507714-01
Page 15 of 52
Issue 1716
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation could result in carbon monoxide
poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation.
DANGER
1. Seal any unused openings in the common venting
system.
2. Inspect the venting system for proper size and
horizontal pitch. Determine that there is no blockage,
restriction, leakage, corrosion, or other deficiencies
which could cause an unsafe condition.
3. Close all building doors and windows and all doors
between the space in which the appliances remaining
connected to the common venting system are located
and other spaces of the building. Turn ON clothes
dryers and any appliances not connected to the
common venting system. Turn ON any exhaust fans,
such as range hoods and bathroom exhausts, so they
will operate at maximum speed. Do not operate a
summer exhaust fan. Close fireplace dampers.
4. Follow the lighting instructions. Turn ON the appliance
that is being inspected. Adjust the thermostat so that
the appliance operates continuously.
5. After the main burner has operated for 5 minutes, test
for leaks of flue gases at the draft hood relief opening.
Use the flame of a match or candle.
6. After determining that each appliance connected to
the common venting system is venting properly, (step
3) return all doors, windows, exhaust fans, fireplace
dampers, and any other gas burning appliances to
their previous mode of operation.
7. If a venting problem is found during any of the
preceding tests, the common venting system must be
modified to correct the problems.
Resize the common venting system to the minimum vent
pipe size determined by using the appropriate tables in
Appendix G. These are in the current standards of the
National Fuel Gas Code ANSI Z223.1.
Figure 21.
1. In areas where piping penetrates joist or interior walls,
hole must be large enough to allow clearance on all
sides of pipe through center of hole using a hanger.
2. When furnace is installed in a residence where unit
is shut down for an extended period of time, such
as a vacation home, make provisions for draining
condensate collection trap and lines.
Exhaust Piping
Route piping to outside of structure. Continue with
installation following instructions given in piping termination
section.
Do not discharge exhaust into an existing stack or
stack that also serves another gas appliance. If vertical
discharge through an existing unused stack is required,
insert PVC pipe inside the stack until the end is even
with the top or outlet end of the metal stack.
CAUTION
The exhaust vent pipe operates under positive pressure
and must be completely sealed to prevent leakage of
combustion products into the living space.
CAUTION
