TECHNICAL SERVICE BULLETIN

Transcription

1 INTERNATIONAL, INC. 159 PARIS AVENUE NORTHVALE, NJ PHONE TECHNICAL SERVICE BULLETIN Date: 08/19/05 Number: Subject: KC1000 LOW NOx CONVERSION KIT INSTRUCTIONS Page 1 of INTRODUCTION The KC1000 Low NOx Conversion Kit, Part No contains all of the assemblies, cables and attaching parts necessary to upgrade a KC1000 Boiler or Water Heater for Low NOx compliance. When so equipped, the Boiler or Water Heater complies with the NOx emission standards outlined in: South Coast Air Quality Management District (SCAQMD), Rule Texas Commission on Environmental Quality (TCEQ), Title 30, Chapter 117, Rule NOTE These Conversion Kit instructions are applicable to all KC1000 units, regardless of the Control System and/or Safety Shutoff Valve (SSOV) installed on your unit. Unless otherwise specified, the descriptions and procedures contained in this Service Bulletin apply to all Natural Gas KC1000 Water Heater and Boiler configurations. If you are not certain of your current unit configuration, contact your nearest AERCO Representative. 1.1 General Description In order to comply with the above-mentioned low NOx emission standards, the existing KC Burner Assembly must be replaced with a new Low NOx Burner Assembly and a Staged Ignition Assembly. In addition, several other assemblies must be modified to ensure low NOx emissions. The Low NOx Conversion procedures provided in this Service Bulletin are divided into the following main categories: Equipment Removal Equipment Modification/Rework Equipment Replacement/Reinstallation Post-Installation Setup and Calibration The procedures in each of these categories are presented in Sections 2 through 5 respectively. The following paragraphs in this Section describe the contents of the Low NOx Conversion Kit and the tools and test equipment required to perform all procedures in this Service Bulletin. 1

2 1.2 Conversion Kit Contents KC1000 Low NOx Conversion Kit, Part No ( ) is available in four configurations, designated - 1, -2, -3 and -4. The -1 and -2 Kits apply to newer KC1000 Water Heaters and Boilers respectively, equipped with Siemens Safety Shutoff Valves (SSOVs) and C-More Control Systems. The -3 and -4 Kits apply to older KC1000 Water Heaters and Boilers respectively, equipped with Honeywell SSOVs. Older KC1000 units may also be equipped with Modular or Digital Control Systems, instead of the C- More Control Systems used on current KC1000 units. The Kit Dash Number column in the following Table indicates which parts are included in each Kit. As this Table shows, only minor differences exist between the contents of the four Kit configurations. Item No. Conversion Kit, Part No ( ) Contents Part No. Kit Dash Number Description All Low NOx Burner Assembly All 5/16-18 x 1-3/4 Long Studs (Qty=6) , -2 Only Staged Ignition Assembly , -4 Only Staged Ignition Assembly All Low NOx Air/Fuel Valve Gas Plate Assembly All Low NOx Air/Fuel Valve Butterfly All Low NOx Gas Regulator Plated Spring All Solenoid Valve Harness All Low NOx Combustion Chamber Liner All Low NOx Igniter Assembly All Low NOx Flame Rod Assembly All Low NOx Conversion Labels Sheet , -3 Only Low NOx Heater Specs. Label , -4 Only Low NOx Boiler Specs. Label 15 GF-111LN or GF-109LN -1 Only or -2 Only Low NOx Heater O & M Manual or Low NOx Boiler O & M Manual 2

3 1.3 Tools and Test Equipment Required The required tools and test equipment are listed in paragraphs and respectively Tools The following tools are required to perform the conversion procedures specified in this Service Bulletin: Wrenches: 3/16, 7/16, 1/2, two 9/16, 5/8, 11/16, 15/16 Vise-Grip Pliers Flat Tip Screwdriver, 1/2 - Inch Blade Phillips Head Screwdriver, No. 3 AERCO Differential Gas Pressure Regulator Adjustment Tool, Part No. GM Test Equipment Following installation of all Conversion Kit items, the following test equipment will be required to perform combustion calibration of the modified KC1000 Boiler or Water Heater using the applicable Operation & Maintenance Manual: Digital Combustion Analyzer Oxygen accuracy to ±0.5 %, carbon monoxide and NOx resolution to 1 ppm. One 16 W.C. Manometer and plastic tubing One 1/4 inch and two 1/8 inch NPT-to-barbed fittings for use with manometers WARNING HIGH VOLTAGE OF 120 VAC IS USED IN KC1000 SYSTEMS. USE EXTREME CARE WHEN ACCESSING CIRCUITS AND ELECTRICAL CONNECTIONS WITHIN THE EQUIPMENT. SERIOUS PERSONAL INJURY OR DEATH MAY OCCUR IF THIS WARNING IS NOT OBSERVED. 2. EQUIPMENT REMOVAL The locations of the major items to be removed from the KC1000 are shown in Figure 1. These items include the existing Burner Assembly, Combustion Chamber Liner, Gas Inlet Pipe and the Air/Fuel Valve. The existing Burner and Combustion Chamber Liner will be replaced with new assemblies provided in the Conversion Kit. The Air Fuel Valve will be modified using the applicable procedures in Section 3. 3

4 NOTE ILLUSTRATION SHOWS KC BOILER WITH COVERS REMOVED. THE LOCATIONS OF THE AFFECTED ITEMS ARE IDENTICAL FOR BOTH KC BOILERS AND WATER HEATERS COMBUSTION CHAMBER LINER AIR/FUEL VALVE CONTROL BOX CONDENSATE DRAIN TUBE I/O BOX BURNER ASSEMBLY GAS INLET PIPE DIFFERENTIAL GAS PRESSURE REGULATOR SSOV LOW GAS PRESSURE SWITCH Figure 1. KC1000 Component Locations Removal of the required items is accomplished as follows: CAUTION DO NOT DISCARD ANY OF THE REMOVED PARTS OR ASSEMBLIES UNLESS IT IS SPECIFICALLY INDICATED THAT THEY WILL NO LONGER BE USED. IT IS RECOMMENDED THAT ALL REQUIRED ITEMS BE REMOVED AS INDICATED IN THE FOLLOWING STEPS PRIOR TO PERFORMING ANY REPLACEMENT PROCEDURES IN SECTION Turn off the gas supply and disconnect AC power from the unit. 2. Remove the top and side sheet metal covers from the unit. 3. At the rear of the unit, disconnect the plastic tubing from the condensate cup to the drain. 4

