Evaporator system used for the production of maple syrup. The evaporator system includes at least one receptacle, a combustion chamber, an evacuation port and an air supply system. The evaporator system also includes a door assembly being configured for removably mounting onto a corresponding support frame of the evaporator system, and being operable between an opened configuration for allowing access to the combustion chamber and to be able to selectively feed biomass into the combustion chamber via the inlet thereof, and a closed configuration for preventing access to and closing off the inlet of the combustion chamber, the door assembly being provided with at least one aeration passage extending between an outer portion of the door assembly and an inner portion therefor, for providing a supply of secondary air to the combustion chamber via said at least one aeration passage of the door assembly when operated in the closed configuration.