NTI FTVN199C - User Manual

Other manuals for NTI FTVN199C

Installation Start-Up Maintenance124 pages

Conversion Instructions12 pages

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Summary

Part 0. General Safety Information

Safety Warnings and Applicability

Key safety warnings, instruction applicability, and LP gas hazards.

Part 1. Propane Conversion Procedure

Install LP-Mixer with LP-Diaphragm

Step-by-step guide for installing the LP mixer and diaphragm.

Perform Preliminary Gas Valve Adjustment

Adjusting the gas valve throttle screw for initial setup.

Part 2. Gas Valve and Burner Setup

Operating Sequence

Pre-setup checks and operating sequence for gas valve and burner.

Gas Line Pressure Measurement

Procedure for measuring and adjusting gas line pressure.

Part 3. Checking;Adjusting the CO2

Prepare Measuring Equipment

Instructions for preparing the measuring equipment and test port.

Adjust CO2 at Maximum Gas Flow

Detailed procedure for adjusting CO2 levels at high fan speed.

Adjust CO2 at Minimum Gas Flow

Detailed procedure for adjusting CO2 levels at low fan speed.

Finalize Adjustment and Update Rating Plate

Exiting test mode, final checks, and updating the appliance rating plate.

Summary

Part 0. General Safety Information

Safety Warnings and Applicability

Key safety warnings, instruction applicability, and LP gas hazards.

Part 1. Propane Conversion Procedure

Install LP-Mixer with LP-Diaphragm

Step-by-step guide for installing the LP mixer and diaphragm.

Perform Preliminary Gas Valve Adjustment

Adjusting the gas valve throttle screw for initial setup.

Part 2. Gas Valve and Burner Setup

Operating Sequence

Pre-setup checks and operating sequence for gas valve and burner.

Gas Line Pressure Measurement

Procedure for measuring and adjusting gas line pressure.

Part 3. Checking;Adjusting the CO2

Prepare Measuring Equipment

Instructions for preparing the measuring equipment and test port.

Adjust CO2 at Maximum Gas Flow

Detailed procedure for adjusting CO2 levels at high fan speed.

Adjust CO2 at Minimum Gas Flow

Detailed procedure for adjusting CO2 levels at low fan speed.

Finalize Adjustment and Update Rating Plate

Exiting test mode, final checks, and updating the appliance rating plate.

This document provides instructions for converting NTI boilers from Natural Gas to Propane (LP) gas. The conversion is critical for safe and efficient operation when switching fuel types.

Function Description

The NTI boiler conversion kit facilitates the change of an NTI boiler's fuel source from Natural Gas to Liquefied Petroleum (LP) propane gas. NTI boilers are factory-set to operate with Natural Gas, and this kit is essential for adapting them to Propane. The conversion involves replacing specific components and adjusting the boiler's settings to ensure proper combustion and safety with the new fuel. This process is not merely a simple swap but requires careful calibration and verification to prevent hazardous conditions such as fire, explosion, or carbon monoxide production.

The core of the conversion involves installing an LP-Mixer with a specific LP-Diaphragm, which is crucial for regulating the gas-air mixture appropriate for propane combustion. Propane gas has different combustion characteristics and is heavier than air, necessitating distinct components and settings compared to natural gas. The kit ensures that the boiler's gas valve and burner setup are correctly configured for LP gas, including adjustments to gas line pressure and combustion parameters.

Usage Features

The conversion process outlined in the manual is designed for qualified service agencies, emphasizing the technical nature of the task. It begins with a verification of the kit contents against the specific boiler model to ensure compatibility. If the kit contents do not match, the installation should not proceed, and NTI should be contacted for assistance.

