No, the primary firing heater rotates every 24 hours or 8 hours of combustion time. This ensures even usage of the heaters.
Refer to system controller installation manual for more details, located at http://support.noritz.com/technical-literature.php
A device used to link two or more heaters together so they operate as one system (up to 24 units.)
- Models: All commercial units and units compatible with a system controller.