What is the O terminal on a Honeywell thermostat?
Victoria Simmons
Published Feb 07, 2026
What is the O terminal on a Honeywell 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. It is extremely import that the correct mode is selected.
What are the terminals on a five wire thermostat?
Here are the 5 wire colors and terminals codes:
- 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).
- Black wire for “C” or “Common” wire.
What do the terminals on a thermostat mean?
Between the thermostat and the heating or cooling equipment is a set of low-voltage wires that are run from the thermostat control terminals to the. These strips of terminals have markings on them to signify the heating connection, the cooling connection, the fan connection, and heat pump connection, as applicable.
How to connect a rth221 to a Honeywell terminal?
M32154 5 69-2448ES—03 RTH2300/RTH221 Connect Wires (typical wiring) 2. Loosen the terminal screws using a screwdriver, insert the wires, then tighten the screws. 3. Push any excess wire back into the wall opening. Labels don’t match? If a wire does not match any terminal designation, see next page.
What kind of a thermostat is the rth2300?
RTH2300/RTH221 Series Programmable Thermostat Identify System Type This thermostat is compatible with the following systems: • Gas, oil or electric furnace • Central air conditioner • Hot water system with or without pump • Millivolt system • Central heating and cooling system
How to install a Honeywell rth thermostat for home?
Honeywell RTH Thermostat Installation Instructions– a detailed step-by-step tutorial, giving you the confidence Diagram of the Evcon Thermostat Screws. View and Download Honeywell RTH quick installation manual online.
What is the wiring diagram for a Honeywell thermostat?
Wiring Diagram For Honeywell Thermostat >>>CLICK HEREwire programmable thermostats / digital thermostat, 7-day progrHow to replace. Honeywell Thermostat Wiring Diagram Wires. Honeywell Thermostat Wiring Diagram Wires.
M32154 5 69-2448ES—03 RTH2300/RTH221 Connect Wires (typical wiring) 2. Loosen the terminal screws using a screwdriver, insert the wires, then tighten the screws. 3. Push any excess wire back into the wall opening. Labels don’t match? If a wire does not match any terminal designation, see next page.
RTH2300/RTH221 Series Programmable Thermostat Identify System Type This thermostat is compatible with the following systems: • Gas, oil or electric furnace • Central air conditioner • Hot water system with or without pump • Millivolt system • Central heating and cooling system
Honeywell RTH Thermostat Installation Instructions– a detailed step-by-step tutorial, giving you the confidence Diagram of the Evcon Thermostat Screws. View and Download Honeywell RTH quick installation manual online.
Wiring Diagram For Honeywell Thermostat >>>CLICK HEREwire programmable thermostats / digital thermostat, 7-day progrHow to replace. Honeywell Thermostat Wiring Diagram Wires. Honeywell Thermostat Wiring Diagram Wires.