Herein disclosed are systems and methods related to delivery systems using solid source chemical fill vessels. The delivery system can include a vapor deposition reactor, two or more fill vessels, of which one of more can be remote from the vapor deposition reactor. Each fill vessel is configured to hold solid source chemical reactant therein. An interconnect line or conduit can fluidly connect the vapor deposition reactor with one or more of the fill vessels. A line heater can heat at least a portion of the interconnect line to at least a minimum line temperature.