What does the OB wire mean?
https://www.youtube.com/watch?v=qiAOvJhq8_s What does the OB wire mean?C: This stands for the “common” wire in an HVAC system, and it provides power to the thermostat. O,...
What color wire is OB on a thermostat?
https://www.youtube.com/watch?v=xQd6GERVzVM What does OB stand for on a thermostat?The O/B terminal is for heat pump systems and is used for the reversing valve. When the...