8 start sequence, Control panel operating procedures – AERCO KC1000 Boiler equipped with C-More version 3.04 User Manual
Page 30

CONTROL PANEL OPERATING PROCEDURES
3.8. START SEQUENCE
When the Control Box ON/OFF switch is set to 
the ON position, it checks all pre-purge safety 
switches to ensure they are closed. These 
switches include: 
• Safety Shut-Off Valve Proof of Closure 
(POC) switch
• Low Water Level switch 
• High 
Water
Temperature
switch
• High Gas Pressure switch 
• Low Gas Pressure switch 
If all of the above switches are closed, the 
READY
light above the ON/OFF switch will light
and the unit will be in the Standby mode. 
 
When there is a demand for heat, the following 
events will occur: 
 
NOTE:
If any of the Pre-Purge safety device switches 
are open, the appropriate fault message will be 
displayed. Also, the appropriate fault messages 
will be displayed throughout the start sequence, 
if the required conditions are not observed. 
1. The DEMAND LED status indicator will light.
2. The unit checks to ensure that the proof of
closure switch in the Safety Shut-Off Valve 
(SSOV) is closed (Figure 3-3). 
Figure 3-3.
Safety Shut-Off Valve
3. With all required safety switches closed, a
purge cycle will be initiated and the following 
events will occur: 
(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%). 
STEPPER
MOTOR
DETAIL "A"
DIAL
(DETAIL “A”)
100
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. 
3-8
