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O23/OHR23 OF23 Corp. 9535−L8 Revised 09/2003 Service Literature O23 / OHR23 / OF23 SERIES UNITS O23 (Elite 80) series units are mid−efficiency up-flow oil furnaces manufactured with Beckett oil burners. O23 units are available in heating capacities of 70,000 to 154,000 Btuh (20.5 to 45.1 kW) and cooling applications from 2 through 5 tons (7.0 through 17.6 kW). Refer to Engineering Handbook for proper sizing. OHR23 (Elite 80) series units are mid−efficiency horizontal / down-flow oil furnaces. The OF23 (Elite 80) series units are mid−efficiency lo-boy up-flow oil furnaces, which come in front (OF23) or rear (OF23R) flue openings, both with Beckett oil burners. The OHR23 and OF23(R) units are available in heating capacities of 105,000 to 154,000 Btuh (30.8 to 45.1 kW) and cooling applications from 2 through 5 tons (7.0 through 17.6 kW). Refer to Engineering Handbook for proper sizing. The drum type heat exchanger comes with strategically placed ports allowing easy cleaning, while the oil burner can be removed for inspection and service. The maintenance section gives a detailed description on how this is done. Information contained in this manual is intended for use by experienced HVAC service technicians only. All specifications are subject to change. Procedures outlined in this manual are presented as a recommendation only and do not supersede or replace local or state codes. O23 SHOWN TABLE OF CONTENTS WARNING General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Electric shock hazard. Can cause injury or death. Before attempting to perform any service or maintenance, turn the electrical power to unit OFF at disconnect switch(es). Unit may have multiple power supplies. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Indoor Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Parts Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 I Unit Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 II Placement and Installation . . . . . . . . . . . . . . . . . . . . 16 III Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 IV Heating Systems Service Checks . . . . . . . . . . . . . 22 WARNING V Disassembling Burner . . . . . . . . . . . . . . . . . . . . . . . . 24 Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a qualified installer or service agency. VI Typical Operating Characteristics . . . . . . . . . . . . . 26 VII Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 VIII Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . 28 IX Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Page 1 © 1995 Lennox Industries Inc. Litho U.S.A. SPECIFICATIONS − O23 Model Number O23Q2-70 O23Q3-105/120 O23Q5-140/154 InputBtuh (kW) low/high 70,000 (20.5) 105,000 / 120,000(30.8 / 35.2) 140,000 / 154,000(41.0 / 45.1) Output Btuh (kW) low/high 57,000 (16.7) 85,000 / 97,000 (24.9 / 28.4) 113,000 / 125,000 (33.1 / 36.6) *A.F.U.E. Nozzle Rating gph (L/hr) and spray angle 83.8% 82.8% (-105) / 82.5% (-120) 82.5% (-140) / 81.4% (-154) .50 (1.9) 80° hollow .65 (2.5) 80° (-105 input) solid .75 (2.8) 80° (-120 input) solid .85 (3.2) 80° (-140 input) solid 1.00 (3.8) 80° (-154 input) solid 6 (152) 6 (152) 6 (152) Flue Size Diameterin. (mm) Oil Burner Pump Oil Burner Pump Pressure psig (Pa) 1 Stage 1 Stage 1 Stage 100 (690) 140 (965) 140 (965) in. 10 x 6 10 x 8 12 x 9 mm 254 x 152 254 x 203 305 x 229 1/3 (249) 1/3 (249) 3/4 (560) Tons 2 thru 2.5 2 thru 3.5 3 thru 5 kW 7.0 thru 8.8 7.0 thru 12.3 10.6 thru 17.6 **Number and size of filtersin. (mm) (1) 16 x 25 x 1 (1) 16 x 25 x 1 (2) 16 x 25 x 1 Shipping weight lbs. (kg) 1 package 225 (102) 225 (102) 275 (125) Blower wheel nominal diameter x width Blower Motor Output hp (W) Nominal cooling that can be added Electrical characteristics 115 volts 60 hertz 1 phase Optional Accessories (Must Be Ordered Extra) Two Stage Oil Pump 65A44 Oil Filter 81P89 *Annual Fuel Utilization Efficiency based on U.S. DOE test procedures and FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces. **Cleanable frame type filters. Furnished with unit in Side Filter Adaptor Kit for field installation external to the cabinet. Requires return air from both sides of cabinet. Nozzle must be field provided for field conversion to higher heating input. SPECIFICATIONS − OHR23 Model Number InputBtuh (kW) low/high OutputBtuh (kW) low/high *A.F.U.E. (low/high) OHR23Q3-105/120 OHR23Q5-140/154 105,000 / 120,000(30.8 / 35.2) 140,000 / 154,000(41.0 / 45.1) 85,000 / 97,000 (24.9 / 28.4) 113,000 / 125,000 (33.1 / 36.6) 81.8% / 81.3% 81.5% / 81.7% Nozzle RatingU.S. gph (L/hr) and spray angle .65 (2.5) 80 (-105 input) solid .75 (2.8) 80 (-120 input) solid .85(3.2) 80(-140 input) solid 1.00 (3.8) 80 (-154 input) solid Flue Size Diameterin. (mm) 6 (152) 6 (152) Oil Burner Pump 1 Stage 1 Stage 140 (965) 140 (965) 10 x 10 (254 x 254) 12 x 9 (305 x 229) 1/2 (373) 3/4 (560) Tons 2 to 3 3 to 5 kW 7.0 to 10.6 10.6 to 17.6 225 (102) 265 (120) Oil Burner Pump Pressure psig (Pa) Blower wheel nominal diameter x width in. (mm) Blower motor outputhp (W) Nominal cooling that can be added Shipping weightlbs. (kg) 1 package Electrical characteristics 115 volts 60 hertz 1 phase Optional Accessories (Must Be Ordered Extra) Two Stage Oil Pump Filter Kit 65A44 Catalog no. No & size of filters in (mm) No. filtersin. 35K01 35K06 10 1/4 x 20-1/2 20 1/2 x 1 (260 x 521 x 25) (2) 10-1/4 11 3/4 x 23-1/2 23 1/2 x 1 (298 x 597 x 25) (2) 11-3/4 Down-flo Additive Base 35K07 Horizontal Venting Kit 35K08 62J01 Burner Cover 84H26 Vestibule Cover Kit (full front cover) 37K28 Oil Filter 37K29 81P89 *Annual Fuel Utilization Efficiency based on U.S. DOE test procedures and FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces. Nozzle must be field provided for field conversion to higher heating input. Page 2 SPECIFICATIONS − OF23 OF23Q3-105/120 OF23Q3-105/120R OF23Q5-140/154 OF23Q5-140/154R 105,000 / 120,000(30.8 / 35.2) 140,000 / 154,000(41.0 / 45.1) 85,000 / 97,000 (24.9 / 28.4) 113,000 / 125,000 (33.1 / 36.6) 82.4% / 81.5% 82.5% / 82.4% R Models 81.8% / 81.5% 82.0% / 81.8% R Models .65 (2.5) 80° (-105 input) .75 (2.8) 80° (-120 input) .85 (3.2) 80° (-140 input) 1.00 (3.8) 80° (-154 input) 6 (152) 6 (152) Model Number InputBtuh (kW) low/high OutputBtuh (kW) low/high *A.F.U.E. (low/high) Nozzle Ratinggph (L/hr) and spray angle Flue Size Diameterin. (mm) Oil Burner Pump Oil Burner Pump Pressure psig (Pa) 1 Stage 1 Stage 140 (965) 140 (965) Optional 2 Stage Fuel Pump 65A44 in. Blower wheel nominal diameter x width 10 x 8 12 x 9 254 x 203 305 x 229 1/3 (249) 3/4 (560) 2 thru 3 (7.0 thru 10.6) 3 thru 5 (10.6 thru 17.6) mm Blower Motor Outputhp (W) Nominal cooling that can be addedTons (kW) in. Number and size of filters mm (1) 18 x 19 x 1 (1) 19 x 21 x 1 (1) 457 x 483 x 25 (1) 483 x 533 x 25 255 (116) 290 (132) Shipping weightlbs. (kg) 1 package Electrical Characteristics 115 60 hertz 1 phase Optional Accessories (Must Be Ordered Extra) Two Stage Oil Pump 65A44 Oil Filter 91P89 *Annual Fuel Utilization Efficiency based on U.S. DOE test procedures and FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces. Nozzle must be field provided for field conversion to higher heating input. BLOWER PERFORMANCE DATA − O23 O23Q2-70 BLOWER PERFORMANCE External Static Pressure O23Q3-105/120 BLOWER PERFORMANCE Air Volume at Various Blower Speeds High Medium Air Volume at Various Blower Speeds External Static Pressure Low High Medium Low in.w.g. Pa cfm L/s cfm L/s cfm L/s in. w.g. Pa cfm L/s cfm L/s cfm L/s .20 50 1260 595 870 410 520 245 .20. 50 1350 635 1215 575 1080 510 .30 75 1205 570 825 390 500 235 .30 75 1280 605 1180 555 1060 500 .40 100 1135 535 780 370 480 225 .40 100 1210 570 1140 540 1040 490 .50 125 1050 495 720 340 450 210 .50 125 1180 444 1085 510 1000 470 .60 150 960 455 660 310 410 195 .60 150 1100 520 1025 485 950 450 NOTE All air data is measured external to the unit with the air filter in place. NOTE All air data is measured external to the unit with the air filter in place. O23Q5-140/154 BLOWER PERFORMANCE External Static Pressure Air Volume at Various Blower Speeds High Medium Low in. w.g. Pa cfm L/s cfm L/s cfm L/s .20 50 1950 920 1620 765 1250 590 .30 75 1900 895 1590 750 1230 580 .40 100 1880 885 1560 735 1210 570 .50 125 1850 875 1540 725 1190 560 .60 150 1800 850 1490 705 1155 545 NOTE All air data is measured external to the unit with the air filter in place. Page 3 BLOWER PERFORMANCE DATA − OHR23 OHR23Q3-105/120 BLOWER PERFORMANCE External Static Pressure OHR23Q5-140/154 BLOWER PERFORMANCE Air Volume at Various Speeds High Medium Air Volume at Various Speeds External Static Pressure Low High Medium Low in w.g. Pa cfm L/s cfm L/s cfm L/s in w.g. Pa cfm L/s cfm L/s cfm L/s .20 50 1470 695 1360 640 1070 505 .20 50 1950 920 1700 800 1340 630 .30 75 1400 660 1300 615 1040 490 .30 75 1920 905 1650 780 1300 615 .40 100 1330 630 1230 580 1020 480 .40 100 1900 895 1600 755 1270 600 .50 125 1260 595 1160 545 980 460 .50 125 1870 880 1580 745 1220 575 .60 150 1180 555 1085 510 920 435 .60 150 1780 840 1500 710 1170 550 NOTE All air data is measured external to the unit with air filter in place. NOTE All air data is measured external to the unit with air filter in place. BLOWER PERFORMANCE DATA − OF23 FRONT FLUE MODELS OF23Q3-105/120 BLOWER PERFORMANCE External Static Pressure OF23Q5-140/154 BLOWER PERFORMANCE Air Volume at Various Blower Speeds High Medium External Static Pressure Low in. w.g. Pa cfm L/s cfm L/s cfm L/s in. w.g. Pa .20 50 1490 705 1370 645 1190 560 .20 .30 75 1430 675 1345 635 1180 555 .30 .40 100 1375 650 1280 605 1160 545 .50 125 1300 615 1230 580 1120 530 .60 150 1230 580 1160 545 1080 510 NOTE All air data is measured external to the unit with the air filter in place. Air Volume at Various Blower Speeds High Medium Low cfm L/s cfm L/s cfm L/s 50 2110 995 1850 875 1500 710 75 2035 960 1810 855 1480 700 .40 100 1970 930 1750 825 1450 685 .50 125 1950 920 1690 800 1420 670 .60 150 1880 885 1620 765 1375 650 NOTE All air data is measured external to the unit with the air