AERCO BMK 2.0 LN October 2012 - Manual (Page 47)

GF-123
Benchmark 2.0LN Low NOx Boiler
Chapter 3
OMM-0046_0F I nstallation, Operation and Maintenance Manual Operation
PR1 10/17/12 AERCO International Inc.● 100 Oritani Dr. ● Blauvelt, NY 10913. ● Ph: 800-526-0288 Page 47 of 172
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.
Note that the energy input of the boiler is not linearly related to the Air/Fuel Valve position. Refer
to Table 3-8 for the relationship between the energy input and Air/Fuel Valve position for a unit
running on natural gas.