NTI TRX150 High Efficiency Gas-Fired Condensing Boiler Instruction Manual

TRXTRX
NATURAL TO PROPANE
CONVERSION INSTRUCTIONS
Applicable Models:
TRX150, TRX199, and TRX199C

TRX150 High Efficiency Gas-Fired Condensing Boiler

WARNING
This conversion kit shall be installed 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 installation of this kit. THE INSTALLATION 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/O2 AND CO COMBUSTION ANALYZER.

Part 0. General Safety information

NTI boilers are factory set to operate with Natural Gas. BEFORE OPERATING WITH PROPANE the boiler must be converted to Propane using this kit. Use the procedures outlined in these instructions to fully complete the Natural Gas to LP conversion for models 150, 199, and 199C.
IF THE KIT CONTENTS DO NOT MATCH THOSE SPECIFIED FOR YOUR BOILER MODEL (SEE TABLE 1), DO NOT PROCEED WITH INSTALLING THE LP-CONVERSION KIT, AND DO NOT OPERATE THE BOILER – CONTACT NTI FOR ASSISTANCE.
Kit Contents:

Table 1 – LP Mixer and Gas diaphragm
**WARNING
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.
WARNING
** Breathing Hazard – Carbon Monoxide Gas

• Do not operate heater if flood damaged.
• Install vent system in accordance with local codes and manufacturers installation instructions.
• Do not obstruct heater air intake or exhaust. Support all vent piping per manufacturers installation instructions.
• Do not place chemical vapor emitting products near unit.
• According to NFPA 720, carbon monoxide detectors should be installed outside each sleeping area.
• Never operate the heater unless it is vented to the outdoors.
• Analyze the entire vent system to make sure that condensate will not become trapped in a section of vent pipe and therefore reduce the open cross sectional area of the vent.

Breathing carbon monoxide can cause brain damage or death. Always read and understand instruction manual.

Part 1 Propane Conversion Procedure

1. Install LP-Mixer with LP-Diaphragm
a. Check that the code of the air / gas mixer and the diameter of the gas diaphragm are those indicated for the model of boiler to be converted – see Table 1.
b. Turn the 120VAC power supply OFF to the boiler.
c. Turn the gas supply OFF.
d. Remove the front cover from the unit.
e. Remove the silencer. f. Unscrew the two nuts and remove the gas pipe.g. Remove the three bolts securing the NG-mixer to the blower and remove the NG-Mixer. Legend:

1. Mixer Tube (Replace with the LP-Mixer present in the Natural to LP Conversion Kit delivered with the boiler
2. LP Diaphragm (Install LP Diaphragm present in the Natural to LP Conversion Kit delivered with the boiler)
3. Gas Seal
4. O-Ring
5. Fan

NOTICE: Save the NG-mixer in-case the boiler needs to be converted back to Natural Gas at a later date.
h. Secure the LP-Mixer (with LP Diaphragm) to the blower in the same position as the removed NG-Mixer, reusing the bolts from the previous step.
NOTICE: Verify the O-ring seal between the mixer and blower is correctly positioned and in good condition before assembling.
i. Reassemble the gas pipe to the gas valve and mixer.
ATTENTION!! Use the new rubber gaskets provided with the kit.
j. Install the silencer.
2. Perform preliminary adjustment on gas valve throttle screw 4.
a. 150, 199, and 199C: Adjust throttle screw 4 – counter-clockwise 1.25 turns.
b. Turn the gas supply on and test for gas leaks in all piping.
c. Perform gas line pressure test and combustion calibration in accordance with Parts 2 and 3.

Part 2. Gas valve and burner setup

WARNING
Failure to perform the Gas Valve and Burner Setup correctly may result in incorrect operation, component failure, property damage, serious injury or death.

1. Operating Sequence
   Prior to commencing the Gas Valve and Burner Setup, perform the following operating sequence check:
   a. Turn the supply of gas to the boiler off.
   b. Set the thermostat to the highest setting.
   c. Ensure the combustion fan prepurges for a short time prior to activating the igniter.
   d. Ensure the combustion fan postpurges for at least 5 seconds prior to reactivating the igniter.
   e. Set the thermostat to the lowest setting and continue with the Gas Valve and Burner Setup procedure outlined below.