filter in place. REAR FLUE MODELS OF23Q3-105/120R BLOWER PERFORMANCE External Static Pressure OF23Q5-140/154R BLOWER PERFORMANCE Air Volume at Various Blower Speeds High Medium External Static Pressure Low Air Volume at Various Blower Speeds High Medium Low in. w.g. Pa cfm L/s cfm L/s cfm L/s in. w.g. Pa cfm L/s cfm L/s cfm L/s .20 50 1470 695 1330 630 1150 545 .20 50 2010 950 1765 835 1380 650 .30 75 1410 665 1295 610 1140 540 .30 75 1960 925 1720 810 1350 635 .40 100 1340 630 1250 590 1125 530 .40 100 1900 895 1660 785 1330 630 .50 125 1280 605 1190 560 1080 510 .50 125 1880 885 1600 755 1295 610 .60 150 1205 670 1130 535 1030 485 .60 150 1800 850 1560 735 1230 580 NOTE All air data is measured external to the unit with the air filter in place. NOTE All air data is measured external to the unit with the air filter in place. Page 4 O23 GENERAL PARTS ORIENTATION HEAT EXCHANGER VENT OPENING CLEAN-OUT PORT LIMIT SWITCH CLEAN-OUT PORT CONTROL BOX WITH FAN CONTROL OBSERVATION PORT BECKETT AFII BURNER COMBUSTION AIR INTAKE BLOWER MOTOR INDOOR BLOWER CAPACITOR FIGURE 1 OHR23 GENERAL PARTS ORIENTATION CLEAN-OUT PORT HEAT EXCHANGER LIMIT SWITCH BLOWER MOTOR BECKETT AFII BURNER COMBUSTION AIR INTAKE OBSERVATION PORT CLEAN-OUT PORT VENT OPENING CONTROL BOX WITH FAN CONTROL FIGURE 2 Page 5 INDOOR BLOWER OF23 GENERAL PARTS ORIENTATION FILTER FRONT VENT OPENING (OF23) INDOOR BLOWER CLEAN-OUT PORT LIMIT SWITCH REAR VENT OPENING (OF23R) CONTROL BOX WITH FAN CONTROL HEAT EXCHANGER BECKETT AFII BURNER CLEAN-OUT PORT COMBUSTION AIR INTAKE OBSERVATION PORT FIGURE 3 BCC2 / BCC3 BLOWER CONTROL BOARD 120VAC LINE VOLTAGE IN 120VAC CONTINUOUS FAN COOLING TRANSFORMER TERMINAL COMMON SPEED TAP HEATING SPEED TERMINAL TAP TERMINAL NEUTRAL TERMINALS ACCESSORY TERMINAL 24VAC OUTPUT TO BURNER (HEAT DEMAND) BLOWER TIME ADJUSTMENT JUMPER 24VAC IN FROM PRIMARY LIMIT 24VAC THERMOSTAT DEMAND OUTPUT To Remove Terminal Strip, Grasp Ends of Block Between Thumb and Forefinger. Push Block Down and Out. (Jack / Plug 94) 24VAC INPUT 24VAC COMMON THERMOSTAT TERMINAL STRIP TB1 (DETACHABLE ON EARLY −1 AND −2 FROM TRANSFORMER FROM TRANSFORMER MODELS ONLY) FIGURE 4 Page 6 I−UNIT COMPONENTS General parts orientation for the O23, OHR23 and OF23 are shown in figures 1, 2 and 3 respectively. The O23 and OF23 control box, burner, limit switch and clean-out ports may be accessed by removing the front access panel, while the OHR23 components are exposed. The blower can be accessed in the O23 and OF23 by removing the blower access panel, while in the OHR23 units two 1/4" screws must be removed before the blower access panel can be removed. Figure 5 shows the various fan off" timings and how jumper should be positioned. Unit is shipped with a factory fan off" setting of 150 seconds. Fan off" time will affect comfort and efficiency and is adjustable to satisfy individual applications. The fan off" timing is initiated after a heating demand but not after a blower or cooling demand (that is, when indoor thermostat switch is changed from ON to AUTO and heating/cooling demand is not present, the blower stops immediately). FAN-OFF TIME ADJUSTMENT ELECTROSTATIC DISCHARGE (ESD) Precautions and Procedures To adjust fan−off timings: Remove jumper from BCC2 and select one of the other pin combinations to achieve the desired time. TIMING JUMPER CAUTION 270 Electrostatic discharge can affect electronic components. Take precautions during unit installation and service to protect the unit’s electronic controls. Precautions will help to avoid control exposure to electrostatic discharge by putting the unit, the control and the technician at the same electrostatic potential. Neutralize electrostatic charge by touching hand and all tools on an unpainted unit surface before performing any service procedure. 210 Leave jumper off to achieve 330 second fan−off timing. TIMING PINS (seconds) 150 Fan-off timing is factory set at 150 seconds 90 FIGURE 5 Thermostat Connection Thermostat wires are connected to terminal strip TB1 found on the BCC2 control board. The terminal strip is clearly marked with the corresponding thermostat designation. The terminal strip (jack / plug 94) is simply removed by grasping the ends of the block and rotating down while pulling away (see figure 4). A−Blower Control Board BCC2 Blower Control Board (Figure 4) −1 and −2 units TABLE 1 All O23, OHR23 and OF23−1 and −2 oil units utilize the BCC2 (A15) blower control manufactured by Heatcraft. The BCC2 is a printed circuit board which controls the supply air blower and monitors the limit controls and oil burner operation. The control has a non-adjustable, factory preset fan-on" timing. Fan off" timing is adjustable. The board is divided into two sections, 120 and 24VAC. Line voltage comes into the board on the 120VAC side. See figure 4. See table 1 for BCC2 terminal designations. BLOWER CONTROL A15 TERMINAL DESIGNATIONS Terminal Type Function W Heating Demand NEUTRAL L1 Detachable Screw Strip Detachable Screw Strip Detachable Screw Strip Detachable Screw Strip Detachable Screw Strip 1/4" Spade 1/4" Spade A 1/4" Spade XFMRN 1/4" Spade CF 1/4" Spade H 1/4" Spade ACC 1/4" Spade VALVE SENSE 3/16" Spade LIMIT 1/4" Spade WI 1/4" Spade 24V 1/4" Spade COM 1/4" Spade R Y C G DANGER Shock hazard. Avoid personal injury. Make sure to disconnect power before changing fan off" timing. Blower Operation and Timing Blower off" timing (time that the blower operates after the heat demand has been satisfied) is determined by the arrangement of a jumper across pins on the BCC2 blower control board. See figure 4. To adjust fan off " timing, gently disconnect jumper and reposition across pins corresponding with new timing. Fan on" time is factory set at 45 seconds and is not adjustable. NOTEIf fan off" time is set too low, residual heat in heat exchanger may cause primary limit S10 or auxilary limit S21 to trip resulting in frequent cycling of blower. If this occurs, adjust blower to longer time setting. Page 7 24VAC to Thermostat Cooling Demand 24VAC Common To Indoor Thermostat Blower Demand 120VAC Neutral 120VAC Line Voltage In Switched 120VAC to Blower Cooling Tap 120VAC Transformer Common Switched 120VAC to Continuous Blower Tap Switched 120VAC to Blower Heating Tap Switched 120VAC to Accessory (Electronic Air Cleaner, Humidifier, Etc. 1 amp rating.) 24VAC Output To Burner 24VAC In From Primary Limit. Limit Open: Stops Burner and Turns On Blower Limit Closed: Allows Burner Operation 24VAC Thermostat Demand Output 24VAC Input From Transformer 24VAC Common From Transformer Thermostat Connection BCC3 Blower Control Board (Figure 4) −3 and −4 units All O23, OHR23 and OF23−3 and −4 oil units utilize the BCC3 (A15) blower control manufactured by Heatcraft. The BCC3 is a printed circuit board which controls the supply air blower and monitors the limit controls and oil burner operation. The control has a non-adjustable, factory preset fan-on" timing. Fan off" timing is adjustable. The board is divided into two sections, 120 and 24VAC. Line voltage comes into the board on the 120VAC side. See figure 4. See table 2 for BCC3 terminal designations. Thermostat wires are connected to terminal strip TB1 found on the BCC3 control board. The terminal strip is clearly marked with the corresponding thermostat designation. The terminal strip (jack / plug 94) is simply removed by grasping the ends of the block and rotating down while pulling away (see figure 4). DANGER Shock hazard. Avoid personal injury. Make sure to disconnect power before changing fan off" timing. Blower Operation and Timing Blower off" timing (time that the blower operates after the heat demand has been satisfied) is determined by the arrangement of a jumper across pins on the BCC3 blower control board. See figure 4. To adjust fan off " timing, gently disconnect jumper and reposition across pins corresponding with new timing. Fan on" time is factory set at 45 seconds and is not adjustable. NOTEIf fan off" time is set too low, residual heat in heat exchanger may cause primary limit S10 or auxilary limit S21 to trip resulting in frequent cycling of blower. If this occurs, adjust blower to longer time setting. Figure 5 shows the various fan off" timings and how jumper should be positioned. Unit is shipped with a factory fan off" setting of 150 seconds. Fan off" time will affect comfort and efficiency and is adjustable to satisfy individual applications. The fan off" timing is initiated after a heating demand but not after a blower or cooling demand (that is, when indoor thermostat switch is changed from ON to AUTO and heating/cooling demand is not present, the blower stops immediately). TABLE 2 BLOWER CONTROL A15 TERMINAL DESIGNATIONS Terminal Type Function W Detachable Screw Strip Heating Demand R Detachable Screw Strip 24VAC to Thermostat Y Detachable Screw Strip Cooling Demand C Detachable Screw Strip 24VAC Common To Indoor Thermostat G Detachable Screw Strip Blower Demand NEUTRAL 1/4" Spade 120VAC Neutral L1 1/4" Spade A 1/4" Spade 120VAC Line Voltage In Switched 120VAC to Blower Cooling Tap XFMRN 1/4" Spade 120VAC Transformer Common CF 1/4" Spade Switched 120VAC to Continuous Blower Tap H 1/4" Spade Switched 120VAC to Blower Heating Tap ACC 1/4" Spade Switched 120VAC to Accessory (Electronic Air Cleaner, Humidifier, Etc. 4 amp rating.) VALVE SENSE 3/16" Spade 24VAC Output To Burner LIMIT 1/4" Spade 24VAC In From Primary Limit. Limit Open: Stops Burner and Turns On Blower Limit Closed: Allows Burner Operation WI 1/4" Spade 24VAC Thermostat Demand Output 24V 1/4" Spade 24VAC Input From Transformer COM 1/4" Spade 24VAC Common From Transformer FAN-OFF TIME ADJUSTMENT TIMING JUMPER 270 To adjust fan−off timings: Remove jumper from BCC2 and select one of the other pin combinations to achieve the desired time. 210 Leave jumper off to achieve 330 second fan−off timing. TIMING PINS (seconds) 150 90 Fan-off timing is factory set at 150 seconds FIGURE 6 Page 8 ST9103A Blower Control Board (Figure 8) −5 units ST9103A Blower Control Board 120V All O23, OHR23 and OF23 −5 oil units utilize