I have a King KBP2406 electric heater in my shop (220V, 57oo watt). When the thermostat is set to 40° (the lowest position) the temperature in the shop is more like 50-52°. I would like to keep the shop colder (above freezing) for economy when it is unoccupied. According to King's parts data the thermostat is a 3 wire liquid filled bulb type. To save me from having to take it down and look for myself, does anyone know it there is a provision for calibration or adjustment of this thermostat?