I took another look at the ATC800+ connections and the heating and cooling outputs were cross connected. My mistake , but the manufacturers have swapped the heating and cooling connections, so be careful if you replace your 800 for an 800+ because the connections are not the same. Luckily i caught it before any damage was done, otherwise, the heater would have increased the temperature to whatever the 800+ maximum limit is whilst the ATC 800+ was thinking it was cooling! I'm an avionics engineer by trade. Scary isn't it
