4
Adjustment
Throttle / Input Screw Adjustments -
The boiler is equipped with a Throttle/Input Adjustment Screw, located under
a plastic cap on the top of the Gas Valve; see Figure 1-1. It is used to adjust the flow of gas leaving the gas valve
entering the Venturi and then the combustion air stream. Turn the Throttle screw in (clockwise) to reduce the flow
of gas, make combustion leaner, and reduce the concentration of CO
2
in the flue gases. Turn the Throttle screw out
(counterclockwise) to increase the concentration of CO
2
and flow of gas in the combustion air stream.
Typical
adjustment required is 0-1/8 of a turn in or out from starting point (see Section 1.0). See Figure 1-1 for Throttle
screw location and Table 2-1 for appropriate CO
2
levels.
Combustion Calibration
- To calibrate burner operation, perform the following procedure using a calibrated
combustion analyzer capable of measuring CO
2
and CO from Natural and Propane Gas burning boilers:
1.
Operate the unit at the maximum modulation rate, see Table 2-2.
2.
Ensure the gas line pressure is maintained within tolerance, see Table 2-1.
3.
While at the maximum modulation rate, measure the CO
2
and CO; adjust as necessary, using the Throttle
Screw, to be within the limits listed in Table 2-1.
4.
Operate the unit at the minimum modulation rate (see Table 2-2). Ensure the combustion remains smooth
and CO
2
and CO values are lower than the values obtained during maximum modulation, as per notes in
Table 2-1. If not, do not adjust further, contact NTI for assistance.
Failure to perform the flue gas analysis and adjustment as detailed in this section may result in
erratic and unreliable burner operation, leading to reduced efficiency, increased fuel
consumption, reduced component life, heat exchanger combustion deposits, and general
unsafe operation. Failure to follow these instructions may result in serious injury or death.
3.0 Labeling
As the certified installer of the LP Conversion Kit, you must indicate on the boiler that it has been converted for use
with Propane (LP) Gas:
1.
Update Rating Plate Decal
– Locate the rating plate decal on the side of the appliance, using a regular ink pen,
check the box next to “Field converted to Propane Gas” and fill in the date; depress hard enough to permanently
etch the decal (see Figure 3-1).
2.
Conversion Decal
- Fill out the required information on the Conversion Decal (included in this kit) and affix it to
the boiler cabinet adjacent to the rating plate decal, and in a location where it can be easily seen (see Figure 3-2).
Figure 3-1 Update the Rating Plate Decal
Figure 3-2 Conversion Decal
X
March 29, 2016
Throttle/Input Adjustment Screw
Increase gas
Turn Counter Clockwise
Decrease gas
Turn Clockwise
Throttle/Input Adjustment Screw
Increase gas
Turn Counter Clockwise
Decrease gas
Turn Clockwise
John Smith
