AERCO BMK 1.5 LN October 2012 - Manual (Page 42)

CHAPTER 3
OPERATION
Page 42 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Benchmark 1.5LN Low NOx Boiler
Installation, Operation and Maintenance Manual
GF-120
OMM-0041 0E
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.
The DEMAND LED status indicator will light. 1.
The unit checks to ensure that the Proof of Closure (POC) switch in the downstream 2.
Safety Shut-Off Valve (SSOV) is closed. See Figure 3-3 for SSOV location.
With all required safety device switches closed, a purge cycle will be initiated and the 3.
following events will occur:
a. The Blower relay energizes and turns on blower.
b. The 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 it is
full-open (100%).
c. The VALVE POSITION bargraph will show 100%.
Figure 3-3: SSOV Location
TO
AIR/FUEL
VALVE
GAS
INLET
SSOV
MANUAL GAS
SHUT-OFF
VALVE