5 4. Remove the rear covers from the unit. 5. Remove the condensate cup from under the unit and disconnect the condensate drainage tube from the exhaust manifold. 6. Disconnect the flame detector and igniter cable leads from the flame detector and igniter contactor. 7. Remove the ground terminal connection from the Burner by loosening the top screw shown in Figure 2. Slide the connector off the grounding rod. Figure 2. Ground Terminal Location 8. Using a 7/16 inch socket or open end wrench, remove the four 1/4 20 hex nuts on the gas inlet pipe flange at the Burner. See Figure Using two 9/16 inch wrenches, remove the two 3/8 16 hex nuts and bolts on the gas inlet pipe flange at the Air/Fuel Valve (Figure 3). Remove the gas inlet pipe and gaskets from the unit. 10. Loosen the hose clamp on the Air/Fuel Valve side of the valve-to-burner air hose as shown in Figure Using a 1/2 inch socket wrench, remove the six 5/16 18 hex nuts supporting the existing Burner Assembly (Figure 3). 12. Lower the Burner Assembly while sliding the valve-to-burner air hose off the Air/Fuel Valve. Completely remove the Burner from the rear of the unit. 13. Loosen the hose clamp on the removed Burner Assembly inlet and slide the valve-to-burner air hose off the Burner. Retain the hose and clamp. These items will be reinstalled in Section 4. The removed Burner Assembly will be replaced with the new Low NOx Burner provided in the Conversion Kit. 5

6 Figure 3. Burner & Air/Fuel Valve Removal 14. Remove the 8-inch Combustion Chamber Liner from the Heat Exchanger (Figure 4). Since this liner will be replaced, It may be cut or broken to simplify removal. NOTE If difficulty is encountered during removal of the 5/16-18 studs, it may be necessary to Double-Nut the studs to simplify the removal process. 15. Using vise-grip pliers, remove the six 5/16 18 x 1-1/2 long studs used to secure the removed Burner Assembly to the Exhaust Manifold. These studs will be replaced with 1-3/4 studs provided in the Conversion Kit. 16. Disconnect the Air/Fuel Valve wiring harness from the Control Box. 17. Disconnect the two wire leads from the Blower Proof Switch shown in Figure Loosen the hose clamp on the Air/Fuel Valve inlet side of the blower-to-valve air hose shown in Figure Using an 11/16 inch wrench, loosen the two compression fittings securing the feedback tube to the Air/Fuel Valve and Differential Pressure Regulator shown in Figure Using two 9/16 inch wrenches, remove the two 3/8 16 bolts and hex nuts securing the Air Fuel Valve to the Differential Pressure Regulator (Figure 3). 6

7 EXHAUST MANIFOLD INSULATION 1/4-20 SCREW & FENDER WASHER (3 PLACES) COMBUSTION CHAMBER LINER Figure 4. KC1000 With Burner & Air/Fuel Valve Removed Figure 5. Blower Proof Switch 7

8 CAUTION USE CARE WHEN REMOVING THE AIR/FUEL VALVE TO AVOID DAMAGING OR LOSING THE FLANGE O-RING. 21. Completely remove the Air/Fuel Valve from the unit. This assembly will be modified in Section Remove the Exhaust Manifold insulation (Figure 4) by removing the three 1/4-20 screws and fender washers securing it in place. NOTE Current KC1000 units are equipped with Siemens Safety Shutoff Valves (SSOVs). However, some earlier units may be equipped with Honeywell SSOVs. The mounting location of the Low Pressure Gas Switch will differ slightly, depending on the SSOV installed. Refer to Figure 6 (Siemens) or Figure 7 (Honeywell) for the appropriate SSOV installed. 23. Next, refer to Figure 6 (Siemens SSOV) or Figure 7 (Honeywell SSOV) to locate the Low Pressure Gas Switch on the right side of the unit. Disconnect the two wire leads from the switch. 24. For Siemens SSOVs, the Low Pressure gas Switch is installed in the upstream SSOV port using an NPT reducer. For Honeywell SSOVs, the Switch is installed directly in the gas supply inlet pipe. Temporarily remove the Low Pressure Gas Switch as follows: (a) For Siemens SSOVs, remove the switch (with NPT reducer attached) from the upstream SSOV port using a 5/8 wrench. (b) For Honeywell SSOVs, remove the switch from the tapped hole in the gas supply inlet pipe using a 1/2 wrench. The Low Pressure Gas Switch will be reinstalled in Section 4. 8

9 Figure 6. Low Pressure Gas Switch Location With Siemens SSOV Installed Figure 7. Low Pressure Gas Switch Location With Honeywell SSOV Installed 25. This completes the equipment removal procedures for the KC Boiler or Water Heater. Proceed to the Modification/Rework procedures in Section 3. 9

10 3. EQUIPMENT MODIFICATION/REWORK The equipment items to be modified are the Air/Fuel Valve and Differential Gas Pressure Regulator. The Air/Fuel Valve was removed from the unit in Section 2 of this Service Bulletin. The Differential Gas Pressure Regulator can be modified in place without removal. The modification procedures for these items are presented in paragraphs 3.1 and 3.2 which follow. 3.1 Air/Fuel Valve Modification The modifications to be made to the Air/Fuel Valve consist of replacing the lower gas plate and the air valve butterfly with the replacement items contained in the Conversion Kit. Place the Air/Fuel Valve on a workbench and proceed as follows: 1. Rotate the Air/Fuel Valve butterfly so that the valve is in the fully closed position. 2. Using a 7/16 inch socket or wrench, remove the four 1/4-20 hex head machine screws securing the lower portion of the Air/Fuel Valve body to upper valve body as shown in Figure 8. CAUTION DO NOT ROTATE THE VALVE BUTTERFLY FROM THE FULLY CLOSED POSITION AFTER SEPARATING THE UPPER AND LOWER VALVE BODY. 3. Separate the upper and lower portions of the valve body to access the gas plate as shown in Figure Remove the existing gas plate with upper/lower O-rings from the Air/Fuel Valve. 5. Obtain the replacement low NOx gas plate and O-rings from the Conversion Kit. Apply O-ring lube (Dow-Corning Compound #111, or equiv.) to the replacement O-rings and install them in the grooves on the gas plate.(figure 10). 6. Refer to the cut-away view in Figure 9. Ensure that the valve components are positioned as shown in the upper valve body. 7. Position the low NOx gas plate so that the plate slot engages the locating pin in the upper valve body (Figure 9). Also, ensure that the shutter stop pin (Figures 9 and 10) is facing the upper portion of the valve body. 8. Apply LocTite No. 242 (Blue), or equivalent, to the threads of the four 1/4-20 hex head machine screws removed in step 2. Reassemble and secure the lower and upper portions of the valve body by alternately tightening the four 1/4-20 machine screws. 10

