Install Instructions
99
107750-01 - 9/17
XI. Start-Up and Checkout (continued)
Table 11.4: Acceptable Combustion Readings for Natural Gas (0-2,000 ft.)
NOTICE
This boiler has a limited warranty, a copy of which is included with this boiler. It is the responsibility of
the installing contractor to see that all controls are correctly installed and are operating properly when the
installation is complete.
WARNING
Asphyxiation Hazard. Improper gas valve adjustments can result in unreliable operation, substantial
property damage, personal injury or loss of life due to carbon monoxide (CO) poisoning. Observe the
following precautions:
• Do not attempt to adjust gas valve without a combustion analyzer.
• Each boiler is tested at the factory and adjustments to the gas valve are normally not necessary
when operating on natural gas at sea level. Before making any adjustments, make sure that the analyzer
is calibrated and that combustion readings have stabilized.
• Regulator ("offset") screw used for low re adjustment is very sensitive. Adjust no more than 1/8
turn before checking combustion with analyzer. Maximum total regulator adjustment is ± 1 turn from
factory setting.
Table 11.5: Starting Number of Throttle Turns for Natural Gas
Model Size No. Counter-clockwise Turns (From Fully Closed)
320 5.5
399 7.0
Boiler Size
High Fire CO
2
Low Fire CO
2
*
Maximum CO Air-Free
Range Target Range Target
320
9.0% to 9.7% 9.5% 8.7% to 9.5%* 9.5% 200ppm
399
* Ensure low re CO
2
reading is less than or equal to high re CO
2
reading
Boiler Size
High Fire O
2
Low Fire O
2
**
Maximum CO Air-Free
Range Target Range Target
320
5.0% to 3.9% 4.2% 5.6% to 4.1% 4.2% 200ppm
399
** Ensure low re O
2
reading is greater than or equal to high re O
2
reading
NOTICE
In some cases, such as when the gas valve is replaced, the throttle may be far enough out of adjustment
that it is not possible to re the boiler while "dialing in" the CO
2
or (O
2
) using a combustion analyzer. In
such case, do the following:
1. Turn the throttle screw clockwise until stops turning.
2. For natural gas applications, turn the throttle screw counter-clockwise by the number of turns
shown in Table 11.5..
3. For LP gas applications set the preliminary throttle setting per conversion kit instructions.
4. Start the boiler using the lighting instructions on Page 100.
5. Once the boiler is ring, use a combustion analyzer to adjust the CO
2
(or O
2
) to its nal value as
described above.