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.

How do you wire a thermostat to a heat pump?

Quote from the video:
Quote from Youtube video: It's gonna connect in the thermostat. It's gonna go back over to the air handler control board once that air handler control board sees the 24 volts on the g terminal.

Does your heat pump use an O wire or B wire?


If you have a heat pump and your thermostat doesn’t have a separate wire labeled O, then the wire labeled B should be connected to the Nest thermostat’s O/B connector.

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

O stands for orange and B for dark blue.

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.

What is the B terminal on a heat pump?

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.
Feb 9, 2015

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.
Sep 4, 2018

What color wire is heat on heat pump?

The Blue or C Wire

(It’s important to determine that your heat pump is compatible with your thermostat before you decide.) C wires or varying colors apply to every thermostat, but blue C wires belong to thermostats attached to a heat pump. Blue wires are for heat pumps.
Feb 4, 2020

Will any thermostat work with heat pump?

Thermostats always improve the energy efficiency of heat pumps as it regulates the system really well. A good thermostat helps to save energy and money in the long run. While choosing a heat pump thermostat, the most important fact to keep in mind is “not all thermostats are compatible with heat pumps”.
Jan 13, 2022

Is there a difference between a heat pump thermostat and a regular thermostat?

Where a standard AC thermostat uses four wires (hot wire, compressor and outdoor fan wire, indoor blower wire, battery wire) to run the unit, a heat pump thermostat requires a fifth wire to handle the change in the reversing valve. These wires are usually color-coded, and the reversing wire is the brown wire.
Nov 17, 2013

Why is my heat pump not working?

If the heat pump is not turning on, check if the power socket has been switched on. If the power source is on and it is still not working, check to see if the fuse in the heat pump has been tripped or blown. If the fuse is the issue, reset it or replace it, depending on the situation.
Jul 29, 2019

What is the C wire on a thermostat?

A common wire (C-Wire) provides Wi-Fi thermostats continuous power by connecting it to a heating and cooling system (e.g. furnace). C-Wires are required on most Honeywell Wi-Fi thermostats, with the exception of the Smart Round Thermostat (formerly known as the Lyric Round).
Apr 21, 2022

How do I bypass the C wire on my thermostat?

Quote from the video:
Quote from Youtube video: Connect the extra wire to the C terminal of Union thermostat trace the extra unused wire from the thermostat to the furnace board make sure it's connected to the C.

Is RC and C wire the same?

The C and Rc wires are not the same. To install this thermostat you should follow the exact same wiring of the previous thermostat.
Jul 24, 2019