AERCO BMK 2.0 LN Natural Gas (SN G-11-1861 and above) - Manual (Page 58)

Chapter 4
Benchmark 2.0LN Low NOx Boiler
GF-123
Initial Start-Up Installation, Operation and Maintenance Manual OMM-0046_0E
Page 58 of 170 AERCO International Inc.● 100 Oritani Dr. ● Blauvelt, NY 10913. ● Ph: 800-526-0288 PR1 08/20/12
IMPORTANT
The unit is shipped from the factory set up for either Natural
Gas or Propane as specified by the Style No. on the Sales
Order.
Since the required gas pressures and oxygen (O
2
) levels for
Propane differ from those required for Natural Gas, the Pro-
pane Combustion Calibration procedures are repeated in
paragraph 4.5.
4.5 PROPANE COMBUSTION CALIBRATION
The Benchmark 2.0LN Boiler is combustion calibrated at the factory prior to shipping. However,
recalibration as part of initial start-up is necessary due to changes in the local altitude, gas BTU
content, gas supply piping and supply regulators. Factory Test Data sheets are shipped with
each unit. These sheets must be filled out and returned to AERCO for proper Warranty
Validation.
Prior to starting these procedures, ensure that the Benchmark 2.0LN has been set up as
specified in paragraphs 4.2 through 4.2.3.
It is important to perform the following procedure as outlined. This will keep readjustments to a
minimum and provide optimum performance.
1. Open the water supply and return valves to the unit and ensure that the system pumps are
running.
2. Open the propane supply valve(s) to the unit.
3. Set the control panel ON/OFF switch to the OFF position.
4. Turn on external AC power to the unit. The display will show LOSS OF POWER and the
time and date.
5. Set the unit to the Manual Mode by pressing the AUTO/MAN key. A flashing Manual Valve
Position message will be displayed with the present rate in %. Also, the MANUAL LED will
light.
6.
Adjust the valve position to 0% by pressing the ▼ arrow key.
7. Ensure that the leak detection ball valve (Figure 4-1) down-stream of the SSOV is open.
8. Set the ON/OFF switch to the ON position.
9. Change the valv
e position to 29% using the ▲ arrow key. The unit should begin its start
sequence and fire.
10. Next, verify that the gas pressure downstream of the SSOV is 2.3” W.C. for both FM and IRI
gas trains. If gas pressure adjustment is required, remove the brass hex nut on the SSOV
actuator (IRI gas train) containing the gas pressure regulator (Figure 4-3). Make gas
regulator adjustments using a flat-tip screwdriver to obtain 2.3” W.C.
11. Raise the valve position to 100% and verify that the gas pressure downstream of the SSOV
remains at 2.3” W.C. Readjust pressure if necessary.
12. With the valve position at 100%, insert the combustion analyzer probe into the flue probe
opening and allow enough time for the combustion analyzer to stabilize.
13. Compare the measured oxygen % level to the range shown below. Also, ensure that the
carbon monoxide (CO) and nitrogen oxide (NOx) readings do not exceed the values shown.