SL 40-399 G3 - Fuel Conversion to Propane (NG to LP) P-Kit 302 If converting from Propane to Natural Gas, order the Natural Gas Conversion Parts Kit (IBC Part # P-303) from your authorized IBC Distributor. Use the Propane Gas conversion parts kit if the fuel source at the site uses Propane and the modulating boiler has been set up (factory fire-tested) to operate with Natural Gas. Check the rating plate on the boiler to see which fuel source the particular boiler has been set up with. Using this conversion kit, a qualified technician will need to: 1. Perform a fuel conversion. 2. Perform a combustion test. 3. Fill in the information required on the fuel conversion labels, and affix them to the boiler after the conversion is completed. 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. The boiler will automatically de-rate the maximum input at a rate of approximately 2% per 1,000 above 4,500. The gas valves zero governor will ensure that the gas:air mixture is not affected at altitude. Included with the Conversion Kit: 1 x LP Mixer Assembly, 399 G3 - Part # 500-114 1 x Orifice - Part # 250-865 1 x Mixing device O-ring Part # 150-073 1 x Gasket, orifice - IBC - Part # 255-035C1 1 x Rating Plate Fuel Overlay - Part # 080-242 1 x Gas Valve Conversion Label - Part # 080-107B and 1 x Installer Identifier Label - Part # 080-244A1 120-273 R2 1
Combustion Test Target Ranges Figure 1 Gas valve and fan The Low Fire (Zero-offset) valve adjustment cap on the gas valve has been factory set. Do not tamper with or adjust this screw in the field. Contact the factory for written instructions if considering field adjustment of the Low Fire (zero offset) adjustment. The High Fire (Gas:Air) ratio adjustment screw is a slotted brass screw to the left of the long brass protrusion on the front of the gas valve. It will have to be adjusted to attain optimum combustion results whenever fuel conversion is undertaken; however, no mixture adjustment shall be performed unless done by a qualified technician using properly functioning and calibrated combustion analyzing equipment. Fuel High Fire Low Fire Co Max PPM Range Target Range Target Natural Gas 9.0 10.0 9.5 8.2 9.2 8.7 < 150 Propane 10.3 11.3 10.8 9.3 10.3 9.8 < 250 Table 1 Combustion test target ranges - CO 2 / Maximum CO Low Fire CO 2 should be at least 0.5% lower than High Fire CO 2. 2
Fuel Conversion Instructions The following procedure must be carried out by a qualified technician. Caution Before you disconnect the electrical power, you must shut off the gas supply. SL 40-399 G3 Model Number Orifice Size 11.2 mm Table 2 Propane Orifice Chart To perform a fuel conversion: 1. Ensure that the gas supply is turned off at the gas shut-off valve. 2. Using a 4 mm hex key, remove the four hex bolts that bolt the gas valve to the gas valve manifold on the venturi mixing device. 3. Remove the O-ring and orifice. Retain the O-ring that goes between the gas valve manifold and the gas valve body. You will need the O-ring in Step 7. 4. the orientation and screw positions of the Phillips head screws that secure the venturi mixing device to the fan. 5. Remove the venturi mixing device from the base of the fan. 6. Attach the fuel-appropriate venturi mixing device to the base of the fan with the three Phillips head screws. 7. Install the O-ring and the orifice between the gas valve body and the venturi mixing device, and then bolt the gas valve to the venturi mixing device with the 4 mm hex bolts. Caution Failure to position the O-ring as indicated will result in a gas leak. 8. Check for gas leaks. Now, carefully follow the procedures on combustion testing and the correct adjustment (see Combustion testing and adjustment on page 4). SL 40-399 G3 - Convert to LP fuel (P-Kit 302) 3
