Product Manual

HeatPack Furnace Installation and Operation Manual
47
10.3.3 Firing each new hot load
Place the new load of wood on and behind the charcoal, and not too close to the glass.
Close the door and open the air control damper. Leave the air control damper open until
the firebox is full of flames, the wood has charred to black and its edges are glowing red.
Firing each load of wood hot accomplishes a few things:
 Drives the surface moisture from the wood,
 Creates a layer of char on the wood, which slows down its release of smoke,
 Heats the firebox components so they reflect heat back to the fire, and
 Heat the chimney so it can produce strong, steady draft for the rest of the cycle.
DO NOT LEAVE THE FURNACE UNATTENDED WHILE A NEW LOAD IS BEING
FIRED HOT.
DO NOT OVERFIRE.
When you burn a new load of wood hot to heat up the wood, the furnace and the chimney,
the result will be a surge of heat from the furnace. This heat surge is welcome when the
room temperature is a little lower than desirable, but not welcome if the space is already
warm. Therefore, allow each load of wood to burn down so that the space begins to cool
off a little before loading.
10.3.4 Control of the air supply
Once the firewood, firebox and chimney are hot, you can close the air supply for a steady
burn.
If the flames get very small and almost disappear when you close the air control damper,
you have closed it too early, or your firewood is more humid than it should be. With good
fuel and correct air control use, the flames should slow down, but should stay large and
steady, even as the air supply is closed.
When the furnace is using a thermostat, it is the thermostat that controls the air control
damper, if the air control damper is in the closed position. When the thermostat calls
for heat, the air control damper opens and the combustion is stirred up. When the furnace
gets hot enough, the blower motor is activated.