11 STEPPER MOTOR COVER AIR INLET A 1/4-20 HEX HEAD SCREWS (4) VALVE BODY (UPPER) VALVE BODY (LOWER) GAS INLET A (SEE FIGURE 9) Figure 8. Air/Fuel Valve Modification 11

12 VALVE SHAFT SPRING RING- SHAFT SEAL SHAFT SEAL- BACKUP WASHER RETAINING RING PRE-LOAD SPRING SHAFT DRIVE PIN SHUTTER STOP PIN GAS VALVE SHUTTER GAS PLATE O-RINGS (2) FUEL OUTLET PLATE LOCATING PIN FUEL INLET GAS PLATE VIEW A - A Figure 9. Air/Fuel Valve Partial Cross-Sectional View Figure 10. Low NOx Gas Plate 12

13 9. Next, remove the #8-32 screw securing the existing air butterfly to the Air/Fuel Valve shaft (Figure 11) and remove the butterfly. 10. Apply a small amount of LocTite No. 222 (purple) to the #8-32 screw threads and install the new air butterfly and flat washer provided in the Conversion Kit onto the shaft. Center the butterfly so that there is equal clearance between the valve bore and the edges of the butterfly. 11. Manually open and close the butterfly several times to ensure that it is properly positioned on the shaft with equal clearances around the valve bore 12. This completes the Air/Fuel Valve modifications. The modified Air/Fuel Valve is now ready to be reinstalled using the procedures in Section 4. Figure 11. Air Butterfly Replacement 3.2 Differential Gas Pressure Regulator Modification The modification to be made to the Differential Gas Pressure Regulator consist of removing the exist spring and replacing it with the new plated spring provided in the Conversion Kit. Proceed as follows: 1. Remove the cap on the Differential Gas Pressure Regulator (Figure 12). 2. Remove the adjustment screw and the installed regulator spring from the Differential Gas Pressure Regulator. 3. Install the replacement plated spring provided in the Conversion Kit. 13

14 IMPORTANT It is important that the adjustment screw be installed to a depth of 2 inches from the top of the regulator housing. This will simplify combustion calibration of the unit after all low NOx modifications are completed. 4. Replace the adjustment screw and rotate the screw clockwise to a depth of 2 inches from the top of the regulator housing. 5. Replace the regulator cap and gasket and ensure that the cap is firmly secured. This completes the modification of the Differential Gas Pressure Regulator. REGULATOR CAP CAP GASKET ADJUSTMENT SCREW SPRING (PARTIALLY REMOVED) DIFFERENTIAL GAS PRESSURE REGULATOR Figure 12. Differential Gas Pressure Regulator Modification 14

15 4. EQUIPMENT REPLACEMENT & REINSTALLATION The parts provided in the Low NOx Conversion Kit will differ slightly, depending on whether the KC1000 is equipped with a Siemens SSOV (-1 or -2 Kit) or a Honeywell SSOV (-3 or -4 Kit). See paragraph 1.2 for kit contents. Following removal and/or modification of all the required parts and assemblies, replace or reinstall these items as follows: NOTE Unless otherwise specified, the following steps apply to all KC1000 Boilers and Water Heaters, regardless of the type of SSOV installed. 1. Install the six new 5/16-18 x 1-3/4 studs provided in the Kit in the Exhaust Manifold as follows: (a) Apply LocTite 620 (or equivalent) to the manifold-end of the stud threads. (b) Thread the ends of the studs into the tapped holes in the bottom of the Exhaust Manifold as shown in Figure 13. Ensure that they are fully inserted and secure. These studs will be used to secure the new Low NOx Burner to the manifold. CAUTION THE EXHAUST MANIFOLD OPENING IS SLIGHTLY TAPERED. THERE- FORE, USE CARE WHEN INSTALLING THE COMBUSTION CHAMBER LINER TO AVOID DAMAGE. 2. Position and install the new 2 inch Combustion Chamber Liner using the steps shown in Figure 14. Position the Liner so it is flush with the bottom of the Exhaust Manifold (Figure 13) Figure 13. Exhaust Manifold Studs and Combustion Chamber Liner Location 15

16 Figure 14. Installation of Combustion Chamber Liner NOTE The next item to be installed is the new Low NOx Burner Assembly provided in the Conversion Kit. To simplify installation and avoid component damage, it will be necessary to temporarily remove several components from the Low NOx Burner Assembly. 3. Remove the new Low NOx Burner from the Conversion Kit. Refer to Figure 15 and temporarily remove the following components and assemblies from the Low NOx Burner: (a) Remove the Igniter and Flame Detector Assemblies. (b) Remove the 1/8 NPT nipple and the 1/4 O.D. tubing from the Burner Shell. (c) Loosen the top screw on the two-way connector and slide it off the ground stud. (d) Remove the hex nut from the ground stud. (e) Remove the two bolts securing the Burner Head to the Shell. (f) Separate the Burner Head from the Burner Shell. (g) Proceed to step 4. 16

17 Figure 15. Low NOx Burner Components 17

18 4. Due to space limitations, the new Low NOx Burner Head and Shell must be temporarily separated as described in the previous step and installed as follows: (a) First, insert the Burner Head inside the Heat Exchanger. (b) While hold the Head in the raised position, place the Fiber Frax Gasket and Burner Shell under the unit. (c) Lower the Burner Head and align it so that the ground stud shown in Figure 16 is aligned with the hole in the Shell flange. Also, ensure that the Shell air inlet is positioned as shown. (d) Raise the complete Low NOx Burner Assembly and secure it to the Heat Exchanger studs using the six 5/16-18 hex nuts removed from the old burner. (e) Next, install the 1/4 O.D. tube and 1/8 NPT nipple (3 long) as shown in Figure 17. Ensure that the 1/4 tube is inserted into the staged ignition orifice piece. Thread the nipple into the tapped hole in the bottom of the Burner Shell. (f) Refer to Figure 19 and remove the 1/8 street elbow from the outlet end of the Staged Ignition Assembly provided in the Conversion Kit. NOTE The Staged Ignition Assembly part number provided in the Low NOx Conversion Kit will depend on whether the unit being converted is equipped with a Siemens or a Honeywell SSOV. Kits and -2 contain Staged Ignition Assembly part no for use with Siemens SSOVs. Kits and -4 contain Staged Ignition Assembly part no for use with Honeywell SSOVs. (g) Attach the street elbow to the 3 nipple and securely tighten the nipple to the Burner Shell. 18