the ST9103A (A15) blower control manufactured by Honeywell. The ST9103A is a printed circuit board which controls the supply air blower and monitors the limit controls and oil burner operation. The control has a non-adjustable, factory preset fan-on" timing. Fan off" timing is adjustable. See figure 8 andtable 3 for ST9103A terminal designations DANGER fan off delay switches Shock hazard. Avoid personal injury. Make sure to disconnect power before changing fan off" timing. thermostat terminal strip Blower Operation and Timing The fan on time of 30 seconds is not adjustable. Fan off time (time that the blower operates after the heat demand has been satisfied) can be adjusted by moving the delay switches on the fan control board. Fan off time will affect comfort and is adjustable to satisfy individual applications. See figure 7. Set the heat fan off delay switches to either 60, 90, 120, or 150 seconds. The factory setting is 90 seconds. NOTEIf fan off" time is set too low, residual heat in heat exchanger may cause primary limit S10 or auilary limit S21 to trip resulting in frequent cycling of blower. If this occurs, adjust blower to longer time setting. Thermostat Connection Thermostat wires are connected directly to the terminlas on the ST9103A board. See figure 8. Continuous Blower If the ST9103A blower control board is wired for continuous blower, the blower will energized on low speed and remain energized when heat or cool demand is satisfied. Continuous blower will also energized when indoor thermostat is left in the OFF mode. Fan Off Delay Switch Settings ON ON 60 sec ON 90 sec ON 120 sec 150 sec Figure 7 Page 9 Figure 8 TABLE 3 BLOWER CONTROL A15 TERMINAL DESIGNATIONS J58 Pin # 1 2 3 4 5 6 7 Function Limit S10 L1 120V T1 24V L2 Common Jumpered to Pin 4 T2 24V Combustion Air Inducer 120V 8 Jumpered to Pin 7 9 Limit S21 (if used) Thermostat Connections G Blower Demand W Heating Demand R 24V Y Cooling Demand C Common 24 VAC CONNECTIONS X 24V Transformer C Common Transformer 120 VAC S2 Line S3 120V To Transformer N, 2, 3, 4, 6, 7 Neutral CONT Continuous Blower COOL Cool Tap HEAT Heat Tap −1THROUGH −4 UNIT OIL BURNER PARTS ARRANGEMENT AIR TUBE SCREWS FLANGE GASKET FLANGE HOLE PLUG AIR TUBE ASSY FOR FB HEADS RETAINING CLIP ELECTRONIC IGNITION TRANSFORMER MAIN HOUSING ASSY ESCUTCHEON PLATE CONNECTOR TUBE FB-HEAD HEAD INSULATOR NOZZLE ADAPTER NOZZLE LINE ELECTRODE HEAD ASSY. ELECTRODE ASSY BURNER CONTROL ELECTRONIC IGNITION TRANSFORMER RESET BUTTON REAR ACCESS DOOR GASKET VIEW PORT REAR ACCESS DOOR ASSY 0 SPLINED NUT AIR ADJUSTMENT DIAL 3 4 5 6 7 8 OIL PUMP COUPLING COMBUSTION AIR MOTOR BLOWER WHEEL FIGURE 9 Page 10 INLET AIR SCOOP −5 UNIT BURNER PARTS ARRANGEMENT FLANGE GASKET ELECTRONIC IGNITION TRANSFORMER AIR TUBE SCREWS FLANGE AIR TUBE ASSY FOR FB HEADS RETAINING CLIP 1/4" HEX HEAD SCREW MAIN HOUSING ASSY ESCUTCHEON PLATE CONNECTOR TUBE FB−HEAD HEAD INSULATOR NOZZLE ADAPTER NOZZLE LINE ELECTRODE HEAD ASSY. ELECTRODE ASSY PEDESTAL PREMOUNTED PRE−PURGE VALVE IGNITOR PRIMARY CONTROL 4X4 BOX REAR ACCESS DOOR GASKET REAR ACCESS DOOR ASSY SPLINED NUT 0 3 4 5 6 7 8 AIR ADJ. DIAL FUEL PUMP COUPLING BLOWER WHEEL MOTOR FIGURE 10 Page 11 INLET AIR SCOOP TABLE 4 FURNACE / BURNER SPECIFICATIONS Unit Lennox Burner Part Number Burner Model *Initial Air Dial Setting Output Nozzle Size (Delevan) Pump Pressure Head -70 35K74 AFII 85 3.0 57,000 BTU (16.7 kW) 0.50 X 80A 100 psig (689.5 kPa) FB0 -105 35K75 AFII 85 4.0 84,000 BTU (24.6 kW) 0.65 X 80B 140 psig 965.3 kPa) FB3 -120 35K75 AFII 85 4.5 105,000 BTU (30.8 kW) 0.75 X 80B 140 psig 965.3 kPa) FB3 -140 35K76 AFII 150 6.0 -154 35K76 AFII 150 6.5 112,000 BTU (32.8 kW) 125,000 BTU (36.6 kW) 0.85 X 80B 1.00 X 80B 140 psig 965.3 kPa) 140 psig 965.3 kPa) FB6 FB6 *NOTE: The initial air dial setting is provided to get unit started. The air dial setting MUST be adjusted after start-up to achieve proper combustion. B−Burner (Figures 9 & 10) 3− Pump (−1 through −4 units) The O23, OHR23, and OF23 oil furnaces use the Beckett AFII burner. The oil burner provides an atomized oil vapor mixed with the correct proportion of air when it is ignited in the combustion chamber. Oil burner minimum and maximum ratings are listed on the unit nameplate. Proper air adjustment for these ratings is achieved through the air adjustment dial. Set air dial to the initial air dial setting (see table 4). After start up adjust air dial to achieve proper combustion. Remember to tighten set screw on air dial. The AFII burner is available in five sizes with either a single or two stage pump. Table 4 identifies the burners used in Lennox units. Figures 9 and 10 show the typical layout of the burner assembly. The O23, OHR23, and OF23 oil furnaces use a single stage, 3450 RPM pump. A two stage pump is available as an option (catalog # 65A44). The oil burner is shipped from factory for use in a single line system. To convert the pump to a two line system, install the bypass plug provided in the attached bag according to the accompanying instructions. 1−Combustion Air Blower / Pump Motor (B6) The burner is activated by the primary control. A combustion air blower is mounted on the motor shaft. The motor shaft also connects to the direct drive oil pump through a coupler. The burner motor turns both the combustion air blower and the oil pump. The motor operates at 3500 RPM. Burner motors are overload protected. In the event of excess motor temperature or current, the overload opens to de−energize the motor. The overload automatically resets after temperature has returned to normal. Keep motor clean to prevent starting switch from sticking. All AFII motors are permanently lubricated. No further oiling is required. 2−Combustion Air Blower / Pump Fuse (F22) (−140 and −154 CSA units only) In the −140 and −154 Canadian units an in line fuse (F22) is used between the line voltage from the BCC2 blower control and the blower / pump motor. The fuse is rated at 300 volts and 15 amps. 4− Pump (−5 units only) The O23, OHR23 and OF23−5 units all utilize the Cleancut Fuel Unit manufactured by Becket. This pump uses a solenoid valve to control the piston cut−on cut−off operation instead of a cone valve and diaphram used by other conventional pumps. The solenoid works with the R7184B Honeywell burner control to provide cut−on cut−off operation while the burner motor is at full speed. At startup the pump shaft is brought to full speed before the solenoid is energized. At this time low pressure oil (approximatley 20−25 psi) from the gearset circulates around the pressure regulator piston which is closed and through the open solenoid valve. The solenoid valve returns the oil to either the cover cavity (one pipe) or return line (two pipe). When the solenoid vavle is energized, it closes (and remains closed while energized) blocking the return path to the cover cavity and return line creating pressure build up in the piston cavity. The piston opens and regulates pressure and delivers pressurized oil to the nozzle. At shutdown the solenoid valve will de−energize and open before the pump shaft rotation stops. When the solenoid valve opens the oil by−passes the cover cavity and return line causing a pressure drop in the piston cavity. The piston closes blocking oil to the nozzle while the burner motor is running at full speed. Page 12 TABLE 5 5−Burner Control (A3) & Transformer (T1) −1 through −4 units The burner control, along with the matching cad cell, proves flame and controls the burner. After the cad cell closes a circuit to the burner control, the burner control de−energizes the safety switch heater to allow the unit to operate normally. The burner control allows 45 seconds for the cad cell to close. If the cad cell remains open after the 45 second time frame, the burner control locks out. The burner control must be manually reset by depressing the red reset button on top of the burner control. Transformer (T1) is part of the burner control. T1 provides 24VAC to the low voltage components in the unit and to the thermostat. 6−Burner Control (A3) −5 units All O 23, OHR23 and OF23 −5 units are equipped with a burner control R7184B manufactured by Honeywell. The burner control, along with the matching cad cell, proves flame and controls the burner. An LED on the control shows unit status. See table 5 for status codes. After the cad cell closes a circuit to the burner control, the burner control de−energizes the safety switch heater to allow the unit to operate normally. When there is a call for heat the control performs a 2 to 6 second delay safety check. Once this is established a 15 second pre− puge will follow. The valve then opens for a 15 second trial for ignition. If flame is not sensed during the 15 second trial, the control shuts down and must be manual re−set. After three consecutive lockouts the control goes into restricted lockout. Once flame is established after 10 seconds of run time, the igniiton shuts off. If flame is lost during the heat cycle the control will shut down the burner and begin a 60 second recycle delay. After 60 seconds the control repeats the ignition process. If flame is lost three consecutive times during a single thermostat demand the control goas into restricted lockout. LED STATUS On Flame sensed Off Flame not sensed Flashing (1/2 sec on1/2 sec off) Lockout / Restricted Lockout Flashing (2 sec on 2 sec off) Recycle 7−Heat Shutoff Relay (K125) −1 and −2 units only Heat shutoff relay K125 is a SPST N.O. relay, with a 24V coil. K125 is located on the vestibule and wired in series with the burner. When secondary limit S21 or primary limit S10 open, the circuit breaks opening K125 contacts which in turn de−energizes the burner. 