Combustion testing and adjustment Danger A combustion test checks that the gas valve is operating properly in the field. To perform a combustion test, you must be a qualified, trained and licensed gas fitter. Making adjustments to the IBC gas valve without a properly calibrated gas combustion analyzer and by people who are not trained and experienced in its use is forbidden. Failure to use an analyzer can result in an immediate hazard. Model Number SL 40-399 G3 High Fire Input 399 MBH Table 3 Rated input of a converted boiler Normal ignition system sequence of operation: The boiler control, upon a call for heat or DHW, turns on the combustion fan for a 20-second pre-purge, then energizes the spark electrode and gas valve for a 4-second trial for ignition. If the burner does not light, the process is repeated until the burner lights and flame is detected. After 3 trials for ignition, the boiler locks out and will need to be manually reset by clearing the error on the touchscreen controller (Diagnostics > Advanced Diagnostics > Clear Errors). The boiler automatically resets after 60 minutes, if no action is taken. To perform a combustion test and adjustment: 1. Turn off the boiler s gas shut-off valve. 2. With a small (1/8" or 3 mm) flat screwdriver, open the inlet gas supply pressure test port by turning its center-screw 1 full turn counterclockwise. 3. Attach a manometer to the inlet pressure test port and turn on gas to appliance. Static manometer reading should be ideally 7" w.c. for Natural Gas and 11" w.c. for Propane. Minimum and maximum static pressure should be between 5" and 14" w.c. Monitor pressure throughout the commissioning (start-up) procedure. Pressure may drop up to 1" to 2" w.c. at high fire. 4. Before you change the load to manual control, note the load setting. 5. Set the load to manual control, and set the heat-out value to the maximum MBH for the boiler. This load should be large enough to allow the boiler to operate at high fire for over 10 minutes. 4
6. With a combustion analyzer probe in the flue gas test port, check the flue gas reading and adjust the gas:air ratio screw to bring the flue gas to within the parameters indicated in Table 1. 7. Adjust slowly (clockwise) the High Fire (Gas : Air Ratio Adjustment) screw to obtain the correct CO 2 value (see Table 1 ). 8. Make tiny adjustments (may require several turns). Turning the High Fire (Gas : Air Ratio Adjustment) screw clockwise will lean out the flame. Clock the gas meter (see instructions on Page 6) to confirm full maximum rating plate input. Check the measured results with Table 3. 9. Set the heat-out value in manual mode to the minimum MBH for the boiler (see Table 1 ). 10. While the boiler is at Low Fire, compare the combustion reading against the reading in Table 3. The reading should be within the range listed. 11. Restore the load to the previous load type. All the programmed settings will be restored and the load will operate as before. Confirm a smooth ignition sequence. 12. Turn off the gas supply at the gas shut-off valve. 13. Disconnect the power to the boiler. 14. Disconnect the manometer. 15. Close the gas supply test port screw by turning clockwise. 16. Turn on the gas supply shut off valve and test for gas leaks. 17. Restore power to the boiler. Next you must fill in the information and affix the included fuel conversion labels to the boiler in the positions indicated after the conversion is completed. Completing and Affixing the Conversion Labels 1. Fill in the conversion labels (included in the kit) associated with the new fuel type. 2. Place the conversion labels onto the boiler at the positions indicated on Where to Place Conversion Labels on the Boiler on page 7. SL 40-399 G3 - Convert to LP fuel (P-Kit 302) 5
Clocking the Meter (Natural Gas) 1. Turn off all other appliances and pilots. 2. Turn on the boiler and set the boiler to high fire. 3. Ensure the boiler has a large load to heat, so that the boiler will not shut off. 4. With a Stop-Watch, record the number of seconds for the smallest dial to make 1 full revolution. 5. CFH = (3600 x Dial Size) / Seconds. 6. CFH x 1000 (check local Btu content) = Input Btu s. For 2 PSI meters multiply CFH x 1.097 For Metric meters multiply CFH x 35.3 For 2 PSI metric meters multiply CFH x 1.097 x 35.3 For Altitude above 4,500 deduct 2% per 1,000 of altitude from the Input Btu s. 6
Where to Place Conversion Labels on the Boiler SL 40-399 G3 - Convert to LP fuel (P-Kit 302) 7