The Power Control Mode is a feature on the G30 is a feature that was added so that the heating can be controlled when a user wants to distil spirit. This can be done with the G30 with the additional attachment of of the Copper Dome and Alembic Condenser attachments.

As distilling is only possible in the G30 (the Copper Dome attachment can only fit the G30) then the Power Control Mode was not included as a manual feature on the G40 or G70. 

This is something we are looking into as we develop the distilling products range and compatibility with the Grainfather brewing units.