19 IGNITION TRANSFORMER EXHAUST MANIFOLD 2" COMBUSTION CHAMBER LINER 5/16-18 X 1-3/4" STUDS (6) STAGED IGNITION ORIFICE PIECE BURNER HEAD GROUND STUD FIBER FRAX GASKET AIR INLET BURNER SHELL Figure 16. Low NOx Burner Installation 19

20 Figure 17. Installation of Staged Ignition Tube and Nipple 5. Reinstall the Exhaust Manifold insulation (Figure 4) using three 1/4-20 screws and fender washers. 6. Reinstall the modified Air/Fuel Valve (Figure 18) as follows: (a) Connect the blower-to-valve air hose and clamp at the Air/Fuel Valve inlet as shown in Figure 18. Do Not tighten the hose clamp at this time. (b) Ensure that the flange O-ring is installed between the Air/Fuel Valve gas inlet flange and the Differential Gas Pressure Regulator outlet flange. (c) Using two 9/16 wrenches, secure the Air/Fuel Valve to the Differential Gas Pressure Regulator with two 3/8-16 bolts and hex nuts. (d) Tighten the hose clamp on the blower-to-valve air hose at the Air/Fuel Valve inlet. (e) Using an 11/16 wrench, secure the feedback tube between the Air/Fuel Valve and Regulator by tightening the two compression fittings (Figure 18). (f) Reconnect the two wire leads to the Blower Proof Switch. (g) Reconnect the Air/Fuel Valve wiring harness to the Control Box. 7. Install the Gas Inlet Pipe (Figure 18) between the Air Fuel Valve gas outlet and the Low NOx Burner gas inlet as follows: (a) Insert flange O-rings in the inlet and outlet sides of the gas pipe. (b) Position the Gas Inlet Pipe so it is aligned with the 1/4-20 studs on the Burner and the Air/Fuel Valve gas outlet flange. 20

21 (c) Secure the Gas Inlet Pipe to the Air/Fuel Valve with two 3/8-16 bolts and hex nuts. (d) Secure the Pipe to the Burner with four 1/4-20 hex nuts. (e) Reinstall the valve-to-burner air hose and clamps between the Air/Fuel Valve outlet and Burner inlet. Tighten both clamps. NOTE Figure 18 shows the installation details for both the modified Air/Fuel Valve and the Gas Inlet Pipe. Install these items in the order specified in steps 6 and 7. Figure 18. Air/Fuel Valve and Gas Inlet Pipe Installation 8. The next item to be installed is the new Staged Ignition Assembly shown in Figure 19. As this Figure shows, there are two versions of this assembly; one for use with Siemens SSOVs (part no ) and one for use with Honeywell SSOVs (part no ). Mechanically, the outlet side of both Staged Ignition Assembly models connect to the Low NOx Burner. However, the inlet side connections of Staged Ignition Assembly models differ as follows: Staged Ignition Assembly (used with Siemens SSOVs) inlet side connects to the downstream port directly on the Siemens SSOV. Staged Ignition Assembly (used with Honeywell SSOVs) inlet side connects to the port on the gas cock located downstream of the Honeywell SSOV. Electrically, the solenoid valve on each of these assemblies is connected to the KC wiring harness power leads going to the ignition transformer. The mechanical connections are provided in steps 9, 10 and 11. The electrical connections are provided in step

22 Figure 19. Staged Ignition Assemblies Part No &

23 NOTE The 1/8 street elbow shown in Figure 19 was previously removed in step 4(f) and attached to the 3 nipple on the Low NOx Burner Shell. 9. The outlet side connection for the Staged Ignition Assembly is the same regardless which type of SSOV (Siemens or Honeywell) is installed on the KC1000. Proceed as follows: (a) Loosen the 1/4 NPT union on the Staged Ignition Assembly (Figure 19) provided in the kit and separate the 9 nipple and 1/4 to 1/8 reducing coupling from the assembly. (b) Connect the reducing coupling to the 1/8 street elbow already attached to the Low NOx Burner (Figure 20). GROUND CONNECTOR GAS INLET PIPE 1/8" NPT NIPPLE (3" LONG) STREET ELBOW REDUCING COUPLING 1/4" NPT NIPPLE (9" LONG) Figure 20. Staged Ignition Assembly Outlet Side Connection 10. The inlet side connection for the Staged Ignition Assembly depends on which type of SSOV (Siemens or Honeywell) is installed in the KC1000. Proceed as follows: (a) Refer to Figure 19. For the Staged Ignition Assembly provided in the kit, disconnect the 1/2 flex gas hose at the inlet side from the 1/2 to 1/4 reducing coupling shown in Figure 19 for the applicable assembly. 23

24 (b) If the KC1000 is equipped with a Siemens SSOV, remove the 1/4 NPT plug from the downstream port on the SSOV. Connect the inlet side (flex gas hose and nipple) of the Staged Ignition Assembly (part no ) to this 1/4 NPT port as shown in Figure 21. LOW PRESSURE GAS SWITCH WITH NPT REDUCER GAS INLET BLOWER SSOV STAGED IGNITION ASSY FLEX GAS HOSE CONNECT TO 1/4" NPT DOWNSTREAM PORT KC1000 PARTIAL TOP VIEW Figure 21. Staged Ignition Assembly Inlet Connection For Siemens SSOV (c) For a Honeywell SSOV, remove the 1/8 plug from the inboard side of the gas cock shown in Figure 22. Connect the inlet side of the Staged Ignition Assembly (part no ) containing the 5 long 1/8 NPT nipple to the gas cock port. 24

25 Figure 22 Staged Ignition Assembly Inlet Connection For Honeywell SSOV 11. After the Staged Ignition outlet and inlet connections are completed, reconnect the 1/4 NPT union at the Burner side (outlet) and the flex gas hose at the SSOV side (inlet) to the remaining assembly components (Figure 19). 12. The Solenoid Valve on the Staged Ignition Assembly is electrically connected to the Ignition Transformer power leads using the 2-Wire Solenoid Valve Harness provided in the Conversion Kit (Figure 23). Proceed as follows: (a) Connect the two Solenoid Valve power leads to the FASTON terminals of the wiring harness. (b) Remove the cover on the Ignition Transformer. (c) Refer to Figure 23 and remove the two wire nuts connecting power leads 140 and 141 to the Ignition Transformer. Connect the two stripped Solenoid harness leads to power leads 140 and 141 and the Transformer leads as shown. (d) Resecure the wiring connections using the wire nuts. (e) Replace the cover on the Ignition Transformer. (f) Connect the Solenoid Valve Ground lead to the Ground connector on the Low NOx Burner Shell flange (Figure 20). 25

