AERCO BMK 2.0 LN Natural Gas (SN G-11-1861 and above) - Manual (Page 46)

Chapter 3
Benchmark 2.0LN Low NOx Boiler
GF-123
Operation Installation, Operation and Maintenance Manual OMM-0046_0E
Page 46 of 170 AERCO International Inc.● 100 Oritani Dr. ● Blauvelt, NY 10913. ● Ph: 800-526-0288 PR1 08/20/12
25
TO BLOWER
AIR IN
DIAL
(DETAIL “A”)
STEPPER
MOTOR
DETAIL “A”
Figure 3-6: Air/Fuel Valve In Ignition Position
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.
8. With the unit firing properly, it will be controlled by the temperature controller circuitry. The
boiler’s VALVE POSITION will be continuously displayed on the front panel bargraph.
Once the demand for heat has been satisfied, the Control Box will turn off the dual SSOV gas
valves. The blower relay will be deactivated and the Air/Fuel Valve will be closed. Standby will
be displayed.
3.10 START/STOP LEVELS
The start and stop levels are the Air/Fuel Valve positions (% open) that start and stop the unit,
based on load. These levels are Factory preset as follows:
Natural Gas:
• Start Level: 22%
• Stop Level: 18%
Propane:
• Start Level: 24%
• Stop Level: 20%
Normally, these settings should not require adjustment.