8−Cad Cell (R26) Together the cad cell and the burner control prove flame. The cad cell senses the presence of burner light (less resistance) to close a circuit to the burner control. IMPORTANT−Burner should not be installed so it is exposed to direct sunlight or electric bulb light. If the cell is exposed to light on start up, the burner will not operate. O23, OHR23 & OF23 −5 Units Only Resistance for the cad cell can be checked while the burner is firing and after ignition is off. Press (1/2 second or less) and release the reset button. The LED will flash 1 to 4 times depending on the cad cell resistance. The cad cell resistance should read less than 1600 Ohms. See table 6. Reset button If the control lockouts three consecutive times the control will go into restricted lockout. To reset control hold down the reset button for 30 seconds until the LED flashes twice. At any time the burner motor is energized, press and hold the reset button to disable the buner. The burner will remain disabled as long as the reset button is held and return to operational once the button is released. Page 13 TABLE 6 O23, OHR23 & OF23 −5 UNITS LED FLASHES RESISTANCE 1 0 − 400Ohms 2 400 − 800 Ohms 3 800 − 1600 Ohms 4 1600 Ohms 9−Electronic Ignitor (A73) 10−Gun Assembly The electronic ignitor provides the needed hot spark at the electrodes to ignite the fuel mixture. The ignitor is a solid state transformer . O23, OHR23 and OF23−1 through −4 units have 115V primary and 14,000V secondary windings. O23, OHR23 and OF23−5 units have 120V primary and 20,000V secondary windings. The center of the secondary winding is grounded. Each secondary terminal is 7000V to ground and the total voltage between the electrodes is 14,000V. The gun assembly receives oil from the oil pump and feeds it to the nozzle. The nozzle converts liquid oil into a fog−like mist that is discharged through the flame retention head into the combustion chamber. NOTE−The leads for the solid state transformer are replaceable and are available in a kit form. NOTE−When testing the solid state transformer, do not use a transformer tester designed for iron magnet transformers. Damage to the tester may result. 11−Flame Retention Heads The stainless steel flame retention head (see figure 11) is used to swirl (cone) the fog-like oil and air mixture as it enters the combustion chamber. Three different heads are used in the O23/OHR23/OF23. The firing rate dictates which head is used. See table 4. The greater the FB number the larger the slots on the head. When combustion takes place, the flame will be cylindrical compact shaped as a result. FLAME RETENTION HEAD FB3 SHOWN Testing the Ignitor WARNING SHOCK HAZARD Do not touch ignitor or any metal touching ignitor when ignitor is energized. Can result in serious personal injury. If the ignitor fails it will not produce a spark. Looking and listening for the arc is a simple way to check. The most sure way is to perform the screwdriver check. By placing the blade of an insulated screwdrivere across the ignitor terminal leads will test for an arc. First, remove power from the burner and disconnect the oil supply from nozzle. The cad cell will not let the control energize the ignitor if the cad cell senses light. Therefore remove one lead of the cad cell from the burner control, or remove the cad cell all together (do not forget to put back when test is complete). Place the screwdriver blade across the terminals and slowly raise one end of the blade off the terminal while the other remains in contact with the other terminal. There should be an arc from terminal to the blade up to 3/4" away. If not replace the ignitor. If an arc is present then place one end of the screwdriver on one terminal and the other end with the grounded baseplate. Raise the blade from the baseplate and draw an arc. Repeat with the other terminal. If the arc from the baseplate to one terminal is weaker than the arc from the baseplate to the other terminal, replace the ignitor. FIGURE 11 C−Primary Limit Control (S10) The primary limit on all O23, OHR23, and OF23 units, is located on the vestibule panel (see figures 1 through 3 for location and figure 12 for type). When excess heat is sensed in the heat exchanger, the limit will open. If the limit is tripped, the blower control de-energizes the thermostat, in turn shutting down the unit. The limit automatically resets when unit temperature returns to normal. The switch is factory set and cannot be adjusted. The switch has a different setpoint for each unit model number (see table 7). The setpoint is printed on the face plate of the limit. Page 14 TABLE 7 1.Blower Motor (B3) and Capacitor (C4) PRIMARY LIMIT CONTROL (S10) UNIT ACTUATES ON TEMP. RISE ACTUATES ON TEMP. FALL O23Q2−70 210F (99C) 180F (82C) O23Q3−105/120 220F (104C) 190F (88C) O23Q5−140/154 210F (99C) 180F (82C) OHR23Q3−105/120 240F (116C) 210F (99C) OHR23Q5−140/154 190F (88C) 160F (71C) OF23Q3−105/120 OF23Q3−105/120R 240F (116C) 210F (99C) OF23Q5−140/154 OF23Q5−140/154R 210F (99C) 180F (82C) All O23, OHR23, and OF23 series units use single phase direct drive blower motors. All motors used are 115V permanent split capacitor motors to ensure maximum efficiency. See SPECIFICATIONS tables for horsepower and motor nameplate for capacitor rating.The blower motor is connected to the blower control board via the blower motor plug P43. 2.Secondary Limit Control (S21) LIMIT CONTROL (S10) LIMIT SPADE CONNECTORS The secondary limit (S21) is used on the OHR23 series unit only. The N.C. limit is mounted on the side and toward the back of the blower housing. See figure 13 for location and figure 14 for type. When excess heat is sensed in the blower compartment, the limit will open. If the limit is tripped, the blower control de-energizes the thermostat, inturn shutting down the unit. The limit automatically resets when unit temperature returns to normal. The switch opens at 150F + 5F (65.5C + 2.8C) on a temperature rise and resets at 140F + 5F (60.0C + 2.8C) on a temperature fall. The switch is factory set and cannot be adjusted. The setpoint is printed on the face plate of the limit. INSULATING COVER FIGURE 12 SECONDARY LIMIT CONTROL (S21) D−Blower Compartment (Figure 13) Blower motor (B3), capacitor (C4), and secondary limit control (S21) are located in the blower compartment. The blower compartment can be accessed by removing the blower access panel. BLOWER COMPARTMENT (OHR23 SIDE VIEW SHOWN) SECONDARY LIMIT CONTROL (S21) (OHR23 ONLY) (BACK SIDE) FIGURE 14 E−Optional Accessories Optional accessories are available from Lennox for the O23, OHR23, and OF23 series units. Some accessories are in kit form which come with instructions. 1.Low Speed On − Off Switch (S68) BLOWER MOTOR CAPACITOR (C4) The low speed on - off switch is a kit (catalog # 67H91) which permits continuous low speed blower operation. The switch is a DPDT toggle switch. 2.Economizer Relay (K43) BLOWER MOTOR (B3) FIGURE 13 The economizer relay (catalog # 65G40) is used to energize the economizer if used. The relay is a 120V coil, single pole contact which is energized by the accessory terminal of the blower control board. Page 15 II−PLACEMENT AND INSTALLATION Air Vent Fill Pipe OIL PIPING ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ Make sure unit is installed in accordance with installation instructions and applicable codes. ONE-PIPE SYSTEM Fuel Unit A−Piping The piping system and it’s components (oil filter, safety valves, shut-off valves, etc.) must be designed to provide clean, air free fuel to the burner. Oil Tank An oil filter is required for all models. Use an oil filter of generous capacity for all installations. Install filter inside the building between the tank shut−off valve and the burner. Locate filter close to burner for easy servicing. The GAR−Ber 11BV−R or equivalent filter (with the below specifications) is recommended. Maximum Firing Rate: 10GPH (38LPH) Aux Filter 8 ft (2.4 m) Maximum One Pipe Lift Shut−off Valve FIGURE 15 Micron Removal: 10 OIL PIPING Filtering Area: 500 in.2 (3225.8 cm2) TWO-PIPE SYSTEM Fill Pipe Working Pressure: 15 PSI (103.4 kPa) Inlet/Outlet Dimension: 3/8" (9.5 mm) NPT Air Vent Fuel Unit ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Return Line Flow Rate: 45GPH (171LPH) Care must be taken to ensure the restriction of the piping system, plus any lift involved, does not exceed the capability of the oil pump. Each installation will be different. Use the following guide lines when determining to use a single or two stage pump. Aux Filter When using a single pipe system with the fuel supply level with or above the burner (see figure 15) and a vacuum of 6" (152 mm) Hg or below, a single stage fuel unit with a supply line and no return line should be adequate. Manual bleeding of the fuel unit is required on initial start up. Failure to bleed air from the pump could result in an air lock/oil starvation condition. NOTE−As an extra precaution, cycle heating on and off ten times after bleeding air from the pump. This will eliminate air in the gun assembly. When using a two pipe system with the fuel supply level below the level of the burner (see figure 16) a single stage fuel unit should be used in lift conditions of up to 10 feet (3 m) and/or a vacuum of 10" (254 mm) Hg or below. A two stage fuel unit should be used when lift exceeds 10 feet (3 m) and/or a vacuum of 10" (254 mm) Hg to 15" (381 mm) Hg. Both conditions require the use of a return line that purges the fuel unit of air by returning it to the fuel tank. Use table 8 when determining the run and lift for piping. Before converting a one-pipe system to a two-pipe system the pump must be converted to a two-pipe system. To convert the pump, install the bypass plug according to the instructions. Notice in the two-pipe system the return line must terminate 3" (76 mm) to 4" (102 mm) above the supply inlet. Failure to do this may introduce air into the system and could result in loss of prime. NOTE−If using an outside tank in cold climates a number one fuel or an oil treatment is strongly recommended. Page 16 Oil Tank Inlet H 3"−4" (76mm −102mm) R Return Line OUTSIDE TANK FUEL UNIT ABOVE BOTTOM OF TANK. FIGURE 16 TABLE 8 TWO−PIPE MAXIMUM LINE LENGTH (H + R) Lift H" Figure 15 g 0’ (0.0 m) 2’ (0.6 m) 4’ (1.2m) 6’ (1.8m) 8’ (2.4m) 10’ (3.0m) 12’ (3.7m) 14’ (4.3m) 16’ (4.9m) 18’ (5.5m) 3450 RPM − 3 GPH (11.4 LPH) 3/8" (10 mm) OD 1/2" (12 mm) OD Tubing Tubing Single Two Single Two Stage Stage Stage Stage 84’ (25.6 m) 73’ (22.3 m) 63’ (19.2 m) 52’ (15.8 m) 42’ (12.8 m) 31’ (9.4 m) 21’ (6.4 m) −−− −−− −−− 93’ (28.3 m) 85’ (25.9 m) 77’ (23.5 m) 69’ (21.0 m) 60’ (18.3 m) 52’ (15.9 m) 44’ (13.4 m) 36’ (11.0 m) 27’ (8.2 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 83’ (25.3 m) 41’ (12.5 m) −−− −−− −−− 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 100’ (30.5 m) 76’ (23.2 m) 2− The vent connector should be as short as possible to do the job. B−Venting Considerations WARNING 3− The vent connector should not be smaller than the outlet diameter of the vent outlet of the furnace. Combustion air openings in front of the furnace must be kept free of obstructions. Any obstruction will cause improper burner operation and may result in a fire hazard or injury. 