NTI Trinity Lx 500 User manual

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Trinity Lx500 & Lx500WH
NATURAL TO LP CONVERSION INSTRUCTIONS:
Version Date: 2016-07-04
Kit Number: 84386-1
NTI Trinity boilers and water heaters are factory equipped to operate with Natural Gas. BEFORE OPERATING
WITH PROPANE the appliance gas valve must be adjusted according to these instructions. Use the procedures
outlined in these instructions to fully complete the Natural Gas to LP conversion.
Kit Contents:
Natural to LP Conversion Instructions
Natural to LP Conversion Decal (p/n 84386)
These instructions CANNOT be used to convert NTI appliance models not referenced in these
instructions. Contact NTI for the Natural Gas to LP conversion kit and instructions for other
models.
Failure to apply these instructions properly may result in dangerous Carbon Monoxide levels,
fire or explosion leading to property damage, personal injury or death.
ATTENTION: LIQUEFIED PETROLEUM (LP) PROPANE
Liquefied Petroleum (LP) propane gas is heavier than air; therefore, it is imperative that your boiler is not
installed in a pit or similar location that will permit heavier than air gas to collect. Local Codes may require
appliances fueled with LP gas be provided with an approved means of removing unburned gases from the
room. Check your local codes for this requirement.
This conversion shall be performed by a qualified service agency in accordance with
the manufacturer’s instructions and all applicable codes and requirements of the
authority having jurisdiction. If the information in these instructions is not followed
exactly, a fire, an explosion or production of carbon monoxide may result causing
property damage, personal injury or loss of life. The qualified service agency is
responsible for the proper application of these instructions. The conversion is not
proper and complete until the operation of the converted appliance is checked as
specified in the manufacturer’s instructions supplied with the kit, which necessitates
the use of a calibrated CO2/O2and CO combustion analyzer.

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1.0 Adjusting the Gas Valve
The Lx500 & Lx500WH is converted from Natural to LP Gas by adjusting a Throttle/Input
Screw located on the gas valve; unlike most LP conversions an LP orifice is NOT used.
1. Locate the Throttle/Input Adjustment Screw on the gas valve, see Figure 1-2.
2. Turn the Throttle Screw all the way in (clockwise until it stops).
3. Turn the Throttle Screw counterclockwise (out) 4-1/2 turns.
4. Proceed to Section 2.0, Gas Valve and Burner Setup.
2.0 Gas Valve and Burner Setup
Failure to perform the Gas Valve and Burner Setup correctly may result in incorrect
operation, component failure, property damage, serious injury or death.
Operating Sequence
Prior to commencing the Gas Valve and Burner Setup, perform the following operating sequence check:
1. Turn the supply of gas to the boiler off.
2. Set the thermostat to the highest setting.
3. Ensure the combustion fan pre-purges for a short time prior to activating the igniter.
4. Ensure the combustion fan post-purges for at least 5 seconds prior to reactivating the igniter.
5. Set the thermostat to the lowest setting and continue with the Gas Valve and Burner Setup procedure outlined
below.
Gas Line Pressure
The boiler gas valve is equipped with a line pressure test port; see Figure 1-1. Use the following procedure to
measure the gas line pressure to the boiler to ensure it falls within the range given in Table 2-1:
1. Turn the supply of gas to the boiler off.
2. Open the bleed screw of the line pressure test port approximately 1-1/2 turns. This port is directly connected to
the gas line feeding the boiler. See Figure 1-1.
3. Force 1/4ID tubing over the housing of the line pressure test port; install the other end of the tubing to an
appropriate line pressure test gauge or manometer. Ensure both ends of the tubing make a tight connection.
4. Turn the gas supply to the boiler on and check for gas leaks.
5. Observe the line pressure under static conditions and compare it to Table 2-1. The pressure will be greatest
under static conditions.
Figure 1-2 Adjustment
Throttle/Input
Adjustment Screw
Input Screw
Decrease gas input
Turn Clockwise
Increase gas input
Turn Counterclockwise
Figure 1-1 Test Pressure
Manifold Pressure Test Port
(pressure need-not be
tested or adjusted)
Line Pressure Test Port
(in. w.c.)
Setting Min. Max.
Natural Gas 7” 5.5” 10.5”
Propane 11” 9” 13”

