Intellihot iN199, Installation & Operation Manual

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31 iN199 Adjusting CO2 Level
November 2021 - Revision 00
10. Adjusting CO
2
Level
10.1 General Information
This procedure is required:
1. Only during installation in a high-altitude location over
8,000 feet, or
2. When converting the unit from natural gas to propane.
This procedure should be completed only by a qualified
technician.
DANGER
A concentration of carbon monoxide (CO) as small as
0.04% (400 parts per million) in the air can be fatal. When
making High Fire and/or Low Fire adjustments, CO levels
must be monitored using a flue gas analyzer and must not
exceed 400 ppm of CO at any time during the operation.
Adjusting the “Low Fire screw” or the “High Fire screw”
even in small increments can result in a significant
increase in CO concentration. To avoid serious injury or
death, DO NOT adjust the gas valve without monitoring
the exhaust gases with a functional and calibrated flue
gas analyzer.
CO
2
and CO Standards
Description CO
2
Range (%) Max. CO Level (ppm)
Natural Gas
High Fire 9.1% to 9.3% < 200 ppm
Low Fire 9.1% to 9.3% < 60 ppm
Propane
High Fire 10.1% to 10.5% < 200 ppm
Low Fire 10.1% to 10.5% < 60 ppm
NOTICE
1. The values listed in the table are for nominal conditions.
Variables such as gas pressure, heating value of the
gas, humidity, and temperature of combustion air can
impact CO and CO2 values. Changes in these variables
can result in different CO and CO2 values on the same
water heater.
2. A qualified service technician must use a calibrated
flue gas analyzer to adjust the gas valve to achieve the
desired CO
2
and CO values.
3. Before any adjustments are made, the service technician
must confirm the static gas pressure meets these minimum
requirements: Natural Gas - 8" WC; Propane - 11" WC.
4. If units are cascaded and common-vented, these
combustions must be done on only one unit at a time.
Turn off the valve to the hot water outlet of the other
units and power off before doing combustion.
10.2 Adjustment Procedure
1. Open or remove the front doors.
2. Locate the gas valve as shown in illustration.
3. Remove the plug from the test port on the exhaust
manifold.
4. Insert a calibrated flue gas analyzer into the test port.
5. Follow the display screens.