Why does my heat pump blow cool air in heat mode or warm air in cool mode?

This is typically caused by an incorrectly configured changeover valve setting. Check Function 0190 (Heat Pump Changeover Valve) and make sure it is properly configured for your system — set it to 0 if you connected a wire labeled 'O' to the O/B terminal, or set it to 1 if you connected a wire labeled 'B' to the O/B terminal. (Page 66)