Operation of the Defrost System (DEFR306 and standard on 7900/7901 models)

A Defrost System is used to maintain operational temperature below 5ºC. When the chamber temperature is below 4.5ºC, the defrost system is enabled automatically. The Info icon button will appear on the status bar indicating that Defrost is enabled and humidity control is "off". However, if a DRYR301 accessory is installed on the unit, humidity will still control and be active. When the chamber temperature is above 4.5ºC (except during a defrost cycle), the defrost system is disabled automatically.

When the defrost system is enabled (below 4.5ºC), a defrost cycle will occur once every 12 hours (DEFR306) or every 96 hours (7900/7901) and lasts for about 20 minutes. During the defrost cycle, the chamber temperature will increase several degrees above setpoint to melt any ice that has formed on the evaporator. This temperature 'spike' is normal and assures long-term operation.