Found drainpan full causing unit to shut off on float switch - removed all water from pan - cycled unit to check operation - checked operation of unit drain line, unit trap, unit condensate pump - noticed that condensate pump operates only when the pump is almost totally full leaving a period of time where water has an opportunity to leak out between the seam of the pump and the condensate tray. Did not find any damp insulation or any evidence of a leak in the furnace. Did not find any evidence of a cracked drain pan. Ordered replacement low profile condensate pump - will call with pricing and availability.