I have that too-cold air out of the screen and warm air on my feet. I also have no cable contol over the pods. At the moment I have them jammed open for the heat, in the summer jammed closed for no heat. My heater controls have 4 sliders as well. When I looked at the heater cables to the pods at the back of the lever, from memory there were 3 cables attached. I always say in the summer I'll have a look but never do. I might get some cables and try and sort it before winter really kicks in. I don't think they make a coat thick enough!
my bay window system worked very well but it had genuine german heat exchangers, apparently some makes are very poor and dont produce the heat.
critical not to get oil on them cause it WILL make you ill.
problem i had in the summer was it leaked hot air through even when off in the end i resorted to disconnecting the heat system for the warmest days of summer.