depending on your thermostat. Yellow/Y is the AC compressor. White/W is the Heating element.
Is R and Rh the same on a thermostat?
R , Rh , and Rc are all the same, but not. In general terms, the R terminal is where you connect the signal voltage source. This allows current to flow from “into” the R terminal and “out of” the appropriate signal terminal ( W , Y , etc.) of the thermostat.
17 Related Question Answers Found
Is the C wire a ground?
The C wire is the common wire ground wire. You already have 24v ac going to the red wire. If you have an extra wire connect it to the C at the thermostat and ground it at the transformer box in the AC unit.
Is RC and C wire the same?
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. Other times they are the same wire. In that case it will typically be labeled Rh/c.
What is the O B Wire?
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 Rh wire?
Rh. If you don’t have an Rc wire, the Rh wire is the power wire for both your. heating and cooling systems. If you have an Rh and an Rc wire, the Rh wire is the power wire for your. heating system.
Does thermostat need jumper wire?
Because many thermostats come with a pre-installed thermostat jumper wire that connects these terminals, you only need one red wire, which could be the thermostat Rc wire or the Rh wire. If you don’t, you’ll need two red wires so you can connect each terminal separately to the system transformer.
What color is RC wire on thermostat?
Thermostat Wiring Color Code Chart Marking Wire Color Code Description Marking Wire Color Code Description Rc Red Power from cooling, 24 Vac transformer Rh Red Power from heat, 24 Vac transformer C Black/Blue Common of 24 Vac transformer
What does Y mean on thermostat?
Y= the cool load. On a call for cooling the thermostat closes a switch between R and Y, sending 24v to energize the cooling circuit. G= the fan load. On a call for cooling the thermostat closes switches between R and Y and also R and G energizing both cooling and fan cicuits.
What does G mean on a thermostat?
Thermostat Terminal Letters 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. RC: The RC terminal is the 24-volt cooling power supply. RH: The RH terminal is the 24-volt heating power supply.
How many wires does a thermostat need?
In the most basic system, this functionality is provided by use of a fan center relay, and the low voltage wiring to the thermostat now will require a minimum of three wires (for heat only units) and four wires (for heat / cool / fan) for control.
What color is the common wire?
The “common” is the “neutral” or “ground” wire, depending on the type of circuit. In normal US residential wiring, you’ll have a black “hot” wire, a white “neutral” or “common” wire, and a green or bare “ground” wire.
Can I use RC wire as C wire?
A red wire on the RC/RH terminal, a green wire on the G terminal, a yellow wire on the Y terminal and a white wire on the W terminal. None of these wires can be used to substitute as a “C” wire.
Where do you connect the C wire on a boiler?
To get a C wire to one or more of the thermostats, you’ll simply run a wire from the other side of the transformer on the wall. The original wire from the transformer should be connected to the R terminal on the thermostat, while the new C wire should be connected to the C terminal on the new thermostat.
Will a Nest thermostat work with two wires?
Nest thermostats can work with systems that use Service Light (L) wires. While L wires can’t be connected to the Nest thermostat, they don’t need them. The Nest thermostat and Nest app will show you system status information without connecting L wires.
What does RH mean on a thermometer?
What is the use of jumper wires?
The term “jumper wire” simply refers to a conducting wire that establishes an electrical connection between two points in a circuit. You can use jumper wires to modify a circuit or to diagnose problems in a circuit.
Can I install Nest myself?
It’s easy to install a Nest thermostat yourself on most systems. But if you’d like some help, you can have a Nest Pro install your thermostat. After they’ve installed your Nest thermostat, they can give you a demo and answer any questions you have.
How do you install jumper wires?
Installing Jumper Wires. Grasp the end of the wire with needle-nose pliers and smooth and straighten it by pulling it between the pinched thumb and forefinger. Clip the wire to extend about 1/4” (5mm) beyond each hole for the jumper. Use the needle-nose pliers to make a bend at about 1/4” (5mm).