NTI FTG 2000 User manual

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Firetube Giant FTG 2000-2400
NATURAL GAS TO LP CONVERSION INSTRUCTIONS:
Version Date: 2017-08-18
Kit Number: 85758-1
NTI boilers are factory equipped to operate with Natural Gas. BEFORE OPERATING WITH PROPANE the
boiler’s 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 Gas to LP Conversion Instructions (p/n 85759)
Natural Gas to LP Conversion Decal (p/n 85758)
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.
NTI # 85759
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 FTG 2000, FTG 2200 & FTG 2400 are converted from Natural to LP Gas by adjusting
the Throttle/Input Screw located on the gas valve; unlike most LP conversions an LP orifice
is NOT used.
1. Locate the Throttle Adjustment Screw on the gas valve, see Figure 1-1.
2. Turn the Throttle Screw all the way in (clockwise until it stops).
3. Turn the Throttle Screw counterclockwise (out) 2-1/4turns.
4. Proceed to Section 2.0, Gas Valve and Burner Setup, for instructions on how to test the Gas Line Pressure,
perform the Combustion Calibration, and test the Gas Valve Offset Pressure.
Figure 1-1 Gas Valve Assembly
Pressure Tappings for Measuring Offset
(Refer to Offset Adjustment Procedure –
Figure 2-1)
Gas Valve
Offset Adjustment Screw
(Refer to Offset Adjustment
Procedure –Figure 2-1)
Throttle Adjustment Screw –
turn screw all the way in (clockwise)
until it stops, then turn out
(counterclockwise) 2-1/4turns; then
proceed with Combustion Calibration.
Line Pressure Test Port
(located on gas valve inlet
flange)
Venturi
Combustion Blower
Air Filter
Low Gas Pres. Switch
(auto-reset)
High Gas Pres. Switch
(manual reset)

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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 at least 30 seconds prior to activating the igniter.
4. Ensure the combustion fan post-purges for at least 60 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 if falls within the range given in Table 2-1:
1. Turn the supply of gas to the boiler off.
2. A bleed screw is located on the inlet flange of the gas valve; open it approximately 1-1/2 turns. See Line
Pressure Test Port in Figure 1-1.
3. Slide the gas pressure manometer tubing over the bleed screw fitting located on the inlet flange of the gas valve;
connect the other end of the tubing to the gas pressure manometer. Ensure both ends of the tubing make a tight
connection.
4. Open the supply of gas to the boiler 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.
6. With all other gas appliances in the application running, operate the burner to the maximum firing rate (see Table
2-2) 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 (see NOTICE
below). 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, see Table 2-2.
8. Continue observing the gas line pressure until the completion of the combustion analyses, in case adjustments
need to be made.
9. Upon completion of the line pressure testing, turn the gas supply off and close the bleed screw. Turn gas on and
check for leaks.
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 properly close the Line Pressure Test Port bleed screw will cause 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 w.c.)
Offset Pressure
(inches w.c. / [Pa])4
CO2(%)1,2,3
Max. CO
(ppm)
Nominal/
Desired
Min.
Max.
Min.
Max.
Natural
7
4
10.5
-0.01 to 0 / [-3 to -1]
8.7
9.5
175
Propane
11
8
13
-0.04 to -0.03 / [-10 to -8]
10
10.8
175
Notes:
1Combustion calibration must only be performed with the burner operating at maximum modulation rate.
2Combustion values listed are for burner operation at maximum modulation rate; CO2 and CO values will be lower at
minimum modulation rate.
3When tested at minimum modulation rate, the CO2must be 0.5-1.0% lower than CO2at maximum modulation rate.
4The Offset Pressure for models FTG 2000-2400 converted to Propane, must be checked, and if necessary adjusted, in
accordance with the procedure detailed in Figure 2-2.

