Is my boss therm unit working properly ?

I have finally got my unit to turn on and off at set times ,but when the correct temp is reached the heating goes off and then never seems to come back on again,this maybe because it is still saying 22c and that is what I set it at ,but I feel that the thermostat is not working correctly as it does not feel that warm.it feels as if the boss therm unit takes for ever to decide that the temp in the room has dropped a few degrees ,does anyone else have this problem?