Installation and Operation

26D4720
14
MCUF Series Vent-Free Firebox

7. If the duct is the insulated type, push the insulation back
from one end of the duct approximately 2". Figure 19
8. Slip the exposed end of the duct over the starting collar
on the replace.
9. Using the sheet metal screws provided, secure the duct
end to the collar attached to the replace.
10.Nail or screw the combustion air assembly to the surface
of the wall.
 If the wall covering is brick or stone, use appropriate
masonry fasteners. If necessary, splice the duct. Use a
model 403-duct connector to splice duct sections.
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1. Push insulation back approximately 2" from the end of
each duct.
2. Slip each duct over duct connector until an equal length
of connector extends into each duct.
3. Place duct clamp over the end of each duct. Tighten
duct clamp down snuggly.
4. Push insulation back into place and over duct clamp.
FP1907
Duct connector
8/08
Approximately
2”
Figure 19 -
Install Duct Connector 403
Insulation
Duct
Connector
Duct Clamp
Duct
FP1907