NTI INSTALLATION MANUALS

Part 11 - Start-Up

Operation 3 - Adjusting the CO2 at Maximum Gas Flow Rate (High Fan Speed) Set the thermostat at the highest possible setting or draw o the domestic hot water at the maximum water ow rate to create a demand for heat. Note: For only Heating Boiler Applications, open all thermostatic valves present in the CH circuit. Select the TEST Function by pressing and holding the RESET button for 10 seconds. WARNING! When the Test Function is activated the temperature of the water coming out of the boiler may be more than 150°F.

B. Combustion Checking Procedure The order of operations for this procedure must always be respected. Operation 1 - Gas inlet pressure check Loosen screw 1 (Torx 10 - Line Pressure Test Port) and connect a manometer to the port using applicable tubing. Ensure the boiler is powered on. Then enable Test Mode by pressing the RESET button for 10 seconds. The display will show and the icon . The gas line pressure must remain within the range provided in Table 23 for the gas type

4

2

1

and the icon will appear on the display when Test Function is active. The boiler will operate at maximum heating power.

Figure 74 - Gas Valve

Press the button to operate the boiler at the maximum power. The icon will display. Wait 1 minute for the boiler to stabilize before carrying out the combustion analyses. Read the CO2 value (%) and compare it with the values given in the table below:

during all operating conditions. Upon completion of the combustion analysis and adjustment (Operations 2 through 5), remove the pressure gauge and tighten screw 1. Verify and repair any gas leaks. Operation 2 - Combustion Analysis Remove the combustion test port plug as illustrated, and insert a calibrated combustion analyzer.

Natural Gas

LP Gas

Fan Speed Low High

Low High

<175

<175

CO PPM

CO 2 (%) 9.5 - 10.7 The CO2 at minimum gas flow rate (Low Fan Speed) must be set lower than the CO2 reading at maximum gas flow rate (High Fan Speed) by 0.5 to 1.0%. For Example: If CO2 at High = 9.2%, then CO2 at Low must = 8.7% - 8.2% 8.5 - 9.7

Table 32 - Combustion Settings

Figure 75 - Combustion Test Port

ATTENTION!! Obtain all values with the front cover installed.

WARNING

If the CO2 (%) reading di ers from the values given in the table, adjust the gas valve following the instructions below. Otherwise move directly to Operation 4.

Make sure the calibrated combustion analyzer is set to the appropriate gas type. Failure to do so could result in serious personal injury or death. It is required to use a calibrated combustion analyzer to verify Ànal adjustment according to the combustion chart (Table 33). Failure to do so could result in serious personal injury or death. It is very important that the combustion system be set within the recommended CO measurements listed in Table 33. Visually looking at the burner does not determine combustion quality. Failure to measure combustion with a calibrated combustion analyzer and set the throttle within the recommended CO measurements could result in property damage, severe personal injury, or death.

Adjusting the Gas Valve at Maximum Gas Flow Adjust the gas valve by turning setting screw 4 clockwise to increase the CO2 level; counterclockwise to reduce the CO2 level (1 turn adjusts the CO2 level by approximately 0.3%). Wait 1 minute after each change in setting for the CO2 value to stabilize. If the value measured corresponds to the value given in the Table 33, max adjustment is complete. Otherwise continue the setting procedure.

4

Figure 76 - Max CO2 Adjustment

ATTENTION!! The Test Function will automatically deactivate after 30 minutes, or Test Function can be turned o manually by pressing the RESET button.

78