4− Pipe should be at least 24 gauge galvanized. 5− Single wall vent pipe should not run outside or through any unconditioned space. 6− Chimney should extend 3 feet (0.9 m) above the highest point where the vent passes through the roof, and 2 feet (0.6 m) higher than any portion of a building within a horizontal distance of 10 feet (3 m). WARNING The barometric shall be in the same atmospheric pressure zone as the combustion air inlet to the furnace. Deviation from this practice will cause improper burner operation and may result in a fire hazard or injury. 7− The vent must not pass through a floor or ceiling. Clearances to single wall vent pipe should be no less than 6" (152 mm); more if local codes require it. 8− The vent may pass through a wall where provisions have been made for a thimble as specified in the Standards of the National Board of Fire Underwriters. See figure 17. CAUTION Do not store combustible materials near the furnace or supply air ducts. The material (such as paint, motor oil, gasoline, paint thinner, etc.) may ignite by spontaneous combustion creating a fire hazard. 9− The vent pipe should slope upward toward the chimney on horizontal run at least 1/4 inch (6 mm) to the foot (0.3 m) and should be supported by something other than the furnace, such as isolation hangers. See figure 18. 10− Extend the vent pipe into the chimney so that it is flush with the inside of the vent liner. Seal the joint between the pipe and the liner. WARNING This furnace is certified for use with type L" vent. B" vent must not be used with oil furnaces. NOTE−Oil burning equipment may be vented into an approved masonry chimney or type L vent. (Type L vent is similar in construction to type B gas vent except it carries a higher temperature rating and is constructed with an inner liner of stainless steel rather than aluminum). 11− The furnace shall be connected to a factory built chimney or vent complying with a recognized standard, or masonry or concrete chimney lined with a lining material acceptable to the authority having jurisdiction. Prior to installation of unit, make a thorough inspection of the chimney to determine whether repairs are necessary. Make sure the chimney is properly constructed and sized according to the requirements of the National Fire Protection Association. The smallest dimensions of the chimney should be at least equal to the diameter of the furnace vent connector. Make sure the chimney will produce a steady draft sufficient to remove all the products of combustion from the furnace. A draft of at least .04" w.c. (9.9 Pa) is required during burner operation. 1− Local building codes may have more stringent installation requirements and should be consulted before installation of unit. Page 17 WALL THIMBLE THIMBLE COMBUSTIBLE WALL VENT PIPE FIGURE 17 17− Vent connectors serving this appliance shall not be connected into any portion of mechanical draft systems operating under positive pressure. MASONRY CHIMNEY BAROMETRIC CONTROL* (IN EITHER LOCATION) LINER 18− Keep the area around the vent terminal free of snow, ice and debris. NOTE−If vent pipe needs to exit from side of cabinet, use the cross hairs (located on either side of the unit) to cut a 6" (152 mm) round hole. Attach finishing plate (provided) with four sheet metal screws to cover rough edges. CLEANOUT MASONRY CHIMNEY CLEANOUT *Barometric control may be installed in either vertical or horizontal section of vent pipe within 18" (457 mm) of vent outlet of furnace. FIGURE 18 12− When two or more appliances vent into a common vent, the area of the common vent should not be less than the area of the largest vent or vent connection plus 50% of the areas of the additional vent or vent connection. Chimney must be able to sufficiently vent all appliances operating at the same time. 13− The vent pipe shall not be connected to a chimney vent serving a solid fuel appliance or any mechanical draft system. 14− All unused chimney openings should be closed. 15− All vent pipe run through unconditioned areas or outside shall be constructed of factory built chimney sections. See figure 19. 16− Where condensation of vent gas is apparent, the vent should be repaired or replaced. Accumulation of condensation in the vent is unacceptable. FACTORY−BUILT CHIMNEY BAROMETRIC CONTROL* (IN EITHER LOCATION) Combustion and Ventilation Air (Confined and Unconfined Spaces) Until recently, there was no problem in bringing in sufficient amounts of outdoor air for combustion −− infiltration provided all the air that was needed and then some. In today’s homes built with energy conservation in mind, tight construction practices make it necessary to bring in air from outside for combustion. Consideration must also be given to the use of exhaust fans, appliance vents, chimneys and fireplaces because they force additional air that could be used for combustion out of the house. Unless outside air is brought into the home for combustion, negative pressure (pressure outside is greater than inside pressure) will build to the point that a down draft can occur in the furnace vent pipe or chimney. Combustion gases enter the living space creating a potentially dangerous situation. The importance of the previous paragraph cannot be overstated. Users may inadvertently block fresh air intakes after installation. In the absence of local codes concerning air for combustion and ventilation, the following section outlines guidelines and recommends procedures for operating oil furnaces in a manner that ensures efficient and safe operation. Special consideration must be given to combustion air needs as well as requirements for exhaust vents and oil piping. Combustion Air Requirements CAUTION FACTORY BUILT CHIMNEY *Barometric control may be installed in either vertical or horizontal section of vent pipe within 18" (457 mm) of vent outlet of furnace. FIGURE 19 Insufficient combustion air can cause headaches, nausea, dizziness or asphyxiation. It will also cause excess water in the heat exchanger resulting in rusting and premature heat exchanger failure. It can also cause property damage. All oil−fired appliances require air to be used for the combustion process. If sufficient amounts of combustion air are not available, the furnace or other appliance will operate in an inefficient and unsafe manner. Enough air must be provided to meet the needs of all fuel−burning appliances, as well as appliances such as exhaust fans which force air out of the home. When fireplaces, exhaust fans, or clothes dryers are used at the same time as the furnace, much more air is required to ensure proper combustion and to prevent a down− draft situation. Insufficient amounts of air also cause inPage 18 complete combustion which can result in sooting. Requirements for providing air for combustion and ventilation depend largely on whether the furnace is installed in an unconfined or confined space. EQUIPMENT IN CONFINED SPACE ALL AIR FROM INSIDE CHIMNEY OR OIL VENT Unconfined Space An unconfined space is an area such as a basement or large equipment room with a volume greater than 50 cubic feet (1.4 cubic meters) per 1,000 Btu (293 W) per hour of the combined input rating of all appliances installed in that space. This space also includes adjacent rooms which are not separated by a door. Though an area may appear to be unconfined, it might be necessary to bring in outdoor air for combustion if the structure does not provide enough air by infiltration. If the furnace is located in a building of tight construction with weather stripping and caulking around the windows and doors, follow the procedures outlined for using air from the outside for combustion and ventilation. Confined Space A confined space is an area with volume less than 50 cubic feet (1.4 cubic meters) per 1,000 Btu (293 W) per hour of the combined input rating of all appliances installed in that space. This definition includes furnace closets or small equipment rooms. When the furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space containing the furnace, the return air must be handled by ducts which are sealed to the furnace casing and which terminate outside the space containing the furnace. This is especially important when the furnace is mounted on a platform in a confined space such as a closet or small equipment room. Even a small leak around the base of the unit at the platform or at the return air duct connection can cause a potentially dangerous negative pressure condition. Air for combustion and ventilation can be brought into the confined space either from inside the building or from outside. WATER HEATER OIL FURNACE OPENINGS (To Adjacent Room) NOTE−Each opening shall have a free area of at least 1 square inch (6.4 square centimeters) per 1,000 Btu (293 W) per hour of the total input rating of all equipment in the enclosure, but not less than 100 square inches (614.5 square centimeters). FIGURE 20 Air from Outside If air from outside is brought in for combustion and ventilation, the confined space shall be provided with two permanent openings. One opening shall be within 12" (305 mm) of the top of the enclosure and one within 12" (305 mm) of the bottom. These openings must communicate directly or by ducts with the outdoors or spaces (crawl