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54
CLEANFIRE OUTDOOR FURNACE • OWNER'S MANUAL
Ash
Flow
Blocked
© 2019 Central Boiler
INCORRECT
(Blocked Flow)
Are the air inlets plugged?
Primary combustion air is provided through the combustion air inlets in
the firebox. If the air inlets are restricted or plugged, the furnace will not
operate correctly. If it appears the combustion air inlets are plugged or
restricted, refer to the Maintenance Sections for the Combustion Air Tubes
and Air Tube and Refractory. If after cleaning each combustion air inlet, air
flow is still blocked, inspect the primary combustion air elbow. Refer to the
Maintenance Section for Primary Air Elbow.
NOTE: If there is creosote buildup in the primary air elbow, it is caused by operating
the furnace incorrectly. It is important to follow the recommended operation and
maintenance procedures (see Adding Wood section).
Is there creosote and/or ash inside the airbox?
Creosote, ash, or even coals in the airbox is an indication that the outdoor
furnace has not been maintained and/or operated properly. Especially
important to the operation and efficiency of the outdoor furnace is
unrestricted air flow throughout the entire system. Refer to Adding Wood for
a detailed explanation of how to operate and maintain your CleanFire.
One or more combustion air inlets are covered - If the level of coals and
ash in the firebox is allowed to accumulate over the combustion air inlets,
normal air flow can be blocked and could force coals and ash back into the
airbox. Remove enough ash so the combustion air inlets are not covered.
Review the Adding Wood section for more information.