As long as the recirculation fan is working constantly and the beer isn't freezing, nor is the evaporator icing up, you're model is probably designed that way; To keep the temp exactly within +/-1° of the setting. Commercial units are made for consistancy at the expense of extra hydro usage. Before everyone else, especially those with more knowledge and experience than me, show up here, it would help to know: What model is it? What temperature is it at?, Are there any leaks..is the door gasket intact? Is the temperature stable?