Heat worked fine one day turned all controls off and over to blue on hotcold gauge Turned heat back on next day now freezing cold air blows out?
check your antifreeze leavel in the plastic bottle in the engin compartment it may be low. or it may be your thermostat on the water pump.
Ice will only form from water once water is cooled to below 0 degrees Centigrade. A freezer requires energy (ie it needs to be turned on) in order to pump heat out of the freezing compartment to lower the temperature in this compartment to below 0 degrees Centigrade. If the freezer is not turned on the temperature in the freezing compartment will be that of the room in which the freezer is kept.