13
1. Route gas piping to unit so that it does not interfere
with the removal of access panels. Support and
align piping to prevent strains or misalignment of the
manifold assembly.
2. All units are furnished with standard female 1/2” NPT
pipe connections. The size of the gas supply piping
to the unit must be based on length of run, number
of units on the system, gas characteristics, BTU
requirement and available supply pressure. All piping
must be done in accordance with local codes or, in the
absence of local codes, with the latest edition of the
National Fuel Gas Code
ANSI Z223.1/NFPA 54.
notE: t
HE
GaS
connEctIon
SIZE
at
tHE
UnIt
doES
not
EStablISH
tHE
SIZE
of
tHE
SUPPly
lInE
.
3. These units are designed for either natural or
propane (LP) gas and are specifically constructed at
the factory for only one of these fuels. The fuels are
NOT interchangeable. However, the furnace can be
converted in the field from natural gas to LP gas with
the appropriate factory kit (see unit Technical Manual
for the appropriate kit). Only a qualified contractor,
experienced with natural and propane gas systems,
should attempt conversion. Kit instructions must
be followed closely to assure safe and reliable unit
operation.
4. With all units on a common line operating under
full fire, natural gas main supply pressure should
be adjusted to approximately 7.0” w.c., measured
at the unit gas valve. If the gas pressure at the
unit is greater than 10.0” w.c., the contractor must
furnish and install an external type positive shut off
service pressure regulator. The unit will not function
satisfactorily if supply gas pressure is less than 5.0”
w.c. or greater than 10.0” w.c..
notE: a
MInIMUM
HoRIZontal
dIStancE
of
48”
bEtWEEn
tHE
REGUlatoR
and
tHE
fURnacE
flUE
dIScHaRGE
IS
REqUIREd
.
5. With all units on a common line operating under
full LP gas main supply pressure should be at least
11.0” w.c. and must be no greater than 13.0” w.c.,
measured at the unit gas valve. Unit will not function
satisfactorily if supply gas pressure is less than 11.0”
w.c. or greater than 13.0” w.c..
6. All pipe connections should be sealed with a pipe
thread compound, which is resistant to the fuel used
with the furnace. A soapy water solution should be
used to check all joints for leaks. A tap is located
on the entering side of the gas valve for test gauge
connection to measure supply (main) gas pressure.
Another tap is provided on the manifold side of the
gas valve for checking manifold pressure.
WARNING
t
HIS
UnIt
and
ItS
IndIvIdUal
SHUtoff
valvE
MUSt
bE
dISconnEctEd
fRoM
tHE
GaS
SUPPly
SyStEM
dURInG
any
PRESSURE
tEStInG
of
tHat
SyStEM
at
tESt
PRESSURES
In
ExcESS
of
½ PSIG (13.8”
W
.
c
.).
CAUTION
t
HIS
UnIt
MUSt
bE
ISolatEd
fRoM
tHE
GaS
SUPPly
PIPInG
SyStEM
by
cloSInG
ItS
IndIvIdUal
ManUal
SHUtoff
valvE
dURInG
any
PRESSURE
tEStInG
EqUal
to
oR
lESS
tHan
½ PSIG.
7.
There must be no obstruction to prevent the flow of
combustion and ventilating air. A vent stack is not
required and must never be used. The power venter
will supply an adequate amount of combustion air
as long as the air passageways are kept free of any
obstructions and the recommended external unit
clearances are maintained.
CIRCULATING AIR AND FILTERS
d
UctWoRk
The supply duct from the unit through a wall may be
installed without clearance. However, minimum unit
clearances must be maintained (see “Clearances” section).
The supply duct should be provided with an access panel
large enough to inspect the air chamber downstream of
the heat exchanger. A cover should be tightly attached to
prevent air leaks.
Ductwork dimensions are shown in the roof curb
installation manual.
If desired, supply and return duct connections to the unit
may be made with flexible connections to reduce possible
unit operating sound transmission.
CONDENSATE DRAIN CONNECTION
c
ondEnSatE
d
RaIn
c
onnEctIon
A 3/4” female NPT drain connection is supplied on the
end of the unit and bottom of the drain pan for condensate
piping. An external trap must be installed for proper
condensate drainage. Hand tighten drain fitting to the drain
connection.
DRAIN
CONNECTION
UNIT
2" MINIMUM
FLEXIBLE
TUBING-HOSE
OR PIPE
3" MINIMUM
A POSITIVE LIQUID
SEAL IS REQUIRED
dRaIn
connEctIon
