I have to manually set this thermostat

I hate the HVAC system in my apartment. Most HVAC units are heating and cooling combined. You set a temperature on the thermostat, and the HVAC decides whether to use heating or cooling. If it is Summer and you set it for 60 degrees, the cooling function turns on. In the Winter, at 60 degrees, you are getting the heating function. My apartment HVAC device does not do this. You have to manually set if you want heating or cooling. So in the Winter, if I don’t reset the HVAC, I could have air conditioning on. The same could happen for heating in the Summer. If I lived alone this would not be a problem. I would just set the HVAC and thermostat to what I want it. The problem is that my boyfriend lives with me and he is always hot. It is right now the Springtime. I feel it is still cold and would like heating. We both agree that 69 degrees is a reasonable temperature. The only snag is that my boyfriend sets the HVAC to the cooling function to achieve 69 degrees. At all hours of the day the air conditioning will turn on and being pumping out cold air. I hate it, especially when I am trying to sleep at night. As soon as I notice this on our thermostat, I switch the setting over to provide heating if we drop below 69 degrees. Due to my boyfriend and I have vastly different HVAC needs, this is the worst type of HVAC we could have. We both are constantly messing with it in our apartment.