Most thermostats have a Red wire that is the power wire that usually connects to R & RC terminals of the thermostat, a Green wire that energizes the Fan relay, connected to the “G” terminal on the thermostat, a Yellow wire that energizes the outdoor units contactor, (if you have air conditioning) and a white wire that

What color wire is heat on thermostat?

white 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).

What color is the black wire on a thermostat?

Thermostat Wiring Color Code ChartMarkingWire Color CodeDescriptionCBlack/BlueCommon of 24 Vac transformerWWhitePrimary heat cell relayEBrownEmergency heat relayYYellowPrimary cool call relay12 more rows

What do the wire colors on a thermostat mean?

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. Green/G runs the fan.

Why is there a jumper between R and RC?

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.

Do I need a jumper between R and RC?

Instead of using jumper wires, Nest Learning Thermostats use an internal jumper between the Rh and Rc connectors. A Nest Learning Thermostat will automatically use this internal jumper if your system needs it. Important: Never put more than one wire into a Nest thermostat connector.