Page 26
Removal of the Furnace from Common Vent
In the event that an existing furnace is removed from a
venting system commonly run with separate gas applianc-
es, the venting system is likely to be too large to properly
vent the remaining attached appliances. Conduct the fol-
lowing test while each appliance is operating and the oth-
er appliances (which are not operating) remain connected
to the common venting system. If the venting system has
been installed improperly, you must correct the system as
indicated in the general venting requirements section.
WARNING
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:
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
deciencies 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 replace
dampers 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 replace
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 ue gases at the draft hood relief
opening. Use the ame 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, widows, exhaust fans,
replace 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 modied to correct the problem.
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. Exhaust Piping (Figures 23 and 24)
Route piping to outside of structure. Continue with
installation following instructions given in piping
termination section.
Exhaust Piping (Figures 23 and 24)
Route piping to outside of structure. Continue with instal-
lation following instructions given in piping termination
section.
WARNING
Carbon Monoxide Poisoning Hazard
Cutting or altering exhaust or air intake pipes, which
are located in the blower compartment, could result
in Carbon Monoxide Poisoning or Death.
CAUTION
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.
To Next Page
Loading...
Need help?
General