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13. The vent pipe shall not be connected to a chimney vent
serving a solid fuel appliance or any mechanical draft
system.
14. All unused chimney openings should be closed.
15. All vent pipe run through unconditioned areas or out
side shall be constructed of factory-built chimney sec
tions. See figure 9.
16. Where condensation of vent gas is apparent, the vent
should be repaired or replaced. Accumulation of con
densation in the vent is unacceptable.
17. Vent connectors serving this appliance shall not be
connected into any portion of mechanical draft sys
tems operating under positive pressure.
18. Keep the area around the vent terminal free of snow,
ice and debris.
Factory‐Built Chimney
BAROMETRIC
CONTROL*
(IN EITHER
LOCATION)
DRAIN FOR
CONDENSATE
FACTORY
BUILT
CHIMNEY
Figure 9
horizontal ap
plication shown
*Barometric draft control may be installed in either vertical or
horizontal section of flue pipe no less than 12” and no more than
18” from furnace flue outlet.
Removal of Unit from Common Venting System
In the event that an existing furnace is removed from a
venting system commonly run with separate appliances,
the venting system is likely to be too large to properly vent
the remaining attached appliances. The following test
should be conducted while each appliance is in operation
and the other appliances not in operation remain con
nected to the common venting system. If venting system
has been installed improperly, the system must be cor
rected as outlined in the previous section.
1 - Seal any unused openings in the common venting
system.
2 - Visually inspect venting system for proper size and
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion or other deficiencies
which could cause an unsafe condition.
3 - Insofar as is practical, close all building doors and win
dows and all doors between the space in which the ap
pliances remaining connected to the common venting
system are located and other spaces of the building.
Turn on clothes dryers and any appliances not con
nected to the common venting system. Turn on any
exhaust fans, such as range hoods and bathroom ex
hausts, so they will operate at maximum speed. Do
not operate a summer exhaust fan. Close fireplace
dampers.
4 - Following the lighting instruction on the unit, place the
appliance being inspected in operation. Adjust ther
mostat so appliance will operate continuously.
5 - Test for spillage using a draft gauge.
6 - After it has been determined that each appliance re
maining connected to the common venting system
properly vents when tested as outlined above, return
doors, windows, exhaust fans, fireplace dampers and
any other fuel burning appliance to its previous condi
tion of use.
7 - If improper venting is observed during any of the
above tests, the common venting system must be
corrected.
Flue Connections
IMPORTANT
When flue pipe is installed at less than minimum
clearance listed in tables 2 and 3, radiation shields
must be installed. See figure 10.
Use 24 gauge or heavier galvanized smoke pipe and fit
tings to connect furnace to vent. Maintain rise of at least
one inch per foot. Connect flue pipe to chimney using the
least number of elbows and angles possible. Flue pipe or
vent connector must be inserted into but not beyond the
outside wall of the chimney flue. No reduction in diameter
of flue pipe is acceptable. It is best to have flue pipe as
short and direct as possible.
Where two or more appliances vent into a common flue,
the area of the common flue should be at least equal to the
area of the largest flue or vent connector, plus 50% of the
area of any additional flues or vent connectors. Install
barometric draft control (provided) and flue pipe according
to instructions packed with control.
Inspect flue pipe annually. Clean soot or ash from flue pipe,
if necessary. If pipe is rusted, replace.