or attic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch (6.4 square centimeters) per 4,000 Btu (1172 W) per hour of total input rating of all equipment in the enclosure (See figures 21 and 22). When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch (6.4 square centimeters) per 2,000 Btu (586 W) per total input rating of all equipment in the enclosure (See figure 23). EQUIPMENT IN CONFINED SPACE ALL AIR FROM OUTSIDE (Inlet Air from Crawl Space and Outlet Air to Ventilated Attic) CHIMNEY OR OIL VENT VENTILATION LOUVERS (Each end of attic) Air from an Adjacent Space If the confined space housing the furnace adjoins space categorized as unconfined, air can be brought in by providing two permanent openings between the two spaces. Each opening must have a minimum free area of 1 square inch (6.4 square centimeters) per 1,000 Btu (293 W) per hour of the total input rating of all fuel−fired equipment in the confined space. Each opening must be at least 100 square inches (614.5 square centimeters). One opening shall be within 12" (305 mm) of the top of the enclosure and one opening within 12" (305 mm) of the bottom (See figure 20). Page 19 OIL FURNACE OUTLET AIR VENTILATION LOUVERS (For unheated crawl space) WATER HEATER INLET AIR NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (6.4 square centimeters) per 4,000 Btu (1172 W) per hour of the total input rating of all equipment in the enclosure. FIGURE 21 EQUIPMENT IN CONFINED SPACE ALL AIR FROM OUTSIDE (All Air Through Ventilated Attic) CHIMNEY OR OIL VENT CAUTION Combustion air openings in the front of the furnace must be kept free of obstructions. Any obstruction will cause improper burner operation and may result in a fire hazard or injury. VENTILATION LOUVERS (Each end of attic) OUTLET AIR CAUTION INLET AIR (Ends 12" above bottom) OIL FURNACE The barometric shall be in the same atmospheric pressure zone as the combustion air inlet to the furnace. Deviation from this practice will cause improper burner operation and may result in a fire hazard or injury. WATER HEATER NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (6.4 square centimeters) per 4,000 Btu (1172 W) per hour of the total input rating of all equipment in the enclosure. FIGURE 22 EQUIPMENT IN CONFINED SPACE ALL AIR FROM OUTSIDE CHIMNEY OR OIL VENT WATER HEATER OUTLET AIR OIL FURNACE Direct Connection of Outdoor Air for Combustion The Beckett AFII burner was designed to allow for direct air intake piping (4" [102 mm]). The maximum equivalent length of pipe is 70 feet (21.3 m). A 90 elbow equals 6feet (1.8 m). To convert the AFII burner from confined space to outside combustion air, simply remove the three screws attaching the inlet air scoop to the burner and insert 4" (102 mm) direct air intake piping. The use of a barometric relief placed in the intake pipe is recommended when outdoor combustion air is directly connected to the burner. This will allow confined space air to be used as combustion air in the event that the opening to the outdoor air becomes blocked. Using a barometric relief in the intake will reduce the chance of sooting. INLET AIR CAUTION DO NOT USE a barometric draft relief in exhaust vent pipe if outdoor combustion air is connected directly to the burner. The only exception are barometric draft reliefs as required by FIELD or TJERNLUND power vents. NOTE−Each air duct opening shall have a free area of at least one square inch (6.4 square centimeters) per 2,000 Btu (586 W) per hour of the total input rating of all equipment in the enclosure. If the equipment room is located against an outside wall and the air openings communicate directly with the outdoors, each opening shall have a free area of at least one square inch (6.4 square centimeters) per 4,000 Btu (1172 W) per hour of the total input rating of all other equipment in the enclosure. FIGURE 23 When ducts are used, they shall be of the same cross−sectional area as the free area of the openings to which they connect. The minimum dimension of rectangular air ducts shall be no less than 3" (76 mm). In calculating free area, the blocking effect of louvers, grilles, or screens must be considered. If the design and free area of protective covering is not known for calculating the size opening required, it may be assumed that wood louvers will have 20 to 25 percent free area and metal louvers and grilles will have 60 to 75 percent free area. Louvers and grilles must be fixed in the open position or interlocked with the equipment so that they are opened automatically during equipment operation. Removal of Unit from Common Venting System In the event that an existing furnace is removed from a venting system commonly run with separate appliances, the venting system is likely to be too large to properly vent the remaining attached appliances. The following test should be conducted while each appliance is in operation and the other appliances not in operation remain connected to the common venting system. If venting system has been installed improperly, the system must be corrected as outlined in the previous section. 1− Seal any unused openings in the common venting system. 2− Visually inspect venting system for proper size and horizontal pitch and determine there is no blockage or restriction, leakage, corrosion or other deficiencies which could cause an unsafe condition. Page 20 3− Insofar as is practical, close all building doors and windows and all doors between the space in which the appliances remaining connected to the common venting system are located and other spaces of the building. Turn on clothes dryers and any appliances not connected to the common venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed. Do not operate a summer exhaust fan. Close fireplace dampers. 4− Following the lighting instruction on the unit, place the appliance being inspected in operation. Adjust thermostat so appliance will operate continuously. 5− Test for spillage using a draft gauge. 6− After it has been determined that each appliance remaining connected to the common venting system properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other fuel burning appliance to their previous condition of use. (152 mm) is permissible. Calculate the equivalent vent pipe footage from the furnace to the mechanical vent system (Tjernlund or Field Controls) by adding the straight vent pipe length and the equivalent elbow lengths together. The barometric draft control must be used in horizontal (sidewall) venting system. It must be located within 18" (457 mm) of the furnace vent outlet. See figure 24 for barometric draft control location. III−START-UP A−Preliminary and Seasonal Checks 1− Inspect electrical wiring, both field and factory installed for loose connections. Tighten as required. 2− Check line voltage. Voltage must be within range listed on the nameplate. If not, consult the power company and have voltage condition corrected before starting unit. B−Heating Start-Up FOR YOUR SAFETY READ BEFORE LIGHTING WARNING 7− If improper venting is observed during any of the above tests, the common venting system must be corrected. Do not attempt to start the burner when excess oil has accumulated in the chamber, when the furnace is full of vapor or when the combustion chamber is very hot. Horizontal Venting 1− Set thermostat for heating demand. HORIZONTAL VENTING BAROMETRIC CONTROL* 2− Turn on electrical supply to unit and open all shut-off valves in the oil supply line to the burner.. CONTROL FOR HORIZONTAL VENTING 3− Check air adjustment dial on the right side of the burner (see figure 9). Set according to table 4. *When using indoor air, barometric control must be installed in the horizontal venting system and located within 18" (457 mm) of vent outlet of furnace. When using direct connection, barometric control must be installed in the intake air pipe. FIGURE 24 The O23 is approved for horizontal venting with the following mechanical vent systems: Tjernlund (sideshot) #SS1C and Field Controls #SWG−5 with the CK−61 control kit. Refer to manufacturers’ installation instructions for proper installation procedures and service parts information. Do not common vent with any other appliance when using sidewall vent system. Maximum permissible vent length is 70 equivalent feet (21.3 m). Minimum length is 15 equivalent feet (4.6 m). Each 90 elbow is equal to 6 feet (1.8 m) of straight pipe, each 45 elbow is equal to 3 feet (0.9 m) of straight pipe. Minimum vent pipe diameter is 4" (102 mm). Vent pipe of 5" (127 mm) and 6" 4− On single line applications the oil pump must be primed by bleeding the oil line. Open air bleed port and start burner. A hose may be attached to direct oil into a container. After last bubble is seen, bleed pump for 15 seconds. Hurried bleeding will impair efficient unit operation. Close port to stop bleeding. Single line installations must be absolutely air tight to prevent leaks or loss of prime. 5− If burner stops after flame is established, repeat the bleeding procedure. NOTE−Air bleeding is automatic on two line applications; however, opening air bleed port will allow a faster bleed. Run return line back to tank and terminate three to four inches above the inlet line. Failure to bleed the system may cause air to be introduced into the system resulting in a loss of prime. 6− If the burner does not start immediately, check the safety switch on the burner primary control. 7− If burner fails to light again, refer to the troubleshooting section in the back of this manual. 