SERVICE AND TECHNICAL SUPPORT MANUAL
Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
26
440 04 4201 03
Figure 9
Burner Assembly
B
URNER
A
SSY
F
LAME
S
ENSOR
(
B
ELOW
B
URNER)
F
LAME
R
OLL
−
OUT
S
WITCH
B
URNER
S
UPT.
A
SSY
L11F064
Representative drawing only, some models may vary in appearance.
Figure 10
Igniter Position
−
Top View
A11405
2-1/2-in.
(64.4)
1-1/4-in.
(31.8)
9. Attach the wires to the roll-out switches.
10. Align the burner assembly with the openings in the
primary cell inlet panel and attach the burner assembly to
the cell panel.
11. Connect the wire for the flame sensor
12. Connect the wire for the Hot Surface Igniter.
NOTE
: Use propane-resistant pipe dope to prevent leaks. Do
not use Teflon tape.
13. Install the gas pipe to the gas valve.
!
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.
14. Check for gas leaks with a soap and water solution.
15. Turn gas on at electric switch on gas valve and at
external shut-off or meter
Figure 11
Igniter Position
−
Side View
L12F041
2
ï
in.
2.5 mm
3/8
ï
in.
3/16
ï
in.
+0.8
ï
1.5 mm
50 mm
9.6 mm
4.6 mm
1/10
ï
in.
+ 1/32
ï
1/16
ï
in.
16. Turn power on at external disconnect, fuse or circuit
breaker.
17. Run the furnace through two complete heating cycles to
check for proper operation
18. Install outer door when complete.
Servicing Hot Surface Igniter
The igniter does
NOT
require annual inspection. Check igniter
resistance before removal. Refer to
.
1. Turn off gas and electrical supplies to furnace.
2. Remove control door.
3. Disconnect igniter wire connection.
4. Check igniter resistance. Igniter resistance is affected by
temperature. Only check resistance when the igniter is at
room temperature.
a. Using an ohm meter, check resistance across both
igniter leads in connector.
b. Cold reading should be between 40 ohms and 70 ohms.
Resistance reading will increase as igniter temperature
increases.
5. Remove igniter assembly.
a. Using a 1/4
−
in. driver, remove the two screws securing
the igniter mounting bracket to the burner assembly.
(See
)
b. Carefully withdraw the igniter and bracket assembly
through the front of the burner assembly without striking
the igniter on surrounding parts.
c. Inspect igniter for signs of damage or failure.
d. If replacement is required, remove the screw that
secures the igniter on igniter bracket and remove the
igniter.
6. To replace igniter and bracket assembly, reverse items
5a through 5e.
7. Reconnect igniter harness to the igniter, dressing the
igniter wires to ensure there is no tension on the igniter
itself. (See