26 13. Next, install the Igniter and Flame Detector in the Low NOx Burner (Figure 24) as follows: (a) Prior to installing the Igniter in the Low NOx Burner, a conductive anti-seize compound MUST be applied to the Igniter threads. (b) Install the Igniter at the location shown in Figure 24. Do Not over-tighten. (c) Connect the Igniter cable from the Ignition Transformer. (d) Install the Flame Detector at the location shown in Figure 24. Do Not over-tighten. (e) Reconnect the Flame Detector lead. Figure 23. Solenoid Valve Wiring Harness and Connections 26

27 Figure 24. Igniter and Flame Detector Installation 14. Reinstall the Low Pressure Gas Switch shown in Figure 6 (Siemens SSOV) or Figure 7 (Honeywell SSOV). Reconnect the two switch wire leads. There is no polarity to observe when reconnecting these leads. 15. Refer to Figure 25 and install the condensate drain components at the rear of the unit as follows: (a) Attach the 1-3/4 O.D. condensate drain hose to the exhaust manifold (Figure 25) and insert the hose into the condensate cup. Allow the cup to rest on the floor directly beneath the condensate drain. (b) Connect a length of 3/4 tubing to the condensate cup drain tube and route it to a floor drain. 27

28 Figure 25. Condensate Drain Assembly Location 16. Prior to proceeding to the next step, check to ensure that the igniter, flame detector and ground leads are secure on the Low NOx Burner. Also, check to ensure that the ball valve in the Staged Ignition Assembly (Figure 19) is in the open position. 17. Replace the rear covers, top cover and side panels on the unit. 18. Attach the appropriate Low NOx labels to the unit as follows: (a) Attach the SCAQMD/TCEQ LOW NOx label to the front of the unit directly beneath the For parts replacement label as shown in Figure 26. (b) Attach the appropriate Heater or Boiler UL Label and Specification Label to the front of the unit (Figure 26). (c) On the left side of the unit, attach the Igniter & Flame Detector Replacement label over the currently installed replacement label at the location shown in Figure

29 GAS-FIRED BOILER FOR USE WITH INTEGRAL CONTROLS INTENDED FOR USE WITH UL LISTED SPECIAL GAS VENT MANUFACTURERS FOR USE WITH CATEGORY INSTRUCTIONS III OR IV FOR GAS FURTHER APPLIANCES VENTING WITH DETAILS. For parts assistance during normal business hours call your local sales representative or... Aerco International at Specifications Temp. Rise (F) 99% 86% 7% GPH Net Input. Net Output. ASME Maximum Working Pressure... Electrical Requirements.. Standby Power Consumption... Adjustable Control Range... Maximum Continuous Water Flow... Water Pressure Drop... Water Volume... Gas Pressure Requirements... FIRING RATE % 30 GPM ,000,000 BTU/Hr 930,000 BTU/Hr F 120/1/60 20 AMP 40 watts 100F to 195F GPM 23 gallons " WC full load 14" WC maximum static U L Aerco KC Gas Fired Hot Water Boiler Aerco KC Gas Fired Hot Water Boiler INVERSE EFFICIENCY CURVE THIS PRODUCT COMPLIES WITH NOx EMISSIONS STANDARDS OUTLINED IN SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT ( SCAQMD ) RULE AND TEXAS COMMISION ON ENVIRONMENTAL QUALITY ( TCEQ ), TITLE 30, CHAPTER 117, RULE , WHEN INSTALLED AND OPERATED IN ACCORDANCE WITH AERCO INSTALLATION, OPERATION, & MAINTENANCE INSTRUCTIONS. INTERNATIONAL INC. Specifications Net Input... 1,000,000 BTU/Hr Net Output ,000 to 930,000 BTU/Hr ASME Maximum Working Pressure F Electrical Requirements /1/60 20 AMP 50F to 220F 25 GPM Water Maximum Pressure Water Flow GPM Drop GPM 23 gallons 9.5" WC full load 14" WC maximum static OR BOILER Aerco KC Gas Fired Commercial Water Heater Recovery Capacity HEATER PARTIAL FRONT VIEW Figure 26. Low NOx Labels Front View 29

30 Figure 27. Low NOx Labels Side View 19. This completes replacement or reinstallation of all required parts and assemblies. Proceed to Section 5 - Post-Installation Setup and Calibration. 30

31 5. POST-INSTALLATION SETUP AND CALIBRATION Following installation of all Low NOx Conversion Kit items, it will be necessary to adjust several operating parameters using the unit s Control System menus. In addition, combustion calibration procedures MUST be performed to ensure Low NOx compliance, prior to placing the unit into service. The procedures in this section are divided into the following main categories: Low NOx Operating Parameter Menu Changes Combustion Calibration Setup Combustion Calibration Procedures for Units With C-More or Modular Control Systems Combustion Calibration Procedures for Units With Digital (CCC) Control Systems Unit Reassembly These procedures are provided in paragraphs 5.1 through 5.5 respectively. For more detailed information on the operation of your KC1000 unit, refer to the applicable Operation & Maintenance Manual for the installed Control System as follows: Unit C-More Control System Modular Control System Digital (CCC) Control System KC1000 Boiler GF-109LN GF-106 GF-102 KC1000 Heater GF-111LN GF-105 GF-101 NOTE If the KC1000 is equipped with an older style Digital (CCC) Control System, no menu changes are required. 5.1 Control System Menu Changes for Low NOx Operation If the KC1000 is equipped with either a C-More or Modular Control System, several menu changes may need to be made to ensure Low NOx compliance. These changes will depend on which type of control system is installed and whether the unit is a boiler or water heater Post-Purge Timeout For C-More Control System If the unit is equipped with a C-More Control System, adjust the Post-Purge Timer in the Factory Menu to 10 seconds as follows: 1. Apply external AC power to the unit. 2. Set the Control Box ON/OFF switch to OFF. 3. Access the Password entry in the Setup menu. 4. Enter and store the Factory Password (2807). Password 3 will be displayed indicating that the valid Factory password has been entered. 5. Next, scroll through the Factory Menu until Post Purge Timer is displayed. 6. Set the Post Purge Timer menu option to 10 sec. and store the entry. 31