2. Gas Line pressure
   The boiler gas valve is equipped with a Line Pressure Test Port; see screw 1, Figure 4.
   Use the following procedure to measure the gas line pressure to the boiler to ensure it falls within the range given in Table 2:
   a. Turn the supply of gas to the boiler off.
   b. Loosen screw 1 (Torx 10 – Line Pressure Test Port). This port is directly connected to the gas line feeding the boiler. See screw 1, Figure 4.
   c. Connect a gas pressure gauge to the line pressure test port using applicable tubing. Ensure both ends of the tubing make a tight connection.
   d. Turn the gas supply to the boiler on and check for gas leaks.
   e. Observe the line pressure under static conditions and compare it to Table

3. The pressure will be greatest under static conditions.
   f. Observe the line pressure with the boiler running, while checking/ adjusting the CO2 at maximum and minimum gas flow rate (see Part. 3). Compare it to Table 2. The pressure will be lowest during the maximum flow of gas.
   g. Adjust the gas line pressure to ensure the parameters in Table 2 are attained under all conditions. If possible, adjust the line pressure to the “Nominal/Desired” value listed in Table 2 while the unit is operating at the maximum power.
   Continue observing gas line pressure until completing of necessary Checking/ Adjusting of the CO2 (see Part 3), in case adjustments need to be made.
   h. Complete pressure testing. Remove the tubing from the test port and then return the bleed screw of the Line Pressure Test Port to the closed position. Check for gas leaks.

| Line Pressure (inches w.c.)
---|---
Nominal| Min.| Max.
Natural| 7| 3.5| 10.5
Propane| 11| 8| 13

DANGER
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.
NOTICE
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.

Part 3. Checking/Adjusting the CO2

WARNING
Adjustments to the Gas valve may only be made by a qualified gas technician, while using a calibrated combustion analyzer capable of measuring CO2 and CO. Adjustments may only be performed if the gas line pressure is maintained above minimum levels throughout the duration of the test. See Table 3. Failure to follow these instructions may result in serious injury or death.
WARNING
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.

1. Preparing the measuring equipment
   Remove the flue test port plug as illustrated, and insert a calibrated combustion analyzer.
   NOTICE
   Make sure the analyzer is set to the appropriate fuel.

WARNING
It is required to use a calibrated combustion analyzer to verify final adjustment according to the combustion chart (Table 3). Failure to do so could result in serious personal injury or death.
WARNING
It is very important that the combustion system be set within the recommended CO2/ CO measurements listed in Table 3. Visually looking at the burner does not determine combustion quality. Failure to measure combustion with a calibrated combustion analyzer and set the throttle within the recommended CO2/CO measurements could result in property damage, severe personal injury, or death.
2. Checking/Adjusting the CO2 at Maximum Gas Flow Rate (High Fan Speed)
Set the thermostat at the highest possible setting or draw off the domestic hot water at the maximum water flow rate to create a demand for heat.
NOTE: For only Heating Boiler Applications, open all thermostatic valves present in the CH circuit.
Select the TEST Function by pressing and holding the RESET button for 10 seconds.
WARNING! WHEN THE TEST FUNCTION IS ACTIVATED THE TEMPERATURE OF THE WATER COMING OUT OF THE BOILER MAY BE MORE THAN 150°F.
and the icon appear on the display when Test Function is active.
The boiler will operate at maximum heating power.
Press the button to operate the boiler at maximum power.
The icon will display.![NTI TRX150 High Efficiency Gas-Fired Condensing Boiler

• fig 8](https://manuals.plus/wp-content/uploads/2023/08/NTI-TRX150-High- Efficiency-Gas-Fired-Condensing-Boiler-fig-8.jpg)Wait 1 minute for the boiler to stabilize before carrying out the combustion analyses.
  Read the CO2 value (%) and compare it with the values given in the table below:

