NTI FTG 600 User manual

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Firetube Giant FTG 600-1400
NATURAL GAS TO LP CONVERSION INSTRUCTIONS:
Version Date: 2019-11-28
Kit Number: 85418-1
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 85445)
Natural Gas to LP Conversion Decal (p/n 85418)
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 # 85445
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 600, FTG 800, FTG 1200 & FTG 1400 are converted from Natural to LP Gas by
adjusting the Throttle Screw located on the gas valve; unlike most LP conversions an LP
orifice is NOT used.
1. Locate the Throttle 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) ½ of a turn (¾ of a turn for FTG 1400).
4. Proceed to Section 2.0, Gas Valve and Burner Setup, for instructions on how to test the Gas Line Pressure and
perform the Combustion Calibration.
Figure 1-1 Gas Valve Assembly
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 Valve
Throttle Screw –used to calibrate
combustion at max. modulation rate (use
3 mm hex wrench). Pre-set by turning
screw all the way in (clockwise) until it
stops, then turn out (counterclockwise) ½
a turn (3/4 of a turn for FTG 1400)
Line Pressure Test Port
(located on gas valve inlet
flange)
Venturi
Combustion Blower
Air Filter
Cap (remove to access the
Throttle Screw)
Low Gas Pres. Switch
(auto-reset)
High Gas Pres. Switch
(manual reset)
Offset Screw –used to set
combustion at min. modulation rate;
must remove cap first
(use T40 Torx wrench)

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Combustion Calibration Procedure
To calibrate burner combustion, perform the following procedure using a calibrated combustion analyzer capable of
measuring CO2and CO from a Natural Gas or Propane burning appliance:
1. Set analyzer to the appropriate fuel (Propane).
2. Gas Line Pressure Test –monitor gas line pressure throughout all combustion tests and verify it is maintained
within tolerance. See Gas Line Pressure Test below.
3. Set Throttle Screw –operate burner to the maximum modulation rate (see Table 2-2); set combustion according
to Table 2-1 using the Throttle Screw; allow time for the analyzer readings to stabilize between adjustments –
record CO2value. See Throttle Screw Adjustment below.
4. Set Offset Screw –operate burner to the minimum modulation rate (see Table 2-2); using the Offset Screw, set
the CO2to 0.5-1.0% lower than the value obtained during the maximum modulation rate test (e.g. if CO2at Max
= 10%, then CO2at Min must = 9.0-9.5%). See Offset Screw Adjustment below.
Combustion Calibration is mandatory upon installation and during each annual service.
Failure to perform the Combustion Calibration in accordance with these instructions may
result in incorrect combustion leading to burner damage or excessive Carbon Monoxide
concentrations causing property damage, personal injury or death.
Carbon Monoxide - Never leave the unit operating while producing Carbon Monoxide (CO)
concentrations in excess of 175 ppm. Failure to follow this warning may result in serious
injury or death.
Throttle Screw Adjustment
The gas valve Throttle Screw (see Figure 1-1) is used to calibrate the CO2concentration with the burner operating at
or near the maximum modulation rate (see Table 2-2). Turning the Throttle Screw in (clockwise) decreases the CO2
concentration. Turning the Throttle Screw out (counterclockwise) increases the CO2 concentration. Typical
adjustment required is 0 - 1/8th of a turn in or out from the position established in Section 1.0 above.
NOTE: Calibration of the Throttle Screw should only be performed with the burner operating at or near the
maximum modulation rate (see Table 2-2).
Adjustments to the Throttle Screw may only be made by a qualified gas technician 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.
Offset Screw Adjustment
The gas valve Offset Screw (see Figure 1-1) is used to calibrate the CO2offset at minimum modulation vs. maximum
modulation. Turning the Offset Screw in (clockwise) increases the CO2 concentration at minimum modulation rate.
Turning the Offset Screw out (counterclockwise) decreases the CO2 concentration at minimum modulation rate.
Typical adjustment required is 0 - 1/8th of a turn in or out from the factory setting.
NOTE: Calibration of the Offset Screw must only be performed with the burner operating at the minimum
modulation rate (see Table 2-2).
Adjustments to the Offset Screw may only be made by a qualified gas technician using a
calibrated combustion analyzer capable of measuring CO2and CO, and only with the burner
at the minimum modulation rate (see Table 2-2). Attempting to set the Offset Screw while the
burner is operating at a modulation rate other than the minimum will result in incorrect
combustion and may lead to burner damage or excessive CO.

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Gas Line Pressure Test
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. Using a 3/16 in. hex wrench, remove the plug from the flange located at the inlet of the gas valve, identified as
Line Pressure Test Port in Figure 1-1. In place of the plug, install a 1/8 NPT x hose barb adapter, suitable for
connecting the tubing of the gas pressure manometer being used to measure gas line pressure.
3. Slide the gas pressure manometer tubing over the hose barb adapter installed in step 2; connect the other end of
the tubing to 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. Complete pressure testing, turn the gas supply off, and then reinstall the Line Pressure Test Port plug, applying
appropriate thread sealant to the threads prior to installing. 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 install the Line Pressure Test Port plug 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 w.c.)
CO2(%) 1
CO (ppm)
Max. 1
Nominal/Desired
Min.
Max.
Min.
Max.
Natural
7
4
10.5
8.3
9.3
175
Propane
11
8
13
9.6
10.6
175
Notes:
1Combustion values listed are for burner operation at maximum modulation rate; when tested at minimum modulation
rate the CO2must be 0.5-1.0% lower than CO2at maximum modulation rate.
Table 2-2 Minimum and Maximum Modulation and Input Rates
Model
Min. Modulation Rate (RPM)
Max. Modulation Rate (RPM)
Input Rate (MBH)
Min
Max 1
FTG 600
1150
5600
80
600
FTG 800
1150
7450
80
800
FTG 1200
1050
8100
120
1200
FTG 1400
1050
7800
140
1400
Notes:
1Canada: Altitudes between 2000-4500 ft, de-rate by 10%. Consult local authorities for de-rating for altitudes above 4500ft.
2Use Diagnostic Test, accessed from the Diagnostic menu of the display, to force max. and min. modulation rates; see
Appendix A –Controller and Touchscreen Display Instructions, Section 5 DIAGNOSTICS PAGE.

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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