8
Combustion control
There is no flue damper in the BIS ULTRA. As is common with air tight stoves, the combustion air
damper controls the air entering the firebox. This allows more precise control of the fire The
combustion air damper knob is located below the left door. It is opened when moved completely to
the left. This control should be in the closed position when the fireplace is not in use. This will
minimize air leakage up the chimney. The combustion air control should be opened before opening
the doors to minimize the possibility
of back draft coming into the room.
Figure 1
Accelerated combustion
The maximum heat output for the BIS ULTRA is achieved
by burning with the doors closed and the combustion air
damper opened. By this method, the BIS ULTRA can
produce up to 60,000 BTU of heat per hour. However, it
will be necessary to reload with wood every one or two
hours. This is the least efficient method of burning the
BIS ULTRA.
Use caution when firing with the combustion air control wide open. Only burn cordwood in this
manner. Small dry pieces of softwood and construction scraps will burn very intensely using this
method and may damage the firebox.
