Why is Nest not detecting wires?

Your Nest thermostat might not sense your wiring if the wires for your heating and cooling system are too thin. Nest thermostats require wires between 18 and 22 gauge, which is standard for residential heating and cooling systems. Anything smaller than 22-gauge wire could be too thin for a Nest thermostat to detect.

Where does RC wire go on 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. Gently tug each wire to check they’re secure, and make sure each connector that has a wire stays down.

What happens if Nest doesn’t have C wire?

In a system with a C-wire, the Nest charges itself from the C-wire’s current and all is fine. In a system without a C-wire, though, Nest recharges its battery when the heating or cooling runs. It diverts a little bit of the power to itself and charges its own battery.

What is the RC wire on a Nest Thermostat?

Description. R. 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.

Why am I not getting power to my Nest thermostat?

Nest Thermostat. If your Nest Thermostat won’t turn on, the batteries could have drained or there could be a power issue. If there’s a power issue, your thermostat’s battery will drain and it’ll turn off Wi-Fi, the display, and other features to preserve battery life.

Do I use RH or RC on Nest thermostat?





The Nest Thermostat E only has an R connector, which is typically where an R wire would go. If you have separate heating and air conditioning systems, you might have separate Rh and Rc wires that come out of the wall and are connected to your system.

Is RC the same 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.

Do I need a jumper from R to RC?

If you just have one wire, regardless if it’s labeled RC, it will go into the R terminal, and the jumper connecting terminals R and RC will be in place. Some thermostats have a jumper switch, some have a metal staple, others may have a plug, and the jumper may also just be a wire connecting the two terminals.

Do I use R or RC on thermostat?

In a thermostat, the R wire is responsible for powering the entire HVAC system (through a transformer). If you have both an Rh (Red-heat for powering the heating) and an Rc (Red-cool for powering the cooling), then the R wire can be connected to either Rh or Rc.

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.

When Nest says no power to Rc wire?

What does E73 mean on a Nest thermostat? The E73 error on your Nest thermostat indicates that there is no power detected to the Rc wire. To fix this error, check your wiring, air filter, drain tubes/drip pans, and HVAC fuse and ensure that all of them are working correctly.

What color is the C wire?

Blue wires



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 color wires go on a Nest thermostat?

Quote from the video:
Quote from Youtube video: The Y wire is yellow. And that is the cooling wire or AC wire.

Does Nest require C wire?

These wires get the power from your heating system, cooling system, or your furnace, and make sure that your thermostat doesn’t need to be recharged. According to the Nest website, your Nest thermostat will work without a C-wire but specialists still recommend using an adapter if you can’t get a C-wire installed.

How do you identify C wire?

Quote from the video:
Quote from Youtube video: Likely there is gonna be a fifth wire tucked into the wall I'm thinking that's going to be our C wire most likely because as you can see we have a green a yellow a white in a red.

How do I know if C wire is live?



Quote from the video:
Quote from Youtube video: Begin by putting one probe whichever probe you want on the rh wire and test every other wire with the other probe. One of the wires will show up is 24 volts and that is your c wire.

Is the blue wire the 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.

Do all WiFi thermostats require C wire?

The good news is, some of the best smart thermostats do not require the power from the C wire to work. In fact, some of the best smart thermostats like the Google Nest Thermostat have no requirement for the C wire as they contain rechargeable batteries or other technology that removes the need for one.

How do I bypass the C wire on my thermostat?

Quote from the video:
Quote from Youtube video: Connect the extra wire to the C terminal of Union thermostat trace the extra unused wire from the thermostat to the furnace board make sure it's connected to the C.

Will a Nest Thermostat work with two wires?



Both the Nest E and Nest Gen 3 Thermostats can be installed with 2 wires. The procedure to install the Nest thermostat with 2 wires is the same for both thermostats.