In the most basic form of control, the C or common terminal of the low voltage transformer is connected in parallel to all of the control relays.. The R terminal of the low-voltage transformer is connected through the thermostat to each control relay.

What is the R wire on thermostat?

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 R go on thermostat?

InstallationAn R wire can go into a Nest Learning Thermostats Rc or Rh connector.The Nest Thermostat E only has an R connector, which is typically where an R wire would go.More items

Where does the thermostat wire connect to?

The green wire underneath your thermostat connects to the fan of your furnace or air handler. It terminates at the air handler or furnace. The green wire connects to terminal G on your thermostat.

Does R wire go to RH or RC?

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.

What does R and W mean on thermostat?

W wire – heat. R wire – heat power. W wire – heat.

What does W mean in thermostat?

W wire – heat. R wire – heat power. W wire – heat. G wire – fan.

Why do most thermostats have a jumper from RC to RH?

Effectively there isnt 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.