Are you postive about the lower temp? The correct temp on any RV refer is BELOW 10 degrees in the freezer and 30 to 38 degrees in the main refer. The fact that you have 40 degrees in the refer and 17 to 23 degrees in the freezer is very strange. HOW are you measuring the temps---digital is needed. Does the Icemaker work? If so, your freezer is indeed below 10 degrees as the icemaker will not function if the freezer is not below 10 degrees. The freezer is NOT temp controlled by a tstat. The freezer will get below 10 degrees regardless of the tstat setting. Have you had any work done on the refer in the past year? Was the refer working correctly until this time? Doug