8− Proceed to section IV to complete start up. C−Safety or Emergency Shutdown Turn off unit power. Close all shut-off valves in the oil supply line. Page 21 D−Extended Period Shutdown Turn off thermostat or set to UNOCCUPIED" mode. Close all shut-off valves in the oil supply line to guarantee no oil leaks into burner. Turn off all power to unit. All access panels, covers and vent caps must be in place and secured. IV−HEATING SYSTEM SERVICE CHECKS A−Oil Piping All oil supply piping (factory and field) must be carefully checked for oil leaks. B−Electrode Adjustment When adjusting the electrode, use the AFII multipurpose gauge (Beckett part # T−500) packaged with each oil furnace, also available from Beckett. To check that the nozzle is approximately centered with the head inside diameter, align the center mark of the gauge with the center of the nozzle orifice, as shown in figure 27, and move the gauge from side to side at several points. Be careful not to scratch the nozzle surface. The Z" or zero dimension is important because it locates the nozzle for the precise relationship with the combustion head. To set the Z" dimension, position the gauge as shown in figure 27 and loosen the nozzle line electrode assembly so that it can be moved forward or backward in the air tube until the nozzle becomes flush against the gauge. Tighten the nozzle line escutcheon plate screw (shown in figure 9) to lock this Z" dimension securely. To set the electrode tip gap spacing, position the gauge as shown in figure 25. Align the center mark with the nozzle and adjust the electrodes to the two outer marks (1/8" [3mm] to 1/16" [2mm] minimum). AFII NOZZLE CENTERING AFII ELECTRODE TIP GAP FIGURE 25 To position the electrode tips beyond the face of the nozzle and above the center line, position the gauge as shown in figure 26. Align the center mark with the nozzle and adjust the electrodes to the AC cross marks. AFII ELECTRODE POSITIONING FIGURE 26 FIGURE 27 C−Pressure Check On −1 through −4 units use either the gauge port or nozzle port to check operating pressure. On −5 units use the nozzle port (−5 unit pumps are not equipped with gauge port). The pump is factory set at 100 psig (689.5 kPa) for the O23Q2−70 and 140 psig (965.3 kPa) for all other O23, OHR23, and OF23 units but is adjustable (see figure 28). Never operate the pump in excess of 10 psig (69 kPa) above set point. Average nozzle cutoff pressure is 80 psig (551.6 kPa). To check the cutoff pressure install a pressure gauge in nozzle port. For −5 units use the same gauge used for operating pressure. Run the burn- Page 22 er for a short period and then turn off. The gauge shows cutoff pressure. OIL PUMP PRESSURE CHECK *PRESSURE GAUGE 2−Overfire Draft **REGULATE PRESSURE NOT SHOWN (beside the inlet port) PRESSURE GAUGE PORT (1/8" [3mm]) This test should be taken with the burner in operation. Remove the screw from the center of the center inspection port. Insert your draft gauge into the hole. A reading of the overfire draft should be 0.02" w.c. (5.0 Pa) less than the reading found in the vent connector. If a positive reading is seen at this point, the secondary heat exchanger may be sooted or to much air may be entering into the heat exchanger from the combustion fan. Adjustments to the combustion fan can be made using the air adjustment dial. INLET PORT SHOWN (1/4" [6mm]) NOZZLE PORT (1/8" [3mm]) Oil furnace installations also require careful inspection to make sure the chimney is in good condition and can accommodate the products of combustion. The temperature in unconditioned space will also affect the draft if long vent connectors are allowed to get too cold. 3−Smoke Test The smoke test should be taken at hole drilled in step 1. Using a smoke test gun adjust the air inlet shutter so that you will have just a trace of smoke. Somewhere between a 0 and #1 smoke. This is the starting point. Do not stop here. After the smoke test take a CO sample. C.S.A. requires no more than 400ppm. However, a properly installed unit under normal operating conditions should not read more than 50ppm. BLEED PORT INLET PORT (1/4" [6mm]) 4−CO2 Test RETURN PORT (1/4" [6mm]) 1/16" (2mm) BY-PASS PLUG INSERT FOR TWO-PIPE SYSTEM (use 5/32" [4mm] allen wrench) *PRESSURE CHECKS: NORMAL OPERATING PRESSURE IS 100 PSIG (689.5 kPa) FOR THE 023Q2-70 AND 140 PSIG (965.3 kPa) FOR ALL OTHER O23, OHR23, AND OF23 UNITS. NOZZLE CUTOFF PRESSURE IS APPROXIMATELY 80 PSIG (551.6 kPa). **TO ADJUST PRESSURE: INSERT STANDARD SCREWDRIVER. TURN COUNTERCLOCKWISE BELOW DESIRED PRESSURE, THEN TURN CLOCKWISE TO SET DESIRED PRESSURE. FIGURE 28 D−Burner Adjustment The following instructions are essential to the proper operation of O23 series oil furnaces. To prevent sooting, these instructions must be followed in sequence: NOTE−All w.c. measurements are below atmospheric pressure (negative readings). 1−Draft This test should be taken at the vent connector between the breaching and the barometric damper. Generally a 1/4" (6 mm) hole will need to be drilled for the draft gauge to be inserted into the vent connector. A minimum of 0.03" w.c. (7.5 Pa) draft must be established without the burner in operation. With the burner in operation, the draft should be 0.04" w.c. (9.9 Pa) to 0.05" w.c. (12.4 Pa). This is VERY critical to the flame retention head burners. Again to be taken at the vent connector pipe. With the unit firing at a trace of smoke, test for percentage of CO 2 in the vent gas. From the results of this test, a window of operation" will be determined. This window of operation establishes some tolerance. The tolerance the installer builds in provides room within the set-up for those things which might affect combustion. Those things which might affect combustion can then do so without causing the unit to start sooting/smoking. Things which might affect combustion include a nozzle going bad, draft that changes during different climatic conditions, dirty oil, dirt obstructing the air inlet, etc. To build in a window of operation," set up the burner to be 2% less in CO2. For example, if you find a reading of 12% CO2, adjust the air inlet shutter to increase the air and drop the CO2 to 10%. 5−Retest the Smoke With a drop in the CO2 and increase in the air you should see that the smoke has returned to 0. 6−Retest the Overfire Draft This test serves to confirm that you have not increased the air too much. Again you do not want a positive pressure at the test port. It should still be 0.02" w.c. (5.0 kPa) less than the draft from the vent connector. You may need to increase the stack draft by adjusting the barometric damper. Page 23 7−Stack Temperature Take a stack temperature reading in the vent connector pipe. Subtract the room air temperature from the stack temperature. This will give you the net stack temperature. Using efficiency charts provided in most CO2 analyzers you can tell at what efficiency the furnace is operating. IGNITION TRANSFORMER SCREWS IGNITION TRANSFORMER V−DISASSEMBLY PROCEDURES Use the following procedures to access and disassemble the burner or blower if service to either is needed. WARNING Electric shock hazard. Can cause injury or death. Before attempting to perform any service or maintenance, turn the electrical power to unit OFF at disconnect switch(es). Unit may have multiple power supplies. SCREWS SCREW TO OPEN ACCESS DOOR ACCESS DOOR A−Disassembling Burner The burner assembly is attached to the vestibule panel by three nuts. Slots are provided in the mounting flange for removing the burner assembly from the vestibule. By loosening the nuts and by turning the whole burner assembly counterclockwise (figure 29), the entire burner assembly will come out of the furnace. There is adequate wire to remove the burner without disconnecting wires. Once removed, just turn the burner around in the vest panel area. FIGURE 30 2−Removing Cad Cell NOTE−Before disassembling any part of the burner, turn off power and oil supply to the burner. 2− The cad cell will be located on the right side of the chassis wall hung on a bracket. See figure 31. 3− Remove by loosening the screw on the bracket. 4− Disconnect the leads from the primary control terminal strip. BURNER REMOVAL First, loosen three nuts which attach burner to vest panel. nuts 1− Loosen the screw to the back access door until door opens. See figures 30 and 31. Next, rotate burner counterclockwise on slots then pull toward you. CAD CELL CAD CELL FIGURE 29 SCREW 1−Removing Ignition Transformer 1− Remove all four screws located on the side of the ignition transformer. See figure 30. 2− Lift the ignition transformer straight up. Do not hinge back. Porcelain isolators may break if hinged back. NOTE−When testing the solid state transformer, do not use a transformer tester designed for iron magnet transformers. Damage to the tester may result Page 24 ACCESS DOOR FIGURE 31 3−Removing Gun Assembly 5−Removing Motor / Combustion Air Blower 1− Loosen the screw to the back access door until door opens. See figures 30 and 31. 1− Disconnect supply line at pump and oil line at gun assembly as shown in figure 33. 2− Remove flare fitting nut on oil line at pipe adjusting plate located on outside of blower housing. 2− If motor and blower wheel are to be removed away from the burner, disconnect motor wiring harness from the primary control. If the motor and blower wheel only need to be removed to check and clean, there is adequate wire in the motor wiring harness without disconnecting. 3− Remove nut connecting oil line to gun assembly oil line. See figure 32. 4− Remove gun assembly from air tube. 5− Remove transformer leads. 3− Loosen two bolts securing motor to blower housing. Key hole slots are provided for easy removal. See figure 34. NOTE−When reinstalling gun assembly, check and set position and Z" dimension as shown in figure 27. 4− Loosen allen set screw holding the blower wheel onto the motor shaft and remove blower wheel. NOTE−When reconnecting gun assembly oil line, make sure flat side of nut goes first. COMBUSTION AIR MOTOR & WHEEL GUN ASSEMBLY BLOWER MOTOR BOLT Remove both nuts Gun Assembly BOLT FIGURE 32 PUMP FIGURE 34 4−Removing Oil Pump 1− Disconnect supply line at pump and oil line at gun assembly. NOTE−When reinstalling blower wheel use the AFII multipurpose gauge (Beckett part # T−500) to space the distance from the back of the blower wheel to the face of the motor (1/16" [2 mm]). 2− Loosen two bolts on sides of pump securing pump to blower housing. See figure 33. B−Removing Indoor Blower 3− Detach pump and motor shaft coupler from pump. 1− Turn off electric power to furnace. 