Does my heat pump use O or B wire?

On many other thermostats, the O wire is typically connected to a terminal marked W on one side and O or O/B on the other side; the W is for use with a conventional system (furnace) while O/B is for use with a heat pump.

How do you wire a new thermostat wire?





Quote from the video:
Quote from Youtube video: Into the W terminal and the green wire into G or the fan tighten that one up as well. Okay. So we have the thermostat hooked up and then of course this wire goes into the wall and down to the furnace.

How many wires does a heat pump thermostat need?

In heat pump system, there are at least 8 wires that need to be connected to the thermostat for proper operation.

Why is there a jumper between R and RC?

In most cases, the heating and cooling system share a single transformer by leaving the jumper in the lower right corner it connects the RC and RH to power heat and cool features.

How do I know if I have B or O wire?

Check the configuration. 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. The system uses the O terminal if the reversing valve turns on while running cooling mode.

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.

What color wire goes where 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).

Where do the wires go on a thermostat?

The white wire underneath your thermostat connects to your heating system. It terminates at your air handler or furnace. The white wire connects to terminal W in industry-standard thermostats.

How do you wire a 3 wire thermostat?

Here is how to wire a 3 wire thermostat:

  1. Remove the control panel of the old thermostat.
  2. Take a picture of the 3 wires. …
  3. Remove the motherboard of the old thermostat completely, and secure the wires. …
  4. Put the new motherboard in the place of the old one, and pull the wires through the 3 wire thermostat.

Does R wire go to RH or RC?



An R wire can go into a Nest Learning Thermostat’s Rc or Rh connector.

Does red wire go to R or RC?

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. If you only have a single R wire, then it will only have an R connector, which is the connection you’ll use.

Is RC wire same as C wire?

No the Rc is the red wire. You need 5 wires or more for this to run with all the functions. You can use one of the other wires but you have to drop control of the fan. It will only come on when furnace comes on.

Can I use R as C wire?



If the black wire on the R terminal goes to the thermostat and only the thermostat, you can safely move it over to the C terminal. The AC and humidistat being hooked up to C is correct. R and C together carry the 24v power that a smart thermostat (and some programmable models) use for power.

How do you identify C wire?

Quote from the video:
Quote from Youtube video: Likely there is gonna be a fifth wire tucked into the wall I'm thinking that's going to be our C wire most likely because as you can see we have a green a yellow a white in a red.

What do thermostat wire colors mean?

The red wire is the one that powers the thermostat, the green wire connects to the fan, the white wire is connected to the heating system, and the yellow wire is responsible for the cooling system. Smart thermostats usually have a common wire that is either blue or black.

What is common wire on thermostat?

A C-wire, or a common wire, runs from your low voltage heating system (24v) and carries continuous power to your thermostat. In today’s electric market, most newer heating and cooling systems have C-wires, which guarantees compatibility for the installation of all smart thermostats.

What does W1 and W2 mean on a thermostat?



W/W1 and W2. In a conventional system, W/W1 controls your heating system and, where applicable, W2 controls your heating system’s second stage, which helps warm the home faster.

Where does black wire go on thermostat?

This the Common Terminal, and usually, a blue or black wire is run to the transformer from this terminal to complete the circuit, and in some cases, provide power to the Thermostat. This terminal is found on thermostats designed to work with Heating Pumps and is used to power the defrost cycle on the heat pumps.

What color wire is the common wire?

Red wires are hot wires common in a 240-volt outlet or when a wall switch controls the outlet. Blue and yellow wires are hot wires for ceiling fans and three- or four-way switches. White or gray electrical wires are neutral wires.

Is the common wire black or red?

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.