Calefactio’s GMP are economical yet rugged, compact and easy to use fluid feeders for small closed-loop systems. Their function is to automatically supply pressurized water or a water/glycol mixture to a closed-loop space heating, chilled water, snowmelt, radiant heating or process control system, to ensure that minimum system pressure levels are maintained. The optional remote alarm panel kit will provide an audible and visual indication of a system leak..