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507388-01
Issue 1732
Removal of Unit from Common Venting System
When an existing furnace is removed from a common
venting system serving other appliances, the venting
system is likely to be too large to properly vent the
remaining attached appliances. The following test
should be conducted with each appliance while the other
appliances connected to the common venting system are
not in operation.
1. Seal any unused openings in the common venting
system.
2.
Visually inspect the 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
windows between the space in which the appliances
remaining connected to the common venting system
are located and other spaces in the building. Turn on
clothes dryers and any appliance not connected to the
common venting system. Turn on 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. Following the lighting instructions, place the unit being
inspected in operation. Adjust the thermostat so the
appliance will operate continuously.
5. Test for spillage at the draft control relief opening after
5 minutes of main burner operation. Use the flame of
a match or candle.
6. Follow the preceding steps for each appliance
connected to the common venting system.
7. After it has been determined that each appliance
remaining 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 their previous
condition of use.
8. If improper venting is observed during any of the above
tests, the common venting system must be corrected.
See National Fuel Gas Code, ANSI Z223.1 (latest
edition) to correct improper operation of common
venting system.
Gas Connections
The gas line to the unit should be adequately sized to
prevent undue pressure drop and should never be smaller
than the manual valve used. Consult the local utility or
National Fuel Gas Code for complete details on special
requirements in sizing gas piping.
The units supplied for operation with natural gas contain
a gas regulator which must be operated with inlet gas
pressures specified on the rating plate. If gas line pressure
exceeds this figure, an additional high pressure regulator
must be installed to reduce this pressure.
Units for operation with propane must be converted with a
kit supplied by the manufacturer and require for operation
an inlet pressure of 11” W.C. minimum and 13” W.C.
maximum. A regulator is also required on the propane tank.
If local codes allow use of a flexible gas connector, a new
listed connector must be used. Do not use a connector
which has previously serviced another gas appliance.
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.
CAUTION
Compounds used on threaded joints of gas piping must
be resistant to the actions of liquified petroleum gases.
IMPORTANT
Never use a flame to check for gas leaks. Explosion
causing injury or death may occur.
CAUTION
The furnace must be isolated from the gas supply piping
system by closing the individual manual shutoff valve
during any pressure testing of gas supply piping system
at test pressures equal to or less than 1/2 psig or 14”
W.C. If the piping system is to be tested at pressures in
excess of 1/2 psig, the furnace and its individual shutoff
valve must be disconnected from the gas supply piping
system. The gas valve supplied with this furnace is
rated at 1/2 psig. Any higher pressure may rupture the
pressure regulator diaphragm which will cause over-
firing of the burners and improper burner operation.
This action may produce a high concentration of carbon
monoxide which can result in asphyxiation.
WARNING
A manual shutoff valve must be located outside the unit.
The use of a union located upstream of the controls is
recommended, between the controls, and the manual
shutoff valve. This will facilitate removal of controls and
manifold. See Figure 3 for recommended placement of the
union.
