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HEATING SECTION COMPONENTS
FIGURE 15
IGNITION
WIRE
J15 P15
J29
B6
COMBUSTION
AIR INDUCER
GV1 GAS
VALVE
S18 BLOWER
PROVING SWITCH
S10
PRIMARY
LIMIT
SWITCH
A3
IGNITION
CONTROL
SENSOR
WIRE
J19
P19
S47 ROLLOUT
SWITCH
D
-GAS HEAT COMPONENTS
See SPECIFICATIONS tables or unit nameplate for Btuh
capacities. Units are equipped with two identical gas heat
sections (gas heat section one and gas heat section two)
Flexible pipe will feed supply gas to both sections. If for
service the flexible connection must broken, hand tighten
then turn additional 1/4” with a wrench for metal to metal
seal (do not overtighten).
NOTE - Do not use thread sealing compound on flex pipe
flare connections.
1-Control Box Components
A3, A12, A55
WARNING
Shock hazard. Spark related compo
nents contain high voltage which can
cause personal injury or death. Discon
nect power before servicing. Control is
not field repairable. Unsafe operation
will result. If control is inoperable, sim
ply replace the entire control.
Burner Ignition Control A3, A12
The ignition controls are located in the heat section
areas
below the compressors. The controls are manufactured
UTEC. See table 9 for LED codes.
The ignition control provides three main functions: gas
valve control, ignition and flame sensing. The unit will usu
ally ignite on the first attempt; however, the ignition attempt
sequence provides three trials for ignition before locking
out. The lockout time for the control is 5 minutes. After lock
out, the ignition control automatically resets and provides
three more attempts at ignition. Manual reset after lockout
requires breaking and remaking power to the ignition con
trol. See figure 16 for a normal ignition sequence and figure
17 for the ignition attempt sequence with retrials (nominal
timings given for simplicity). Specific timings for the ignition
controls are shown in figure 18.
TABLE 9
UTEC
LED
Flashes
Indicates
Slow Flash Control ok, no call for heat
Fast Flash Control ok, call for heat present.
Steady Off Internal control fault or no power
Steady On
Failure
Control internal failure
1 Flash Rollout switch open
2 Flashes
Limit open or lockout from to many tries
during a single heat demand
3 Flashes
Pressure switch open with inducer on/
open during 5 minute inducer off time.
4 Flashes
Ignition lockout from no flame detected or
from too many flame losses.
5 Flashes Flame sensed out of sequence
6 Flashes Pressure switch closed with inducer off
7 Flashes Gas valve relay failure
8 Flashes
Lockout due to too many pressure switch
openings during one heat demand
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