A lower concentration of methanol than contained in a standard EFOY Fuel Cartridge, EFOY Service Fluid is used as a priming fluid when starting a new EFOY unit for the first time.
It is also used when re-starting units which have not been used in a while - say, if the units is only used seasonally, or only for occasional trips.
The EFOY Operating Panel will typically display an Error 31 when the unit's prime has evaporated, and Service Fluid needs to be added.