Do you connect the R wire to the RC or the RH?

Author: Bernadine Boehm  |  Last update: Wednesday, April 23, 2025

If you only have one R wire (That includes R, Rc, and Rh), you'll insert it into the Rc terminal on your ecobee. With dual-transformer systems you'll have two R wires—one from the cooling transformer (Rc) and one from the heating transformer (Rh). Learn how to install an ecobee thermostat in a dual-transformer system.

Does R go into RC or Rh?

An R wire can go into a Nest Learning Thermostat's Rc or Rh connector. The Nest Thermostat E only has an R connector, which is typically where an R wire would go.

Is R the same as Rh?

Some units don't have an RH wire, but instead, they have an R wire. 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.

Where does the Rh wire go?

The Rh wire on your thermostat connects to your heating system as opposed to your cooling system.

How to jumper wire from RC to Rh?

To create a new jumper for RC/RH, use a short piece of thermostat wire, strip the insulation off both ends of the wire and bend it in half. Connect one end to RC and the other end to RH on the wall plate. Leave the wire that comes out of the wall attached to either RC or RH.

Does the red wire go to R or RC on thermostat?

Should there be a jumper between R and RC?

If you have two wires, R or RH go into the R terminal and RC into the RC terminal. If you have more than one wire (for example, you have a wire labeled R and another wire labeled Rc), remove any jumpers between the R and Rc terminals or push the switch to open the RC terminal to insert a wire.

Can I connect RC and Rh wires together?

Rc and Rh: The red wire(s) are the power source for your thermostat. If your thermostat is dedicated to air conditioning only, it will have a red Rc wire. For heating and cooling systems, it will have a red Rc and a red Rh wire. Though both wires are red, they are not interchangeable.

Does it matter which wire goes where?

It doesn't matter which connection with a simple switch, but it may matter on a smart switch, dimmer, timer, motion sensor, etc. The switched hot (usually red) wire goes to the other connection on the switch. If the switch requires neutral, connect the white neutral wire to the appropriate connection.

Do I use Rh or RC on Nest thermostat?

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. Important: Don't connect any Jumper wires to the Nest thermostat. If you don't have an Rc wire, the Rh wire is the power wire for both your heating and cooling systems.

What does no power to Rh wire mean?

This means that the wire isn't sending voltage to your thermostat. Some wires, like a C or R wire, need to send voltage to keep your thermostat powered on.

What is the R in Rh factor?

The Rhesus factor, or Rh factor, is a certain type of protein found on the outside of red blood cells. People are either Rh-positive (they have the protein) or Rh-negative (they don't have the protein). This is important when you're Rh-negative and pregnant with a fetus who's Rh-positive.

What is R positive and Rh negative?

Most people are Rh positive, meaning they have inherited the Rh factor from either their mother or father. If a fetus does not inherit the Rh factor from either the mother or father, then the fetus is Rh negative. When a woman is Rh negative and her fetus is Rh positive, it is called Rh incompatibility.

Is RC the same as R?

If you only have one R wire (That includes R, Rc, and Rh), you'll insert it into the Rc terminal on your ecobee. With dual-transformer systems you'll have two R wires—one from the cooling transformer (Rc) and one from the heating transformer (Rh).

Where does the black wire go on a thermostat?

The cooling wire connects the thermostat to a compressor. Black (Or Blue) Wire is the so-called C wire or common wire. It is a 24V common wire that is linked to the transformer.

Does R wire go into Rh or RC?

The placement of the R wire, also known as the power or 24-volt wire, depends on the specific HVAC system and thermostat setup. In most cases, the R wire is connected to either the RC (cooling) terminal or the RH (heating) terminal on the thermostat.

Which wire is hot on a 2 wire 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).

Which Nest Thermostat controls humidity?

Nest Learning Thermostat (4th gen) can automatically adjust your humidification setpoint based on the outdoor weather.

What happens if you wire positive and negative backwards?

It can also cause fire if the reverse polarity goes undetected and damages wires or components that lead to sparks, which in turn causes a fire. And the worst is still yet to come, if you keep your outlet reversed you are increasing the potentials of electrical shocks.

What order do wires go in?

Step 4: Now we're making progress rewiring the plug – next you need to put each wire into the appropriate terminal pin, and tighten with the screw to secure the copper in place. Start with the live (brown), then the neutral (blue), and finally the green and yellow (earth).

Which side of a 110 outlet is hot?

A receptacle's top two slots, or “eyes,” are meant for the vertically aligned plug prongs, while the rounded bottom slot is intended for the ground prong. At a casual glance, these two slots look the same but look closer, and you'll quickly see one slot is smaller than the other. This is the hot side.

Where do you connect RC wire to Nest?

Note: If you have an R, Rc or Rh wire, you can put it into the R connector on the Nest Thermostat. If you have a W2, Y2 or O/B wire, you can put it into the *O/B connector, if needed.

Is com 24V the same as c wire?

iDevices Thermostat requires a 24V common or 'C' wire, which provides continuous power for features like Wi-Fi connectivity and the backlit display.

What does OB mean on a thermostat?

O/B: This option selects the type of reversing valve for heat pump systems. An “O” reversing valve is energized when cooling and a “B” reversing valve is energized when heating. Most systems use an O type reversing valve.

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