What do the colored wires on my thermostat mean

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 are the color codes for thermostat wiring?

• The W wire is connected to your heating system. …
• The Y wire is yellow and connects to your air conditioning compressor.
• The G wire is green and connects to the fan.
• Rc and Rh: The red wire(s) are the power source for your thermostat.

How do you identify thermostat wires?

Look for connectors that have labels that are the same as your thermostat. For instance, you might find labels like R, W, G, Y, C or O/B. You should find wires attached to these connectors that are the same color as the wires that connect to your thermostat.

What are the 4 wires on a thermostat?

• Red wire for power (24V).
• White wire for heating (connected to W or W1 terminal).
• Green wire for fans.
• Blue or yellow wire for cooling (connected to Y).

Are thermostat wire colors Universal?

There is no universal color used for this thermostat terminal designation. * These colors may be different if the person who wired the thermostat didn’t use conventional color coding. Most technicians use the colors specified.

What color is the common wire?

Red, Black, and White are the colors of switch wiring for three-ways. Red and Black are connected to the switches if the White is used for neutral. The White is often referred to as Common, but the colored wires are also used as hot wires.

What color wire goes where on a Honeywell thermostat?

Meaning of Wiring Terminal Letters W (white) controls the auxiliary heating elements. Y (yellow) controls the compressor on the cooling system. G (green) controls the fan. C (blue or black) provides a return path to the transformer.

What is the orange wire on a thermostat?

Orange Thermostat Wires You will only see an orange wire in your thermostat if your system has heating. These orange wires directly link to your outdoor condense that reverses valve operation from one setting to another. It is important to note that sometimes you will see a dark blue wire instead of orange.

What color is 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.

What are S1 and S2 wires on thermostat?

L: This terminal is designated for indicator lights on the thermostat, sometimes for when auxiliary or emergency heat is turned on, or if there’s a general problem with your system. … S, S1, S2: These wires run directly outside and provide outdoor temperature information to the thermostat.

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What color wire is W2?

Traditional Thermostat Wire Color CodesColorTerminalUseLight Blue 2Y2Switched to CoolingWhiteWSwitched to HeatingBrown 3W2Switched to Heating

What color is the B wire on a thermostat?

MarkingWire Color CodeDescriptionY2YellowSecondary cool call relayGGreenFan relayOOrangeChange-over relay to cool relayBBlueChange-over relay to heat relay

What does the blue wire mean?

Blue wires are used as travelers, usually on three- or four-way switches (controlling a light from multiple locations) or as switch legs for things such as fans or lights. Yellow wires are almost always used as switch legs for outlets, fans, or lights.

What do the colors mean in electrical wiring?

Electrical wiring comes in one of several colors: Black Wires – when you see a black wire, always assume it’s live. … Blue Wires – always assume they are live if you have power. Blue wires are also fed through a conduit, usually bringing power to three or four-way switches. Green Wires – green wires are grounding wires.

What color is the positive wire?

Positive – The wire for the positive current is red. Negative – The wire for the negative current is black. Ground – The ground wire (if present) will be white or grey.

Is a orange wire positive or negative?

Positive Wire Color (480 VAC) The colors commonly used for this type of positive wire are brown, orange or yellow. The wire cannot be white, gray, green or green and yellow striped.

What does the blue wire do on a thermostat?

The blue wire, or C-wire, is known as the common wire. It’s there to provide power to the thermostat. Older thermostats usually don’t have a C-wire because they either don’t need power or, if they do, they get it from a battery.

What happens if you wire thermostat wrong?

Potential consequences of improper installation could include: Electric shock. Blowing a circuit breaker. Damaging the thermostat unit, the electrical system or even the AC/furnace unit itself.

How do you wire a 4 wire thermostat?

1. Red Wire = Rh = Power.
2. White Wire = W = Heating Wire.
3. Yellow Wire = Y = Cooling Wire.
4. Green Wire = G = Fan Wire.
5. Blue Wire = Y = Cooling.

Why is there a jumper between R and RC?

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.

What is RC and 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.)

What are the terminals on a thermostat?

A basic circuit needs a source, a path, and a load. In this case, the source is the transformer, the load is the thermostat, and the path is the R terminal and the C terminal which provides the path back to the 24-volt transformer. The O Terminal is the control for the reversing valve in most brands of heat pumps.

How many thermostat wires do I need?

Most systems today require a minimum of 5 wires when both heating and air conditioning equipment is included in the system. Our pro recommendation is to use 18/8 wire.

What is the Y2 wire on a thermostat?

Y2 is the thermostat wire for second stage of cooling. Y wire is for the first compressor (air conditioner units) and Y2 wire is for the second compressors (air conditioner unit). Y2 wires apply only if you have two air conditioner compressor units running from one AC thermostat.

Does R go to RC or RH?

Here are some general guidelines: 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. … These are not jumper wires, and you can insert the Rc wire into the Rc connector and the Rh wire into the Rh connector.

What does o B stand for on a thermostat?

The O/B terminal is for heat pump systems and is used for the reversing valve. When the “O” option/position is selected the reversing valve defaults to the heating mode. If the “B” option/position is selected the reversing valve defaults to the cooling mode.