AERCO KC1000 Heater 2002 - Manual (Page 26)

CONTROL PANEL OPERATING PROCEDURES
3-8
(a) Blower relay energizes and turns on
blower.
(b) Air/Fuel Valve rotates to the full-open
purge position and closes purge position
switch. The dial on the Air/Fuel Valve
(Figure 3-4) will read 100 to indicate that
the valve is full-open (100%).
(c) The
FIRE R ATE bargraph will show
100%.
STEPPER
MOTOR
DETAIL "A"
DIAL
(DETAIL “A”)
100
BLOWER BURNER
Figure 3-4.
Air/Fuel Valve In Purge Position
4. Next, the blower proof switch (Figure 3-5)
closes and the display will show Purging
and
indicate the elapsed time of the purge cycle
in seconds. The normal (default) time for the
purge cycle is 7 seconds.
154
155
AIR/FUEL VALVE
BLOWER PROOF
SWITCH
TO FRAME
HARNESS
Figure 3-5.
Blower Proof Switch
5. Upon completion of the purge cycle, the
Control Box initiates an ignition cycle and the
following events occur:
(a) The Air/Fuel Valve rotates to the low-fire
ignition position and closes the ignition
switch. The dial on the Air/Fuel Valve
(Figure 3-6) will read between 25 and 35
to indicate that the valve is in the low-
fire position.
(b) The igniter relay is activated and pro-
vides ignition spark.
(c) The gas Safety Shut Off Valve (SSOV)
is energized (opened) allowing gas to
flow into the Air/Fuel Valve.
6. Up to 7 seconds will be allowed for ignition to
be detected. The igniter relay will be turned
off one second after flame is detected.
7. After 2 seconds of continuous flame, Flame
Proven
will be displayed and the flame
strength will be indicated. After 5 seconds,
the current date and time will be displayed in
place of the flame strength.