Quote Originally Posted by JayBP View Post
I read something about someone using both just in case their thermostat malfunctioned. I don't remember the section it was posted it, but it was on here. I think they plugged the dimmer into the thermostat. I forget the details.
You would not use a rheostat as a backup unit. You can use an on/off type of thermostat (Ranco or Johnson) as a backup for another thermostat. Set the backup unit to a temp a few degrees higher than the main unit. If the main one malfunctions then the backup will keep it from frying your animals.