32 7. This completes the Post Purge Timer menu setting. 8. If the unit is a Water Heater, go directly to paragraph (Breakpoints) before the entered Factory Password times out (after 1 hour). If the unit is a Boiler, no further menu changes are required. NOTE The Breakpoint Adjustment procedures specified in paragraph apply only to KC1000 Water Heaters containing either a C-More or Modular Control System Water Heater Breakpoint Adjustments The water heater breakpoint settings for a Low NOx KC1000 are different than the breakpoints for a standard unit. Therefore, the appropriate menu items must be adjusted. For C-More Control Systems, the breakpoints are adjusted for fire rate increments of 10% using the Tuning Menu. For Modular Control Systems, the breakpoints are adjusted using the Secondary Menu. Adjust the breakpoints to the values shown in the following Table for the firing rates shown: IMPORTANT Prior to adjusting the breakpoint settings shown in the following Table, ensure that the Water Heater active setpoint is set to 130 F. Following completion of the breakpoint adjustments, the active setpoint temperature can be readjusted if necessary. Firing Rate Water Heater Breakpoint Settings For Low NOx C-More Display Modular Display Required Breakpoint 100% Breakpoint At 100% bp A 64 F 90% Breakpoint At 90% bp 0 63 F 80% Breakpoint At 80% bp 9 66 F 70% Breakpoint At 70% bp 8 74 F 60% Breakpoint At 60% bp 7 83 F 50% Breakpoint At 50% bp 6 93 F 40% Breakpoint At 40% bp F 30% Breakpoint At 30% bp F 20% Breakpoint At 20% bp F 10% Breakpoint At 10% bp F 0% Breakpoint At 0% bp F 32

33 5.2 Combustion Calibration Setup Prior to performing Combustion Calibration procedures in paragraph 5.3 or 5.4, the unit must be set up as follows: Installing The Supply Gas Manometer 1. Close the manual gas supply valve upstream of the unit. 2. Refer to Figure 28 and remove the 1/4 or 1/8 NPT pipe plug from the port on the inlet side of the Siemens or Honeywell SSOV. 3. Install a barbed fitting into the pipe plug tapping. 4. Attach one end of a length of plastic tubing to the barbed fitting and one end to the 16" W.C. manometer. Figure 28. Installation of Supply Gas Manometer Preparing the Flue Vent Probe Hole 1. If the unit has been installed using the recommended AL29-4C vent, there will be a 3/8 hole, 18 to 24 above the exhaust manifold. The outer vent section, that covers vent connections, must be loosened and moved to uncover the hole (see Figure 29). 2. If so equipped, adjust the stop on the combustion analyzer probe so that it extends into the flue gas flow without hitting the opposite wall of the flue. Do not insert the probe at this time. 33

34 Figure 29. Analyzer Probe Hole Location Installing The Differential Regulator Adjustment Tool 1. Remove the cap from the differential pressure regulator (see Figure 30). 2. Place the gasket from the regulator cap onto the regulator adjustment tool. 3. Prior to Installing the tools on the regulator, pull up the tool's screwdriver blade. Then, thread the tool into the regulator. 4. Engage the tool s screwdriver blade into the regulator s adjustment screw slot. Figure 30. Regulator Adjustment Tool Installation 34

35 5.3 Combustion Calibration For Units With C-More or Modular Control Systems The Combustion Calibration procedures for KC1000 Boilers or Water Heaters equipped with either C- More or Modular Control Systems are virtually identical. Using the following procedures will minimize readjustment of combustion. NOTE For a review of the control panel operating procedures for the installed control system, refer to Section 3 of the appropriate O & M Manual listed in paragraph Open the supply and return valves to the unit and ensure that the system pumps are running. Open the gas supply valve(s) to the unit. 2. If a lockup style regulator is installed as a gas supply regulator, adjust the gas supply until a reading of 12 W.C. static pressure is obtained. 3. Set the ON/OFF switch to the OFF position. Turn on AC power to the unit. 4. Set the unit to the Manual Mode. 5. Adjust the firing rate to 0%. 6. Set the ON/OFF switch to ON. 7. Change the firing rate to 25%. This will put the unit in the starting sequence. NOTE On initial start-up, or return to service from a fault condition, the unit will remain at a 29% firing rate for two-minutes, although the control signal may indicate a greater input. 8. Following the warm-up period, increase the firing rate in 20% increments while monitoring the gas pressure after every increase. If gas pressure dips below 9.5 W.C. for FM gas trains and 9.9 for IRI gas trains at any input firing rate percentage, stop and raise the pressure. Once 100% is reached, adjust the gas pressure for 9.5 (FM) W.C. or 9.9 W.C. (IRI). NOTE If 9.5 W.C. for FM gas trains or 9.9 W.C. for IRI gas trains cannot be obtained at the 100% firing rate, it will be necessary to stop calibration and contact the local AERCO representative in your area. Running the unit on insufficient gas pressure will void the warranty. 9. Once 9.5 W.C. or 9.9 W.C. is set at the 100% level change the firing rate to 30%. Insert the combustion analyzer probe into the stack. 35

36 NOTE Always approach a firing rate percentage from the same direction, (i.e., 100% to 30%, 30% to 20%, etc.). Whenever going to an increased firing rate from below (i.e., 20% to 30%), first go above and then back down to the desired firing rate. This is necessary due to hysteresis in the air/fuel stepper motor. Hysteresis causes the air/fuel valve to stop in a slightly different position if the firing rate percentage is approached from below or above. This results in a difference in oxygen readings for the same firing rate percentage causing unnecessary recalibration. 9. Allow enough time for the combustion analyzer to settle. Compare the measured oxygen level to the oxygen range for intake air temperature in Table 1. Also, ensure that the carbon monoxide (CO) and nitrogen oxide (NOx) readings do not exceed the values shown. Table 1 Combustion Oxygen Levels for a 30% Firing Rate Inlet Air Temp Oxygen (±0.2%) Carbon Monoxide *NOx 40 F 6.7 % <100 ppm <23.8 ppm 50 F 6.5 % <100 ppm <24.1 ppm 60 F 6.3 % <100 ppm <24.4 ppm 75 F 6.0 % <100 ppm <24.9 ppm 85 F 5.7 % <100 ppm <25.4 ppm 90 F 5.6 % <100 ppm <25.6 ppm 100 F 5.4 % <100 ppm <25.9 ppm *Tabulated data are uncorrected ppm NOx values and will be less than or equal to 30 ppm of NOx when corrected to 3% oxygen. 10. If the measured oxygen level, CO and NOx emissions are within the ranges shown in Table 1, no adjustment is necessary. Proceed to step If the measured oxygen level is below the range in Table 1, rotate the differential regulator adjustment tool counterclockwise 1/4 to 1/2 revolution to decrease gas flow. 12. Wait for the combustion analyzer to settle, then compare the new oxygen reading to Table 1. Repeat adjustment until oxygen is within the specified range. 13. If the measured oxygen level is above the oxygen range in Table 1, rotate the differential regulator adjustment tool clockwise 1/4 to 1/2 revolution to increase gas flow. 14. Wait for the analyzer reading to settle, then compare the new reading to Table 1. Repeat adjustment until oxygen is within the specified range. NOTE Adjust only the differential regulator at 30% control signal; do not adjust the air shutter. 15. Once the oxygen level is within the specified range at 30%, change the firing rate to 16%. 36

