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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
appliances, the venting system is likely to be too large to
properly vent the remaining attached appliances.
Conduct the following test while each appliance is operating
and the other 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.
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 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 burners have 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, widows, 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 problem.
507332-02G / 31-5000663
WARNING
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 2223.1.
Gas Piping
If a flexible gas connector is required or allowed by
the authority that has jurisdiction, black iron pipe shall
be installed at the gas valve and extend outside the
furnace cabinet. The flexible connector can then be
added between the black iron pipe and the gas supply
line.
Gas Supply
1.
This unit is shipped standard for left or right side
installation of gas piping (or top entry in horizontal
applications). Connect the gas supply to the piping
assembly.
2.
When connecting the gas supply piping, consider
factors such as length of run, number of fittings, and
furnace rating to avoid excessive pressure drop.
Table 10 lists recommended pipe sizes for typical
applications.
3.
The gas piping must not run in or through air ducts,
clothes chutes, gas vents or chimneys, dumb waiters,
or elevator shafts.
4.
The piping should be sloped 1/4 inch (6.4 mm) per
15 feet (4.57 m) upward toward the meter from the
furnace. The piping must be supported at proper
intervals [every 8 to 10 feet (2.44 to 3.01 m)] with
suitable hangers or straps. Install a drip leg in vertical
pipe runs to the unit.
5.
A 1/8" N.P.T. plugged tap or pressure post is located
on the gas valve to facilitate test gauge connection.
See Figure 19.
6.
In some localities, codes may require the installation
of a manual main shut off valve and union (furnished
by the installer) external to the unit. The union must be
of the ground joint type.
Compounds used on threaded joints of gas piping must
be resistant to the actions of liquified petroleum gases.
NOTE: If emergency shutoff is necessary, shut off the
main manual gas valve and disconnect main power to the
furnace. The installer should properly label these devices.
Issue 2209
CAUTION
IMPORTANT
Page 19 of 35
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