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.

How do you tell which wires are which on a thermostat?

Thermostat Wiring Tips

The W wire is connected to your heating system. If your thermostat controls your heat, you will have a white wire. The Y wire is yellow and connects to your air conditioning compressor. The G wire is green and connects to the fan.

What color wire goes where on a thermostat?

In general, the thermostat wire colors match the first letter of terminal names such as Red Wires for R terminals (for Power), Yellow Wires for the Y terminal (for Cooling), White for the W terminal (for Heating), Green Wires for the G terminal (for the Fan).

What are the 5 thermostat wires?

What happens if you wire a 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 to Identify Broken Wires on a Thermostat

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 is the common wire on a thermostat?

The C-Wire, or “common wire” enables the continuous flow of 24 VAC power to the thermostat. It's a wire that (if you have one) runs all the way from your furnace to your thermostat.

What color is common wire?

White. The "common" is the "neutral" or "ground" wire, depending on the type of circuit. In normal US residential wiring, you'll have a black "hot" wire, a white "neutral" or "common" wire, and a green or bare "ground" wire.

What is blue wire for in thermostat?

Blue wires are for heat pumps. This wire connects to terminal B on your thermostat.

What is Rh and RC 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.)

Does 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.

What are S1 and S2 wires on thermostat?

S, S1, S2: These wires run directly outside and provide outdoor temperature information to the thermostat.

What do I connect the blue wire to?

The blue wire from the ceiling fan gets connected to the second live wire from the ceiling. This second wire can vary in color but is most commonly red or black. This connection allows you to power your lights from the second switch.

What is the green wire on a thermostat?

Green wires in thermostats control your fan for your air handler or furnace. You should be able to trace this green wire directly from your G terminal on your thermostat to your heating system.

What is the brown wire for on the thermostat?

The brown wire is what connects a thermostat to an emergency heating system, a backup heating system used if your heat pump ever fails. If the brown wire is not connected to the thermostat, it is because your thermostat's HVAC system model doesn't have an emergency system connected to it.

Which wire is hot when both are same color?

In most modern fixtures the neutral wire will be white and the hot wire is red or black. In some types of fixtures, both wires will be the same color. In this case, the neutral wire is always identified by some means. In some cases, there will be small writing on the wiring case.

What do the wire colors mean on a 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).

Is the common wire the hot wire?

Black wire: This is a hot wire that carries electricity from the power source to the first switch in a typical 3-way setup. It's also called the “common wire” or the “line wire.” Unless the breaker is off, this black wire is always hot.

What is the difference between R and RC on a thermostat?

R in general

R , Rh , and Rc are all the same, but not. In general terms, the R terminal is where you connect the signal voltage source. In low voltage controlled systems, there will be a step down transformer that provides the power to the control circuitry.

Where do I connect the C wire on my thermostat?

If your system has a C-wire, it might be in use or just tucked away behind your current thermostat. If your system doesn't have a C-wire, you'll need to run a new cable from your furnace to your thermostat to install most of the modern smart thermostat models.

What does AC wire look like for thermostat?

You will probably see a few wires connected to some labeled terminals. If you happen to see one connected to the terminal labeled “c”, then you are in luck. You have a c wire! It's kind of hard to see, but the blue wire on the right is labeled “c”.

What are common wires?

The common wire is normally the white wire, at least in the United States, and is often called the neutral wire. It's also called common because all circuits in the house typically have the white wires tied together, which means every circuit has that wire in common.

Can blue and black wires go together?

The black and blue wires need to be connected. You will be able to control your fan and lights with a single switch. You should twist the black and blue wires the same way you did the previous wires.

Which is the live wire black or blue?

The live wire is brown in new systems and red in old systems. The neutral wire is blue in new systems and black in old systems.