37 16. Oxygen levels at the 16% firing rate should be as shown in Table 2. Also, ensure that the CO and NOx readings do not exceed the values shown. No adjustment should be necessary. Contact the Factory if the oxygen, CO or NOx levels are not within the specified ranges. Table 2 Combustion Oxygen Levels for a 16% Firing Rate Inlet Air Temp Oxygen (± 0.2%) Carbon Monoxide *NOx 40 F <10% <100 ppm <20 ppm 50 F <10% <100 ppm <20 ppm 60 F <10% <100 ppm <20 ppm 75 F <10% <100 ppm <20 ppm 85 F <10% <100 ppm <20 ppm 90 F <10% <100 ppm <20 ppm 100 F <10% <100 ppm <20 ppm *Tabulated data are uncorrected ppm NOx values and will be less than or equal to 30 ppm of NOx when corrected to 3% oxygen. 17. Change the firing rate to 100%. After the combustion analyzer has settled, compare the measured oxygen level with the levels in Table If the measured oxygen reading is below the oxygen range in Table 3, loosen the two bolts that secure the inlet air shutter to the unit using a 7/16 wrench (see Figure 31). Open the shutter 1/4 to 1/2 to increase the oxygen level, then tighten the nuts. 19. Wait for the analyzer to settle then compare the new oxygen reading to Table 3. Repeat the inlet air shutter adjustment until the oxygen is within the specified range. Also, ensure that the CO and NOx emissions do not exceed the values shown. Firmly tighten the inlet air shutter locking nuts when finished. Table 3 Combustion Oxygen Levels for a 100% Firing Rate Inlet Air Temp Oxygen (±0.2%) Carbon Monoxide *NOx 40 F 8.8 % <100 ppm <20.3 ppm 50 F 8.1 % <100 ppm <21.4 ppm 60 F 7.5 % <100 ppm <22.5 ppm 75 F 6.5 % <100 ppm <24.1 ppm 85 F 5.8 % <100 ppm <25.3 ppm 90 F 5.3 % <100 ppm <26.1 ppm 100 F 4.8 % <100 ppm *Tabulated Data are uncorrected ppm NOx values and will be less than or equal to 30 ppm of NOx when corrected to 3% oxygen. 37

38 Figure 31. Air Shutter Locking Nut Location NOTE At 30% firing rate, adjust only the differential pressure regulator. At 100% firing rate, adjust only the inlet air shutter. 20. If the measured oxygen reading is above the oxygen range in Table 3, loosen the two 7/16" locking nuts securing the inlet air shutter. Close the air shutter 1/4 to 1/2 to decrease the oxygen level and tighten the two nuts. 21. Allow the analyzer to settle then compare the new oxygen reading to Table Repeat the adjustment until the oxygen is within the specified range. Also, ensure that the CO and NOx readings do not exceed the values shown. Firmly tighten the inlet air shutter locking nuts when finished. NOTE Adjust the inlet air shutter only at 100% firing rate. Do not adjust the differential pressure regulator. 23. Change the firing rate to 30%. Allow time for the combustion analyzer to settle. Check the measured oxygen level, CO and NOx emissions to ensure that they are still within the ranges shown in Table Continue these procedures until all oxygen levels are within the ranges specified in Tables 1, 2 and Record all readings on the AERCO start-up sheet provided with each unit. Proceed to paragraph 5.5 when all natural gas combustion calibration procedures are completed. 38

39 5.4 Combustion Calibration For Units With Digital (CCC) Control Systems The Combustion Calibration procedures for KC1000 Boilers or Water Heaters equipped with older style Digital (CCC) Control Systems differ from those used for C-More or Modular Control Systems. The primary difference is that the combustion readings are checked at different low and mid-range fire rates. In addition, the Control Panel display shows the manual fire rate in % for KC Boilers and in Volts (1.0 to 5.0) for KC Water Heaters. Using the following procedures will minimize readjustment of combustion. NOTE For a review of the control panel operating procedures for the installed control system, refer to Section 3 of GF-101 (Water Heater) or GF-102 (Boiler). 1. Open the supply and return valves to the unit and ensure that the system pumps are running. Open the gas supply valve(s) to the unit. 2. If a lockup style regulator is installed as a gas supply regulator, adjust the gas supply until a reading of 12 W.C. static pressure is obtained. 3. Set the unit to the MANUAL mode. 4. With the display showing the Power Level, rotate the MANUAL adjustment to display 25% (Boiler) or 2.0 volts (Water Heater). 5. Press the green ON button if the unit is not already ON. NOTE On initial start-up, or return to service from a fault condition, the unit will remain at a 29% firing rate for two-minutes, although the control signal may indicate a greater input. In the following steps and Tables, firing rates for KC1000 Boilers are shown in % and the corresponding firing rates for Water Heaters are shown in parentheses in volts (V). 6. Following the warm-up period, increase the firing rate in 25% (1.0V) increments while monitoring the gas pressure after every increase. If gas pressure dips below 9.5 W.C. for FM gas trains and 9.9 for IRI gas trains at any input firing rate percentage, stop and raise the pressure. Once 100% (5.0V) is reached, adjust the gas pressure for 9.5 (FM) W.C. or 9.9 W.C. (IRI). NOTE If 9.5 W.C. for FM gas trains or 9.9 W.C. for IRI gas trains cannot be obtained at the 100% firing rate, it will be necessary to stop calibration and contact the local AERCO representative in your area. Running the unit on insufficient gas pressure will void the warranty. 7. Once 9.5 W.C. or 9.9 W.C. is set at the 100% (5V) level, change the firing rate to 25% (2.0V). Insert the combustion analyzer probe into the stack. 39