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6. With all other gas appliances in the application running, operate the burner to the maximum firing rate (See I/O
manual) and compare the observed line pressure with Table 2-1. The pressure will be lowest during the
maximum flow of gas.
7. Adjust the gas line pressure to ensure the parameters in Table 2-1 are attained under all conditions. If possible
adjust the line pressure to the "Nominal/Desired" value listed in Table 2-1 while the unit is operating at the
maximum modulation rate.
8. Continue observing the gas line pressure until the completion of a combustion analyses in case adjustments need
to be made.
9. Complete pressure testing, remove the ¼” tubing from the test port and then return the bleed screw of the Line
Pressure Test Port to the closed position.
The line pressure is a function of the gas supply and is affected solely by field provided
parameters such as line size and regulator settings. Under no circumstances can the boiler gas
valve influence or be used to adjust the gas line pressure.
Failure to close the bleed screw of the Line Pressure Test Port will cause a severe leakage of
gas, resulting in a fire or explosion causing property damage, serious injury or death.
Table 2-1 Line Pressure and Combustion Parameters
Gas
Line Pressure (inches wc)
CO2(%)*
CO (ppm)
Max.*
Nominal/Desired
Min.
Max.
Min.
Max.
Natural
7
5.5
10.5
8.8
9.8
175
Propane
11
8
13
9.8
10.8
175
*Note: Observe the combustion products with the burner operating at the maximum modulation rate.
Table 2-2 Minimum and Maximum Input Ratings and Respective Modulation Rates
Model
Min. Modulation Rate
(RPM)
Max. Modulation Rate
(RPM)
Input (MBH)
Min
Max*
Lx500 & Lx500WH
1400
6400
100
500
* Canada: Altitudes between 2000-4500 ft, de-rate by 10%. Consult local authorities for de-rating for altitudes above 4500ft.
Carbon Monoxide –DO NOT leave the unit operating if producing Carbon Monoxide (CO)
concentrations in excess of 175ppm. Failure to comply may result in serious injury or death.
Manifold Pressure - DO NOT adjust or measure the Manifold Pressure of the boiler. Correct
manifold pressure is factory set. Field adjustment could result in improper burner operation
resulting in fire, explosion, property damage or death.
Adjustment
Throttle / Input Screw Adjustments - The boiler is equipped with a Throttle/Input Adjustment Screw, located on the
Gas Valve. It is used to adjust the flow of gas leaving the gas valve entering the Venturi and then the combustion
air stream. Turn the adjustment screw in (clockwise) to reduce gas flow, make combustion leaner, and reduce the
CO2concentration in the flue gases. To increase the CO2level and gas flow in the combustion air stream, adjust
the Throttle screw out (counterclockwise). Typical adjustment for LP Gas is 0-1 turns in or out after having
performed the initial adjustment as per Section 1.0. See Figure 1-2 for throttle screw location.
Adjustments to the Throttle/Input-Screw may only be made by a qualified gas technician
while using a calibrated combustion analyzer capable of measuring CO2and CO.
Adjustments may only be performed if the gas line pressure is maintained above minimum
levels throughout the duration of the test, see Table 2-1. Failure to follow these instructions
may result in serious injury or death.
Throttle/Input Adjustment Screw
Increase gas
Turn Counter Clockwise
Decrease gas
Turn Clockwise

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Combustion Calibration - To calibrate burner operation, perform the following procedure using a calibrated
combustion analyzer capable of measuring CO2and 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 CO2and 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 (Table 2-2). Ensure the combustion remains smooth and CO2
and CO values are lower than the values obtained during maximum modulation (Table 2-1). If not, do not
adjust further, contact NTI for assistance.
Failure to perform the flue gas analysis and adjustment 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


This appliance was modified with kit #84386-1, by
,
which accepts responsibility that this conversion
was completed properly.
THIS CONTROL WAS CONVERTED FOR USE
WITH _______GAS.
Reference rating plate for propane Input and Gas Pressure.
Attach this decal
below the existing
rating plate decal.
X
January 12, 2015