Question: What is the actual function of the damper ion the side of the vigilant for.Is there any adjustment or pre selected setting for it, if so what gives the optimum burn. I am looking for a user guide for it also. Thanks for your time Answer: This is not really a damper, rather it is a bypass. What this means is that in one position, it allows the smoke to go straight up the chimney and in the other take a more convoluted path. The idea is that starting and loading should be done with the stove in the open position, and then the bypass should be closed once everything is going well. The stove requires a reasonable draft to operate correctly in the closed or downdraft mode.