An R wire is similar to either the RC or the RH, so if you don’t have an RH wire, the R wire will be in place to control the heating system. What color wire powers the Nest thermostat? To wire up your Nest Thermostat, simply: Connect the Red wire from the transformer to either the RC or RH terminals (as they are connected internally) Run the White wire from the furnace on the W terminal.
What is the difference between RC and Rh wires?
You may have distinct Rh and Rc wires which come out of the wall and are connected to your system if you have individual heating and air conditioning systems. But those are not jumper cables, and the Rc wire can be inserted into the Rc connection while the Rh wire can be inserted into the Rh connector.
What is the RH and RC wire on a thermostat?
Every thermostat contains RH and RC wires. Depending on your thermostat, some heating and cooling hybrid systems require a jumper between Rh and Rc in case you only have a solitary red wire. The AC compressor is represented by the color yellow/Y.
What does the R wire do in HVAC?
If you just have an R wire, it’s responsible for powering your entire HVAC system (through the use of a transformer ). If you have both an Rh and an Rc wire, the former powers the heating and the latter powers the cooling (using two separate transformers). If, for example, you have an R wire and an Rc wire, the R wire controls the heating system.
What does RC and Rh mean on a circuit board?
When you look at a circuit board or an instruction manual, you may notice a confusing array. RC and RH are the positive terminal connection ports for 24 volts AC from your thermostat or air handler. There is usually a jumper from RH to RC if you only have one supply of 24 VAC.
Is RC the same as R?
RC is no different and simply means red cooling. The wire is generally red, although there is no color standardization -- but more importantly, the "R" really means that the wire and terminal are hot; it's a live electrical wire. The RC wire connects to the RC terminal, which controls the cooling system.
Is Rh wire same as R?
R , Rh , and Rc are all the same, but not. In general terms, the R terminal is where you connect the signal voltage source. In low voltage controlled systems, there will be a step down transformer that provides the power to the control circuitry.Apr 2, 2015
What is R and RC wire?
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.Oct 25, 2014
What is RC or RH on a thermostat?
RC: The RC terminal is the 24-volt cooling power supply. RH: The RH terminal is the 24-volt heating power supply. (Note: The RC and RH terminals are jumpered together in a four-wire heat/cool system and a single-stage heat pump system but not in a five-wire heating/cooling system.)Feb 24, 2022
What is an R wire?
The R wire is the power wire for your heating and cooling system. If you only have one R wire (no Rh or Rc), you can connect your R wire to either Rc or Rh on the Nest thermostat.
Where does Rh wire go on thermostat?
The Rh wire connects to your heating system as opposed to your cooling system. This wire may be red without an H attached to it, depending on if you have a dual transformer setup. The Rh wire connects to the RH terminal on your thermostat.Feb 4, 2020
What is the Rh wire on the Nest thermostat?
The Rh wire is a kind of red wire that provides electric power from the transformer 24×7. Unlike your cooling system, the Rh wire connects to your heating system. If you have a dual transformer setup, this wire may be red without an “H” linked to it. The Rh wire connects to the RH terminal on your Nest thermostat.Apr 1, 2022
What is white wire on thermostat?
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 does the red wire mean on a cooling system?
The wire is generally red, although there is no color standardization -- but more importantly, the "R" really means that the wire and terminal are hot ; it's a live electrical wire. The RC wire connects to the RC terminal, which controls the cooling system.
What is a RC terminal?
RC: The RC terminal is the 24-volt cooling power supply. RH: The RH terminal is the 24-volt heating power supply. (Note: The RC and RH terminals are jumpered together in a four-wire heat/cool system and a single-stage heat pump system, but not in a five-wire heating/cooling system.)
What is the name of the wires that give the power supply?
Typically, the wires that give the power supply (usually termed as the 'hot' wires) are marked Rc (for cooling) and Rh (for heating). They give a 24-volt power supply from the HVAC system's control panel.
Is Rc the same as R?
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.
What does RC mean in electrical?
RC is no different and simply means red cooling. The wire is generally red, although there is no color standardization -- but more importantly, the "R" really means that the wire and terminal are hot; it's a live electrical wire. ...
What does the R mean on a thermostat?
The "R" still indicates it's a hot wire and terminal connection , and the "H" simply means heating. The RH wire connects to the RH terminal and controls the heating part of the thermostat.
Is there a second RH wire?
Effectively there isn't a second RH wire, although there is an RH terminal. However, the heating still needs to be controlled, so a wire known as a jumper is connected between the RC and the RH terminals so that power gets to the heating control part of the thermostat. This wire is also known as the RH wire. Advertisement.
Basic functions of RC and RH terminals
Many homeowners want to replace a faulty HVAC thermostat themselves but are not electricians or technically trained people. They can sometimes get confused with the terminals marked “RC” and “RH.”
Wire the RC and RH terminals correctly when installing a new thermostat
You will most probably only worry about the terminals and what the markings on them mean when you are either troubleshooting or replacing an existing thermostat.
Terminals other than R, RC and RH
It is always good to know what the terminal indications, other than R, RC and RH mean. The other most commonly terminals found on thermostats are:
What happens if terminals are wired incorrectly
With all this said, you might wonder what happens if you wire a thermostat incorrectly. Potential consequences include electric shock, blowing a circuit breaker, and in severe cases damaging the thermostat unit, the electrical system or even the furnace or air conditioning units themselves.
What is a K wire?
K: Honeywell wire saver modules combine the Y and G wires to form a single K wire that connects to the K terminal on some Honeywell thermostats. It’s used for systems that don’t provide a C wire but have a thermostat that requires one.
What is the Y wire on a thermostat?
Y, Y1, Y2: Whenever your thermostat calls for cooling, the Y wire is used to send a signal to your HVAC system telling it to fire up the air conditioner. Y1 and Y2 wires might be used instead if you have a two-stage system (i.e. a high level for extremely hot or cold days, and a low level for mild days). W, W1, W2: Just like the Y wire, the W wire ...
What does C stand for in HVAC?
C: This stands for the “common” wire in an HVAC system, and it provides power to the thermostat. Some systems don’t provide this, and it’s not necessarily required by every thermostat, since some can be powered by a battery or just “ steal ” power from other wires, but if your system has one and there’s a terminal for it on your thermostat, you should absolutely connect it.
What is the signal wire for heating and cooling?
In some systems, both the heating and cooling systems use their own signal voltage. In these cases, the signal wire from the heating system will be connected to R or Rh, while the signal wire from the cooling system will be connected to Rc. If only a single signal wire is used, the R terminal will be electrically connected (jumpered) ...
What happens if only a single signal wire is used?
If only a single signal wire is used, the R terminal will be electrically connected (jumpered) to Rh and/or Rc.
Is R the same as Rc?
R in general. R, Rh, and Rc are all the same, but not . In general terms, the R terminal is where you connect the signal voltage source. In low voltage controlled systems, there will be a step down transformer that provides the power to the control circuitry.
