I did an experiment with one of those inside / outside thermometers ( with one of the temperature sensors in a probe on end of a cable ). In manual with ambient around 20 cabin temp set to 20 deg, poked the probe down a vent and starting from cold monitored the temperature of air coming out of vents, after less than half a mile I was up to over 50deg C after a few miles it was dropping rapidly and got down to about 16deg, you could fool it to keep blowing warm air by continually tweaking the set temperature upwards, and the cabin got hotter until the temp sensor got to temp, and then it would blow cold air again. I would just like it to blow warm air, at the temperature me and her indoors find agreeable and not a cold draught, is it too much to ask..