On the nest system app, when you were installing the originally, a decision had to be made whether or not the system by default as in heating mode or cooling mode. Some systems are cooling and some systems by default are heating. To switch modes you must energize the reversing valve. After they repaired your system, it seems strange that it was not working unless they change the reversing valve. In the nest setup menus, it is possible to switch the mode of the O wire from either energize with cooling or energize with heating.
I also noticed that the wires in your thermostat have much of the installation damaged and conductors might be shorting with each other. And sometimes HVAC companies that do not work with Nest installations take this action to charge you for a new thermostat. Hopefully all they did was put your old one back on.
You should be able to reinstall your nest thermostat, once it’s installed, go back to set up off the main screen, turn the dial to system, and you’ll see the set up for system type heat pump, and under there you’ll see a setting for the O. You will either choose energize for cool or energize for heat. That’s how you change the mode of how the thermostat treat your heat pump.
Ken The AC Cooling Wizard
NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
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