INSTALLATION INSTRUCTIONS
Gas Furnace: (F/G)9MAE
440 01 4300 02
27
Specifications subject to change without notice.
GAS PIPING
!
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Never purge a gas line into a combustion chamber. Never test for gas
leaks with an open flame. Use a commercially available soap solution
made specifically for the detection of leaks to check all connections. A
fire or explosion may result causing property damage, personal injury
or loss of life.
!
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Use proper length of pipe to avoid stress on gas control manifold and
a gas leak.
!
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Gas valve inlet and/or inlet pipe must remain capped until gas supply
line is permanently installed to protect the valve from moisture and
debris. Also, install a sediment trap in the gas supply piping at the inlet
to the gas valve.
Gas piping must be installed in accordance with national and
local codes. Refer to current edition of NFGC in the U.S.A.
Refer to current edition of CAN/CSA B149.1 in Canada.
Installations must be made in accordance with all authorities
having jurisdiction. If possible, the gas supply line should be a
separate line running directly from meter to furnace.
NOTE
: Use a back
−
up wrench on the inlet of the gas valve
when connecting the gas line to the gas valve.
NOTICE
In the state of Massachusetts:
1. Gas supply connections MUST be performed by a li-
censed plumber or gas fitter.
2. When flexible connectors are used, the maximum
length shall not exceed 36
−
in. (915 mm).
3. When lever handle type manual equipment shutoff
valves are used, they shall be T
−
handle valves.
4. The use of copper tubing for gas piping is NOT ap-
proved by the state of Massachusetts.
Refer to
Table 10
for recommended gas pipe sizing. Risers
must be used to connect to furnace and to meter. Support all
gas piping with appropriate straps, hangers, etc. Use a
minimum of one hanger every 6 ft. (1.8 M). Joint compound
(pipe dope) should be applied sparingly and only to male
threads of joints. Pipe dope must be resistant to the action of
propane gas.
!
WARNING
FIRE OR EXPLOSION HAZARD
A failure to follow this warning could result in personal injury, death, and/
or property damage.
If local codes allow the use of a flexible gas appliance connector, always
use a new listed connector. Do not use a connector which has previously
served another gas appliance. Black iron pipe shall be installed at the fur-
nace gas control valve and extend a minimum of 2
−
in. (51 mm) outside
the furnace.
!
CAUTION
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in furnace damage.
Connect gas pipe to furnace using a backup wrench to avoid damaging
gas controls and burner misalignment.
Table 10 Maximum Capacity of Pipe
NOMINAL
IRON PIPE
SIZE
IN. (MM)
INTERNAL
DIA.
IN. (MM)
LENGTH OF PIPE
−
FT (M)
10
(3.0)
20
(6.0)
30
(9.1)
40
(12.1)
50
(15.2)
1/2 (13)
0.622
(158)
175
120
97
82
73
3/4 (19)
0.824 (20.9)
360
250
200
170
151
1 (
25)
1.049 (26.6)
680
465
375
320
285
1‐1/4 (32)
1.380 (35.0)
1400
950
770
660
580
1‐1/2 (39)
1.610 (40.9)
2100
1460
1180
990
900
* Cubic ft of gas per hr for gas pressures of 0.5 psig (14-In. W.C.) or less and
a pressure drop of 0.5-In. W.C. (based on a 0.60 specific gravity gas). Ref:
Table 10
above, and 6.2 of NFPA54/ANSI Z223.1-2012.
An accessible manual equipment shutoff valve MUST be
installed external to furnace casing and within 6 ft. (1.8 M) of
furnace.
Install a sediment trap in riser leading to furnace as shown in
Figure 31
. Connect a capped nipple into lower end of tee.
Capped nipple should extend below level of furnace gas
controls. Place a ground joint union between furnace gas
control valve and exterior manual equipment gas shutoff valve.
Figure 31
Typical Gas Pipe Arrangement
L10F030
A 1/8
−
in. (3 mm) NPT plugged tapping, accessible for test
gauge connection, MUST be installed immediately upstream of
gas supply connection to furnace and downstream of manual
equipment shutoff valve.
