I'm having a bit of a problem in thermostatic control of a Heat Pump (EnergyPlus 8.8). I set the thermostat in single heating mode during winter and in single cooling mode during summer. Checking the results, I see the cooling system operating in single heating mode and vice versa. I have the same problem when I set the thermostat in single heating mode through the whole year: it actually behaves as in mode 3: single heating or cooling. I know I can solve this problem setting a proper availability to shut down the coils, but I would like to understand what I'm doing wrong here.

Edit: I'm using a VRF air to air heat pump (reference example file: DOASDXCOIL_wADPBFMethod.idf ). I get the same error in the example file. Default thermostatic control is "always 4" in all thermal zones. When I modify it to get 2 separated heating and cooling seasons (i.e. SingleHeating during winter and SingleCooling during summer), it operates as in mode 3:single heating or cooling through the whole year. I could shut down the system using availability schedule, but I don't understand why thermostatic control does not work properly with this kind of system.