Key steps in the conversion include:

Preparation: Turning off the 120VAC power supply to the boiler and the gas supply, then removing the front cover and silencer.
Component Replacement: Unscrewing the gas pipe, removing the existing Natural Gas (NG) mixer, and securing the new LP-Mixer (with the LP Diaphragm) to the blower. It's crucial to reuse the bolts from the previous step and verify the O-ring seal between the mixer and blower is correctly positioned and in good condition. The NG-mixer and NG diaphragm (for specific models) should be saved in case the boiler needs to be converted back to natural gas later. New rubber gaskets provided with the kit must be used when reassembling the gas pipe to the gas valve and mixer.
Preliminary Gas Valve Adjustment: This involves adjusting the gas valve throttle screw based on the boiler model. For models 085, 110, and 110C, the throttle screw needs to be adjusted counter-clockwise by 0.5 turns. For models 150, 199, 150C, and 199C, the adjustment is 2 turns counter-clockwise. After this, the gas supply is turned on, and all piping is tested for leaks.
Gas Line Pressure Test: This critical step involves measuring the gas line pressure to the boiler using a pressure gauge connected to the Line Pressure Test Port. The pressure must fall within the specified range for propane (11 inches w.c. nominal, 8 inches w.c. minimum, and 13 inches w.c. maximum). The manual explicitly states that the boiler gas valve cannot influence or adjust the gas line pressure, which is a function of the gas supply and field-provided parameters like line size and regulator settings.
Combustion Calibration (CO2/CO Adjustment): This is perhaps the most vital part of the conversion. It requires a calibrated combustion analyzer to measure CO2 and CO levels at both maximum and minimum gas flow rates (high and low fan speeds). The boiler is put into a "Test Function" mode to achieve maximum heating power and then minimum DHW power. Adjustments are made to the gas valve's setting screws (screw 4 for maximum gas flow and screw 2 for minimum gas flow) to bring the CO2 levels within the recommended range for propane (9.5 to 11%). The manual warns that minimum gas flow adjustment is very sensitive and that if the CO2 value at minimum power is changed, the maximum gas flow adjustment must be repeated. The CO maximum limit is 175 ppm for propane.
Ending Adjustment: After calibration, the Test Mode is exited, the thermostat is turned down, the DHW draw-off is stopped, all thermostatic valves are reset (for heating boiler applications), the combustion test port plug is reinstalled, and the front cover is reinstalled. A final check for gas leaks is performed.
Rating Plate Update: The certified installer must update the rating plate decal on the appliance to indicate that it has been converted to Propane Gas, including the date of conversion. A separate conversion decal, provided in the kit, must also be filled out with the installer's name and affixed to the boiler cabinet adjacent to the rating plate decal.

Maintenance Features

The conversion process itself is a form of specialized maintenance, ensuring the boiler's longevity and safe operation with a different fuel type. The instructions emphasize several maintenance-related aspects:

Component Inspection: Before securing the LP-Mixer, the O-ring seal between the mixer and blower must be verified to be correctly positioned and in good condition. This prevents gas leaks and ensures proper sealing.
Leak Detection: After initial adjustments and after the entire conversion process, gas leaks must be checked in all piping. This is a critical safety measure.
Combustion Analysis: The requirement to use a calibrated combustion analyzer for CO2 and CO measurements is a key maintenance feature. This ensures that the boiler is operating efficiently and safely, preventing the production of dangerous levels of carbon monoxide. The manual explicitly states that visually looking at the burner does not determine combustion quality, underscoring the necessity of precise analytical tools.
Documentation: Updating the rating plate and affixing the conversion decal serves as a permanent record of the conversion, which is vital for future servicing, inspections, and ensuring that the boiler is always operated with the correct fuel type. This documentation also identifies the qualified service agency responsible for the conversion.
Warning on Carbon Monoxide: The manual includes prominent warnings about carbon monoxide, stressing the importance of proper installation, ventilation, and the use of CO detectors. It also advises against operating the heater if flood-damaged or if the vent system is obstructed. These warnings are crucial for ongoing safety and highlight the importance of regular checks and adherence to installation guidelines.
Saving Original Parts: The instruction to save the original NG-mixer and NG diaphragm is a practical maintenance feature, allowing for a potential future conversion back to natural gas if needed.

Overall, the manual outlines a comprehensive conversion process that integrates installation, calibration, and safety checks, all of which contribute to the long-term, safe, and efficient operation of the NTI boiler on propane gas.