A heat transfer system includes a primary evaporator, a condenser to the primary evaporator by a liquid line and a vapor line, a secondary evaporator connected to the primary evaporator through a sweepage line, and a reservoir system. The reservoir system includes a reservoir, a first flow directional device that restricts fluid from flowing into the reservoir from the primary evaporator, and a second flow directional device that restricts fluid from flowing out of the reservoir through at least one output of the reservoir.