Table 3 – CO2 max-min
ATTENTION: The CO2 at minimum gas flow rate (Low Fan Speed) must be set lower than the CO2 reading at maximum gas flow rate (High Fan Speed) by 0.5 to 1.0%. For Example: If CO2 at High = 9.2%, then CO2 at Low must = 8.7% – 8.2%
ATTENTION!! VALUES MUST BE OBTAINED WITH THE FRONT COVER INSTALLED.
If the CO2 reading differs from the values given in the table, then adjust the gas valve following the instructions below. Otherwise move directly to next operation.
ADJUSTING THE GAS VALVE AT MAXIMUM GAS FLOW
Adjust the gas valve by turning setting screw 4 clockwise to increase the CO2 level; counterclockwise to reduce the CO2 level (1 turn adjusts the CO2 level by approximately 0.3%). Wait 1 minute after each change in setting for the CO2 value to stabilize.
If the value measured corresponds to the value given in Table 3, max adjustment is complete.
Otherwise continue the setting procedure. ATTENTION!!
Test Function will automatically deactivate after 30 minutes.
Test Function can be turned off manually by pressing the RESET button.
3. Checking/Adjusting the CO2 at MINIMUM Gas Flow (Low Fan Speed)
With Test Function active, press the button to operate the boiler at minimum DHW power. The and icons will display.Wait 1 minute for the boiler to stabilize before carrying out the combustion analyses.
If the CO2 (%) reading at min gas flow is greater than the CO2 (%) reading at max flow, or if it is less than the reading at max flow by more than 1.0%, adjust the gas valve following the instructions below. Otherwise move directly to next operation.
ADJUSTING THE GAS VALVE AT MINIMUM GAS FLOW
Remove cap and adjust screw 2 by turning counter – clockwise to reduce the CO2 level; clockwise to increase the CO2 level.
Wait 1 minute after each adjustment for the CO2 value to stabilize.
WARNING! MINIMUM GAS FLOW ADJUSTMENT IS VERY SENSITIVE.
If the value measured corresponds to the value given in Table 3 adjustment is complete. Otherwise continue the setting procedure. ATTENTION!! IF THE VALUE OF THE CO2 AT MINIMUM POWER HAS BEEN CHANGED, IT IS NECESSARY TO REPEAT THE ADJUSTING AT MAXIMUM GAS FLOW.

1.Canada: Altitudes between 2000-4500 ft de-rate by 10%. Consult local authorities for de-rating for altitudes above 4500ft.
2.USA: De-rate capacity by 4% for every 1000 ft above sea level, if altitude is above 2000 ft.

Table 4 Minimum and Maximum Gas Flow
4. Ending Adjustment

1. Exit Test Mode by pressing RESET.
2. Turn down the thermostat and / or stop the DHW draw-off. For Only Heating Boiler applications reset all thermostatic valves.
3. Reinstall the combustion test port. See Figure 6.
4. Check for and repair any leaks of gas.
5. Reinstall the front cover.

WARNING
Carbon Monoxide – Never leave the unit operating while producing Carbon Monoxide (CO) concentrations in excess of the values indicated in Table 3. Failure to follow this warning may result in serious injury or death.
WARNING
Breathing Hazard – Carbon Monoxide Gas

• Do not operate heater if flood damaged.
• Install vent system in accordance with local codes and manufacturers installation instructions.
• Do not obstruct heater air intake or exhaust. Support all vent piping per manufacturers installation instructions.
• Do not place chemical vapor emitting products near unit.
• According to NFPA 720, carbon monoxide detectors should be installed outside each sleeping area.
• Never operate the heater unless it is vented to the outdoors.
• Analyze the entire vent system to make sure that condensate will not become trapped in a section of vent pipe and therefore reduce the open cross sectional area of the vent.

Breathing carbon monoxide can cause brain damage or death. Always read and understand instruction manual.
5. Update rating plate
As the certified installer of the Natural Gas to LP Conversion Kit, you must indicate on the boiler that it has been converted for use with Propane (LP) Gas:
a. 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. Press hard enough to permanently mark the decal. See Figure 9.
FACTORY SET FOR NATURAL GAS
Field converted to Propane Gas
Date: October 22,2018
ADJUSTER A L’USINE POUR GAZ NATURAL
Convertie au propane sur place
Date: …………………………….

Figure 8 – Update the Rating Plate Decal
b. 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, in a location where it can be easily seen. See Figure 10.
THIS CONTROL WAS CONVERTED FOR USE WITH PROPANE GAS
This appliance has been converted for use with Propane Gas, in accordance with the
instructions provided with the Natural to Propane Conversion Kit by John Smith , which accepts responsibility that the conversion was performed properly.
Reference rating plate for Propane Input and Gas Pressure
420060882600
Figure 9 – Conversion Decal

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NTI Boilers Inc.
30 Stonegate Drive Saint John,
NB E2H 0A4 Canada
Technical Assistance: 1-800-688-2575
Website: www.ntiboilers.com
Fax: 1-506-432-1135
420020241400

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