5. Remove igniter assembly.
Allow igniter to cool before removal. Normal operating
temperatures exceed 2000°F.
a. Do not remove igniter from bracket while assembly is in
furnace. Using a 1/4 in. nutdriver, remove screw securing
bracket and igniter assembly to bottom of burner box. The
screw in the bracket is always located toward outside of
burner box. The screw may be hidden by inlet box or inlet
pipe, but can be removed without removing either. After
removing screw, slide igniter and bracket toward outside of
burner box and pull straight out.
The igniter is fragile. DO NOT allow it to hit the side of the
burner box opening while removing or replacing it.
b. Inspect igniter for a white area indicating a crack may be
present. If found, replace igniter.
NOTE:
A small crack cannot be seen on a new igniter. After a
period of operation, a white area will be visible around the crack.
c. If replacement is required, replace igniter on igniter bracket
external to furnace to avoid damage as the silicon portion is
very brittle and will easily crack or shatter.
d. To remove igniter from igniter bracket, remove screw
holding igniter ceramic block to bracket and pull ceramic
block out of bracket.
6. To replace igniter/igniter assembly, reverse items 5a through
5d.
7. Reconnect igniter wire connection.
8. Turn on gas and electrical supplies to furnace.
9. Verify igniter operation by initiating furnace control board
self-test feature or by cycling thermostat.
10. Replace main furnace door.
Step 7—Electrical Controls and Wiring
There may be more than 1 electrical supply to the unit. Check
accessories and cooling unit for additional electrical supplies.
The electrical ground and polarity for 115-v wiring must be
maintained properly. Refer to Fig. 11a or 11b for field wiring
information and to Fig. 16 for unit wiring information.
NOTE:
If the polarity is not correct, the STATUS LED on the
furnace control board will flash rapidly and prevent the furnace
from operating. The control system also requires an earth ground
for proper operation of the furnace control board and flame sensor.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the control. (See Fig. 12.) Any direct shorts of the 24-v wiring
during installation, service, or maintenance will cause this fuse to
blow. If fuse replacement is required, use ONLY a 3 amp fuse. The
control LED will display status code 24 when fuse needs to be
replaced.
With power to the unit disconnected, check all electrical connec-
tions for tightness. Tighten all screws on electrical connections. If
any smoky or burned connections are found, disassemble the
connection, clean all parts, strip wire, and reassemble properly and
securely.
Reconnect electrical supply to unit and observe unit through 1
complete operating cycle for proper operation.
If this furnace is to be operated in an unconditioned space
where the ambient temperatures may be 32°F or lower, freeze
protection measures must be taken. (See Fig. 13.) See
CONDENSATE DRAIN PROTECTION section of Installa-
tion, Start-Up, and Operating Instructions.
Step 8—Checking Heat Tape Operation (If Applicable)
In applications where the ambient temperature around the furnace
is 32°F or lower, freeze protection measures are required. If this
application is where heat tape has been applied, check to ensure it
will operate when low temperatures are present.
NOTE:
Heat tape, when used, should be wrapped around the
condensate drain trap and drain line. There is no need to use heat
tape within the furnace casing. Most heat tapes are temperature
activated, and it is not practical to verify the actual heating of the
tape. Check the following:
1. Check for signs of physical damage to heat tape such as nicks,
cuts, abrasions, gnawing by animals, etc.
Fig. 9—Burner Flame
A89020
;;
;;
BURNER FLAME
BURNER
MANIFOLD
Fig. 10—Gasket on Collector Box
A93081
RTV
PAM
8
