User Manual

RECON Water Heaters Installation, Operation & Maintenance Manual
CHAPTER 4 – INITIAL START-UP
Page 62 of 178 AERCO International, Inc.  100 Oritani Dr.  Blauvelt, NY 10913 OMM-0103_0A
PRI: 10/28/2014 Phone: [phone] GF-147
NATURAL GAS Combustion Calibration – Continued
NOTE
If NOx readings exceed the target values shown (<20 ppm), increase the O
2
level up to 25% higher than the listed calibration range shown in the table.
Record the increased O
2
value on the Combustion Calibration sheet.
Combustion Calibration Readings
Valve
Position
Oxygen (O
2
) %
Nitrogen
Oxide (NOx)
Carbon
Monoxide (CO)
Flame
µA
80% 6.5% ± 0.2% <20 ppm <100 ppm
> 6
60% 7.5% ± 0.2% <20 ppm <100 ppm
> 6
50% 8.0% ± 0.2% <20 ppm <100 ppm
> 6
40% 8.0% ± 0.2% <20 ppm <100 ppm
> 6
30% 8.3% ± 0.2% <20 ppm <100 ppm
> 5
20% 8.0% ± 0.2% <20 ppm <100 ppm
> 4
16% 5.8% ± 0.2% <20 ppm <100 ppm
> 4
23. If the oxygen level at the 16% valve position (RECON 500) or 20% valve position (RECON
1000) is too high and the Blower voltage is at the minimum value, you can adjust the idle
screw (TAC valve), which is recessed in the top of the Air/Fuel Valve (Figure 4-5). Rotate the
screw 1/2 turn clockwise (CW) to add fuel and reduce the O
2
to the specified level.
Recalibration MUST be performed again from 60% down to 16% after making a change to the
idle screw (TAC valve).
Figure 4-5. TAC Valve Adjust (Idle Screw)
This completes the Natural Gas combustion calibration procedure.


4.3.1 REASSEMBLY AFTER COMBUSTION CALIBRATION
Once the combustion calibration adjustments are properly set, the unit can be reassembled for
service operation.
TAC VALVE
IDLE SCREW
FRONT VIEW – POWER BOX REMOVED FOR CLARITY