40 NOTE Always approach a firing rate percentage from the same direction, (i.e., 100% to 25%, 25% to 20%, etc.). Whenever going to an increased firing rate from below (i.e., 25% to 30%), first go above and then back down to the desired firing rate. This is necessary due to hysteresis in the air/fuel stepper motor. Hysteresis causes the air/fuel valve to stop in a slightly different position if the firing rate percentage is approached from below or above. This results in a difference in oxygen readings for the same firing rate percentage causing unnecessary recalibration. 8. Allow enough time for the combustion analyzer to settle. Compare the measured oxygen level to the oxygen range for intake air temperature in Table 4. Also, ensure that the carbon monoxide (CO) and nitrogen oxide (NOx) readings do not exceed the values shown. Table 4 Combustion Oxygen Levels for a 25% (2.0V) Firing Rate Inlet Air Temp Oxygen (±0.2%) Carbon Monoxide *NOx 40 F 6.7 % <100 ppm <23.8 ppm 50 F 6.5 % <100 ppm <24.1 ppm 60 F 6.3 % <100 ppm <24.4 ppm 75 F 6.0 % <100 ppm <24.9 ppm 85 F 5.7 % <100 ppm <25.4 ppm 90 F 5.6 % <100 ppm <25.6 ppm 100 F 5.4 % <100 ppm <25.9 ppm *Tabulated data are uncorrected ppm NOx values and will be less than or equal to 30 ppm of NOx when corrected to 3% oxygen. 9. If the measured oxygen level, CO and NOx emissions are within the ranges shown in Table 4, no adjustment is necessary. Proceed to step If the measured oxygen level is below the range in Table 4, rotate the differential regulator adjustment tool counterclockwise 1/4 to 1/2 revolution to decrease gas flow. 11. Wait for the combustion analyzer to settle, then compare the new oxygen reading to Table 4. Repeat adjustment until oxygen is within the specified range. 12. If the measured oxygen level is above the oxygen range in Table 4, rotate the differential regulator adjustment tool clockwise 1/4 to 1/2 revolution to increase gas flow. 13. Wait for the analyzer reading to settle, then compare the new reading to Table 4. Repeat adjustment until oxygen is within the specified range. NOTE Adjust only the differential regulator at 25% (2.0V) control signal; do not adjust the air shutter. 14. Once the oxygen level is within the specified range at 25% (2.0V), change the firing rate to 10% (1.4V). 40

41 15. Oxygen levels at the 10% (1.4V) firing rate should be as shown in Table 5. Also, ensure that the CO and NOx readings do not exceed the values shown. No adjustment should be necessary. Contact the Factory if the oxygen, CO or NOx levels are not within the specified ranges. Table 5 Combustion Oxygen Levels for a 10% (1.4V) Firing Rate Inlet Air Temp Oxygen (± 0.2%) Carbon Monoxide *NOx 40 F <10% <100 ppm <20 ppm 50 F <10% <100 ppm <20 ppm 60 F <10% <100 ppm <20 ppm 75 F <10% <100 ppm <20 ppm 85 F <10% <100 ppm <20 ppm 90 F <10% <100 ppm <20 ppm 100 F <10% <100 ppm <20 ppm *Tabulated data are uncorrected ppm NOx values and will be less than or equal to 30 ppm of NOx when corrected to 3% oxygen. 16. Change the firing rate to 100%. After the combustion analyzer has settled, compare the measured oxygen level with the levels in Table 6. Table 6 Combustion Oxygen Levels for a 100% (5.0V) Firing Rate Inlet Air Temp Oxygen (±0.2%) Carbon Monoxide *NOx 40 F 8.8 % <100 ppm <20.3 ppm 50 F 8.1 % <100 ppm <21.4 ppm 60 F 7.5 % <100 ppm <22.5 ppm 75 F 6.5 % <100 ppm <24.1 ppm 85 F 5.8 % <100 ppm <25.3 ppm 90 F 5.3 % <100 ppm <26.1 ppm 100 F 4.8 % <100 ppm *Tabulated Data are uncorrected ppm NOx values and will be less than or equal to 30 ppm of NOx when corrected to 3% oxygen. 17. If the measured oxygen reading is below the oxygen range in Table 6, loosen the two bolts that secure the inlet air shutter to the unit using a 7/16 wrench (see Figure 4.4). Open the shutter 1/4 to 1/2 to increase the oxygen level, then tighten the nuts. 18. Wait for the analyzer to settle then compare the new oxygen reading to Table 6. Repeat the inlet air shutter adjustment until the oxygen is within the specified range. Also, ensure that the CO and NOx emissions do not exceed the values shown. Firmly tighten the inlet air shutter locking nuts when finished. 41

42 NOTE At 25% (2.0V) firing rate, adjust only the differential pressure regulator. At 100% (5.0V) firing rate, adjust only the inlet air shutter. 19. If the measured oxygen reading is above the oxygen range in Table 6, loosen the two 7/16" locking nuts securing the inlet air shutter. Close the air shutter 1/4 to 1/2 to decrease the oxygen level and tighten the two nuts. 20. Allow the analyzer to settle then compare the new oxygen reading to Table Repeat the adjustment until the oxygen is within the specified range. Also, ensure that the CO and NOx readings do not exceed the values shown. Firmly tighten the inlet air shutter locking nuts when finished. NOTE Adjust the inlet air shutter only at 100% (5.0V) firing rate. Do not adjust the differential pressure regulator. 22. Change the firing rate to 25% (2.0V). Allow time for the combustion analyzer to settle. Check the measured oxygen level, CO and NOx emissions to ensure that they are still within the ranges shown in Table Continue these procedures until all oxygen levels are within the ranges specified in Tables 4, 5 and Record all readings on the AERCO start-up sheet provided with each unit. Proceed to paragraph 4.4 when all natural gas combustion calibration procedures are completed. 5.5 Unit Reassembly Following Combustion Calibration Once combustion calibration is set properly, the unit can be reassembled for permanent operation. 1. Set the ON/OFF switch to the OFF position. Disconnect AC power from the unit. 2. Shut off the gas supply to the unit. 3. Remove any regulator adjustment tools by first pulling up the screwdriver blade to disengage it from the regulator adjusting screw, and then turning the tool out of the top of the regulator. 4. Apply a drop of silicone adhesive to the regulator adjusting screw to lock its setting. Remove the gasket from the tool and place it back onto the regulator cap. 5. Reinstall the cap and gasket back on the regulator. Tighten the cap using a screwdriver or wrench. 6. Remove all of the manometers and barbed fittings and reinstall the pipe plugs using a suitable thread compound. 7. Remove the combustion analyzer probe from the vent hole. Seal the probe hole and replace the vent connection cover. 8. Replace the unit s panels and hood. The KC1000 is now ready for Low NOx operation. 42