Honeywell Thermostat T87f

Are you talking about the adjustment for the thermometer indicates the actual temperature inside your house? Who is in the lid when you remove the base and you just turn the center screw in white plastic. If you mean the knob on the base itself, which is an anticipation of the heat and you really should not mess with it unless you know what you do. If you try to set the thermostat itself to you in this race. You will notice that one of the screws holding the base on the wall is a machine. You can loosen the screws a bit, and turn the whole base to adjust. I hope this answers your question.