It is only possible that your unit does not shut down for the following reasons. 1.- Remove your unit and check that your relay is in good condition and not direct. with the tester chuequea if it is an amperometric relay you place it in the vertical position that corresponds to your working position and measures that there is no continuity between your contacts that must be normally open. now turn it upside down and you should see continuity in your contacts. if in both directions it gives continuity because it is bad, it is direct and you must replace it. 2.- Remove the thermostat put it in its lower part of adjustment in temperature and with the tester it measures its two points of connection or cables according to the case. should there be no continuity, then put it a little high temperature until there is continuity in the tester takes a basin with ice cold water and you put the sensor or vulvo of the thermostat and you should see that when the thermostat is working, tester does not measure continuity. otherwise you always have continuity in the freezing water to the minimum setting of the thermostat then it is bad. this is direct and you must replace it. 3.- The last possible question for your unit to be direct is that the wires of the thermostat are simply twisted towards the unit. 4.- If it is a refrigerator and use the relog because there you also have a problem. BUT THE THERMOSTAT SHOULD WORK OFF THE UNIT UNDERSTANDING THE RELOG. But if the relog is damaged and does not send to rest the unit after the working time then the relog TRAMBIEN IS GUILTY THAT THEY ARE FREEZING TO YOU. To check the log. measure between the terminals where the cables of the unit were connected and measure if there is continuity (for logic it excists since it freezes you) but after that this continuity you take the relog knob and you turn it little by little and you will see that in a you will hear a click sound that tells you that the unit enters the rest time so cuakl at that moment you have moved it and you have reached there the tester loses continuity. this means that if the contact of the relog is good because it is sending the unit to rest. Then keep moving and in a new click that you will hear, there will be continuity again. you can do this as many times as you want and you will have the same results. THIS TELLS YOU THAT MECHANICALLY YOUR RELOG IS IN THIS PART IN GOOD CONDITION. Now measure if where the relog is fed there is resistance in the motor that makes the relog work. Because otherwise your relog is MECHANICALLY IN GOOD CONDITION BUT YOUR SMALL ENGINE THAT IS MOVING TO MOVE THE MECHANISM IS DAMAGED. IF YOU EXCISE MEN THEN CONNECT. PUT YOUR FEEDING TO WORK AND YOU CAN SEE IF THE ENGINE IS NOT TRANSFERRED AND IF THE MECHANISM IS TURNED. IF YOU FEEL THAT WORKS BECAUSE IN YOUR HAND YOU FEEL HOW IT WORKS AND YOU SEE THAT LITTLE TO A LITTLE MOVE THE MECHANISM OR THE KNOB THEN YOUR RELOG IS IN GOOD CONDITIONS. IMPORTANT NOTE: IF YOU SEE THAT YOUR THERMOSTAT AND RELAY ARE IN GOOD CONDITIONS SUSPECT DIRECTLY FROM THE RELOG IF ONE UNIT WETS THE EQUIPMENT. THE FACT THAT IN TESTS CONTINUITY AND WORK THE RELOG IS NOT SAFE INDICATE THAT IT IS IN GOOD CONDITION. I say this because if the mechanism of the relog is worn out it is difficult to open and maintain its contacts and terminals so the motor sometimes is locked up to lose even false contacts internally in its connection causing your failure to be persistent in the unit CONGELANDOTE TO THE DAYS THE THINGS AND MAKING A LOT OF ICE. If you see that your relog is very overheated in the connections and you see something of the plastic in bad conditions I recommend you replace it because those are clear indications that your relog if it is not bad is AIM OF FAILING AT ANY TIME because it is already deteriorating in your contacts creating sulfates and nearby bad contacts causing you to suffer your unit. THESE ARE THE ONLY POSSIBLE WAYS THIS UNIT IS ALWAYS ON. Sorry for the length of my explanation but I hope it will be of great help. read it carefully and you will find the source of your problem. From Maracaibo Venezuela GREETINGS .....