Heatpump Wiring Color Convention

How do I know if my heat pump is O or B?

The heat pump is ‘O’ if it energizes in cooling and ‘B’ if it energizes on heating. Thermostats use the B terminal in systems with a reversing valve that turns on with heat mode.

Does my heat pump use an O or B wire?

The O and B terminals are for heat pumps; the B terminal is used in conjunction with Rheem, Ruud, or any other manufacturer that energizes the reversing valve in the heat pump’s heating mode. Most other manufacturers of heat pumps will utilize the reversing valve for cooling including the O thermostat.

What is the color code for HVAC?

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).

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.

What is o’b wire?

O, B, O/B: These wires are responsible for switching the changeover valve in a heat pump system. The O wire reverses the valve from heating to cooling, and the B wire switches the valve from cooling to heating. Sometimes it might be a single O/B wire instead of two separate wires.

What is o’b reversing valve?

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.

Does Goodman Use O or B heat pump?

A Goodman reversing valve is usually powered during cooling using the thermostat’s “O” terminal output. If the thermostat is set to “Cool” mode, you can check to see if it is putting out 24V on O.

What is O and B on nest?

A Nest thermostat’s star connector or. O/B connector can be used to control several different system functions, depending on what type of system you have. For example, you can use the star connector to connect a wire that controls a humidifier or dehumidifier, or emergency heat.

What does the O terminal do on a heat pump?

Quote from the video:
Quote from Youtube video: And also the reversing valve o terminal. So that's going to turn on your outdoor heat pump in air conditioning mode. So it's gonna control the compressor. It's gonna control the reversing valve and

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.

Is Rh wire same as R?

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.

Does Y go to Y1 or Y2?

In conventional cooling systems, Y/Y1 controls the first stage of cooling and Y2 controls the second stage, which helps cool down the home faster. In heat pump systems, Y1 controls your compressor, which heats and cools your home.

What does Y1 and Y2 mean?

Y1 and Y2 Wires



In standard systems, Y/Y1 controls the first stage of cooling, and Y2 controls the second stage.

What does Y1 mean on thermostat?

Y or Y1. In most systems, the Y or Y1 wire controls your cooling system. If you have a heat pump, your Y or Y1 wire controls your compressor. Your compressor is responsible for heating and cooling your home.

What’s the difference between W1 and W2?

W1 is the classification we use for galvanized steel hose clamps (according to DIN3017) that are used in no-corrosion environments. W2 is the classification for stainless steel hose clamps (combination of AISI430 and zinc plated screw) that can be used in corrosion sensitive environments.

Does white wire go to W1 or W2?

Thermostat White Wire (“W1” or “W2” Wire)



W wires go directly to the source of heating; that may be a furnace (gas, electric, oil, you name it) or heat pumps (mini-split heat pumps included). W2 is designated for two-stage heating. Most heat pumps include second-stage heating and require the white W2 wire.

Can I wire W1 and W2 together?

W1=Stage 1, and W2=Stage 2. Your thermostat wiring only has 5 wires. In order to support 2 stage heating, you’ll need to replace your thermostat wire with a 6 wire bundle instead. You would then remove the jumper between W1 and W2 and run separate connections to W1 and W2 on the Nest and W1 and W2 on the furnace.

What is W2 wire on heat pump?

W2 wire – heat. Y wire – cooling compressor. Y2 wire – cooling compressor. RH (or) R wire – power. G wire – fan.

What is W2 and Y2 thermostat?

Light Blue for Y2 Terminal. W – This is the thermostat terminal for heating. This wire should go directly to the heating source whether it be a gas or oil furnace, electric furnace, or boiler. White for W Terminal. W2 – This is the thermostat terminal used for second stage heat.

What color is W2 wire?

General Thermostat Wiring Color Code