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Table 2-2 Minimum and Maximum Modulation Rates
Model
Min. Modulation Rate (RPM)
Max. Modulation Rate (RPM)
Input Rate (MBH)
Min
Max *
FTG 2000
1050
7100
235
2000
FTG 2200
1050
7200
235
2200
FTG 2400
1050
8000
235
2350
* Canada: Altitudes between 2000-4500 ft, de-rate by 10%. Consult local authorities for de-rating for altitudes above 4500ft.
Carbon Monoxide - Never leave the unit operating while producing Carbon Monoxide (CO)
concentrations in excess of 175ppm. Failure to follow this warning may result in serious
injury or death.
Adjustments to the Throttle Adjustment 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.
Flue Gas Analysis and Adjustment
Throttle Adjustment Screw –The boiler is equipped with a Throttle Adjustment Screw, located at the Gas Valve;
see Figures 1-1 & 2-1; 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 CO2in the flue gases. Turn the Throttle screw out (counterclockwise) to increase
the concentration of CO2and flow of gas in the combustion air stream.
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. Perform the Gas Valve Offset Check/Adjustment procedure detailed in Figure 2-2.
5. Operate the unit at the minimum modulation rate (see Table 2-2). Ensure the combustion remains smooth
and CO2and 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.
Each FTG boiler is factory set to operate with Natural Gas, for boilers field converted to operate with Propane Gas, a
FLUE GAS ANALYSIS AND ADJUSTMENT IS MANDATORY.
Failure to perform the flue gas analysis and adjustment 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.
Throttle Adjustment Screw
Increase gas
Turn Counter Clockwise
Decrease gas
Turn Clockwise

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Figure 2-1 Gas Valve Offset Check/Adjustment
The Gas Valve Offset Pressure is factory set for Natural Gas; only applications operating
with Propane need to have the Gas Valve Offset Pressure field adjusted.
Improperly adjusted Gas Valve Offset Pressure will result in unpredictable burner operating
characteristics, which may lead to burner malfunction causing property damage, serious injury
or death.
Offset Adjustment Screw –used
to set offset and combustion at min.
modulation rate; see Figure 1-1
Differential Pressure
Manometer –min. graduation
of 0.01 in. w.c (1 Pa)
Offset Adjustment Procedure:
1) Differential Pressure Manometer –
obtain a meter capable of measuring
differential pressure (“+” and “-“ ports)
with a minimum graduation of 0.01
inches w.c. (or 1 Pa).
2) Installation –with the burner off,
remove the caps from the pressure
tappings. Connect the Feedback
Pressure Tapping to the Positive (+) port
of the manometer; connect the Manifold
Pressure Tapping to the Negative (-)
port of the manometer. Verify that the
manometer is reading zero –zero the
meter if necessary.
3) Calibrate Combustion –operate burner
to maximum modulation rate (see Table
2-2), ensuring gas line pressure is
maintained above 4 inches w.c.; set
combustion according to Table 2-1 using
the Throttle Screw –record CO2value.
4) Set Offset –operate burner to minimum
modulation rate (see Table 2-2); set
offset pressure according to Table 2-1
using the Offset Adjustment Screw.
NOTICE: Since the Manifold Pressure
Tapping is connected to the Negative (-)
port of the manometer, a negative Offset
Pressure will read positive; e.g., to
achieve an offset pressure of -0.03,
manometer will read +0.03.
5) Verify Combustion –with the burner
remaining in operation at the minimum
modulation rate, measure combustion
and compare to readings obtained
during maximum modulation –CO2must
be 0.5 to 1.0% lower at minimum
modulation. If readings are out of
tolerance –CONTACT NTI FOR
ASSISTANCE.
6) Complete Test –shutdown the burner,
remove the manometer tubing and
reinstall the factory caps on Offset
Pressure Tappings.
Positive (+)
Negative (-)
Feedback
Pressure
Manifold
Pressure
Throttle Adjustment Screw –
used to calibrate combustion at max.
modulation rate; see Figure 1-1

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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
John Smith