2− Remove blower access door. OIL PUMP 3− Remove two screws located in the front blower rails. See figure 35. 4− Pull blower forward enough to disconnect the motor leads and the secondary limit on OHR units. OIL LINE GUN ASSEMBLY ENTRANCE 5− Pull blower assembly out and place to the side. SUPPLY LINE INLET INDOOR BLOWER (OHR23 SHOWN) SECONDARY LIMIT (OHR only) MOTOR LEADS BOLT BOLT SCREW OIL PUMP SCREW MOTOR FIGURE 33 FIGURE 35 Page 25 VI−TYPICAL OPERATING CHARACTERISTICS A−Blower Operation and Adjustment NOTE− The following is a generalized procedure and does not apply to all thermostat controls. 1− Blower operation is dependent on thermostat control system. 2− Generally, blower operation is set at thermostat subbase fan switch. With fan switch in ON position, blower operates continuously. With fan switch in AUTO position, blower cycles with demand. 3− In all cases, blower and entire unit will be off when line voltage is disconnected. B−Temperature Rise 6− Select the desired speed for heating and cooling (H = high, M = medium, L = Low). Table 9 lists the factory connections. 7− If cooling and heating speeds are to be the same speed, disconnect and discard the cooling wire. Jumper the A and H spade terminals on the BCC2 and BCC3 board and jumper COOL to HEAT on the ST9103A board. Run the heating terminal wire from the BCC2, BCC3 and ST9103A board to the correct spade connection on the blower motor. 8− To achieve low speed on continuous blower on the ST9103A board, run a FIELD supplied wire (16 AWG or larger) from blower motor low speed terminal to the ST9103A CONT terminal. Temperature rise for O23, OHR23, and OF23 units depends on unit input, blower speed, blower horsepower and static pressure. The blower speed must be set for unit operation within the range of AIR TEMP. RISE °F" listed on the unit rating plate. TABLE 9 BLOWER SPEED SELECTION Factory Connected Speed Taps Speeds Unit Available Cool Heat (Black) (Red) Q2-70 M L 3 Q3-105/120 H M 3 Q5-140/154 H M 3 To Measure Temperature Rise: 1. Place plenum thermometers in the supply and return air plenums. Locate supply air thermometer in the first horizontal run of the plenum where it will not pick up radiant heat from the heat exchanger. 2. Set thermostat to highest setting. D−External Static Pressure 3. After plenum thermometers have reached their highest and steadiest readings, subtract the two readings. The difference should be in the range listed on the unit rating plate. If the temperature is too low, decrease blower speed. If temperature is too high increase blower speed to reduce temperature. To change blower speed see Blower Speed section. 1. Measure tap locations as shown in figure 36. C−Blower Speed Blower speed selection is accomplished by changing the wires at the blower motor spade connector. To Change Blower Speed 1− Turn off electric power to furnace. 2− Remove blower access door. 3− Remove two screws located in the front blower rails. 4− Pull blower assembly forward enough to disconnect the motor leads. 5− Disconnect heating (red) and / or Cooling (black) wire(s) from the motor. The common (white) wire always remains on C = common. 2. Punch a 1/4" (6 mm) diam- STATIC PRESSURE TEST eter hole in supply and return air plenums. Insert MANOMETER manometer hose flush with inside edge of hole or insulation. Seal around the hose with permagum. ConOIL UNIT nect the zero end of the maFIGURE 36 nometer to the discharge (supply) side of the system. On ducted systems, connect the other end of manometer to the return duct as above. For systems with non−ducted returns, leave the other end of the manometer open to the atmosphere. 3. With only the blower motor running and the evaporator coil dry, observe the manometer reading. Adjust blower motor speed to deliver the air desired according to the job requirements. 4. Pressure drop must not exceed 0.5" W.C. (124.3 Pa). 5. Seal around the hole when the check is complete. Page 26 VII−MAINTENANCE C−Annual Burner Maintenance 1− Replace the oil supply line filter. CAUTION 2− Remove and clean the pump strainer if applicable. Never operate unit with access panels to the blower compartment off or partially open. 3− Replace the nozzle with an equivalent nozzle. 4− Check the pump pressure when changing nozzle. A−Filters If throw-away type filters are used, check monthly and replace when necessary to assure proper furnace operation. Replace filters with like kind and size. If reusable type filters are used, check monthly and clean with water and mild detergent when necessary. When dry, they should be sprayed with filter handicoater prior to reinstallation. Filter handicoater is RP Products coating no. 418 and is available as Lennox part no. P-8-5069. B−Cleaning Heat Exchanger 5− Clean and inspect the electrodes for damage, replacing any that are cracked or chipped. 6− Clean the combustion head of all lint and soot. 7− Inspect the transformer cables and connectors. 8− Remove and clean the cad cell. 9− Clean the blower wheel and the air control of any lint. 10− Check all wiring for secure connections or insulation breaks. 11− Re-adjust the burner as described in section IV of this manual. NOTE−Use papers or protective covering in front of furnace while cleaning furnace. Cleaning the heat exchanger is made easier with a heat exchanger clean-out kit ABRSH380 (catalog # 35K09) available from Lennox. 1− Remove vent pipe from furnace. 2− Remove locking screws and caps from cleanout tubes. Remove vent access elbow. 3− Using a long spiral wire brush, sweep down the outer drum of the heat exchanger. Then using the hose attachment, vacuum out loose debris. 4− Remove locking screw and cap from the observation tube and with the spiral wire brush, reach upward toward the rear of the heat exchanger to clean out the crossover tube. NOTE− Do not attempt to clean the combustion chamber. It can be easily damaged. 5− Replace the cleanout caps and vent access elbow. Make sure locking screws are secure. 6− Brush out and vacuum the vent outlet area of the outer drum and replace vent pipe. 7− Clean around the burner, blower deck and vestibule area. D−Supply Air Blower 1- Disconnect power to unit. 2- Check and clean blower wheel. 3- Motors are prelubricated for extended life; no further lubrication is required. E−Vent Pipe The vent pipe should be inspected annually. Remove and clean any soot or ash found in the vent pipe. Vent pipe deteriorates from the inside out and must be disconnected in order to check thoroughly. Inspect pipe for holes or rusted areas. Inspect the vent control device and replace if found defective. Check for tightness and to make sure there is no blockage or leaks. F−Electrical 1- Check all wiring for loose connections. 2- Check for correct voltage at unit (unit operating). 3- Check amp-draw on blower motor. Motor Nameplate_________Actual_________ 4- Check to see that heat is operating. Page 27 VIII−WIRING DIAGRAMS AND SEQUENCE OF OPERATIONS 2 4 8 12 3 7 7 5 9 8 12 4 1 6 10 12 4 9 O23 / OHR23 / OF23−1 through −4 UNIT OPERATION SEQUENCE: 1. When disconnect is closed, 120V is routed to the blower control board BCC2 (A15). The BCC2 feeds line voltage to transformer (T1). 2. T1 supplies 24VAC to the burner control (A3). In turn, A3 supplies 24VAC to A15, which supplies the indoor thermostat (not shown) with 24VAC. 3. When there is a call for heat, W1 of the thermostat energizes W of the A15 board with 24VAC. 4. A15 energizes combustion air blower relay (K13). When K13-2 closes, assuming primary limit (S10) and [secondary limit (S21) in OHR units only] are closed, 24VAC is routed to 1K, which closes 1K1 and 1K2. When 1K2 closes combustion air blower / pump (B6) is energized. Simultaneously 24VAC is routed through the blower relay (K36). When K36-1 closes blower motor (B6) is energized on heating speed. 5. When 1K2 closes the electronic ignitor is energized causing a 14,000VAC spark, igniting the burner. When 1K1 closes the solid state switch and cad cell are energized. When the cad cell senses light the solid state switch de-energizes the safety heater, keeping the burner operating. 6. A15 energizes accessory relay (K109). When K109-1 closes the accessory terminal on the A15 board is energized with 120VAC. 7. When heat demand is satisfied, W1 of the thermostat de-energizes W of the ignition control. W de-energizes K13 in turn de-energizing 1K. When 1K is de-energized B6 and A73 stop immediately. The indoor blower runs for a designated fan off" period (90−330 seconds) as set by jumper on BCC2 control. 8. When there is a call for cooling, Y1 of the thermostat energizes Y and G of the A15 board with 24VAC. 9. A15 energizes blower relay K3. When K3-1 closes B3 starts on the speed set for cooling. 10. A15 energizes accessory relay K109. When K109-1 closes the accessory terminal on the A15 board is energized with 120VAC. 11. Provided that condensing unit is connected to Y terminal, cooling will start. 12. When cooling demand is satisfied, Y1 of the thermostat de-energizes Y and G. The indoor blower and condensing unit stops immediately. Page 28 1 6 1 9 2 4 6 7 5 9 10 10 3 4 8 O23 / OHR23 / OF23−5 UNIT OPERATION SEQUENCE: 1. When disconnect is closed, 120V is routed to the blower control board (A15). The blower control board feeds line voltage to transformer (T1). 2. When there is a call for heat, W1 of the thermostat energizes W of the A15 board with 24VAC. 3. A15 energizes combustion air inducer B6 assuming primary limit (S10) and [secondary limit (S21) in OHR units only] are closed. 4. Burner control A3 energizes the electronic ignitor causing a 20,000VAC spark . Burner motor (B6) and pump valve (L35) are delayed for a 15 second pre−purge. The pre−purge is followed by a 15 second trial for ignition. 5. After the pre−purge and trial for ignition (30 seconds) voltage passes through contactor K1 the energizing the indoor blower B3 on heating speed. 6. When heat demand is satisfied, W1 of the thermostat de-energizes W of the ignition control. Combustion air inducer B6 is de−energized. The indoor blower runs for a designated fan off" period (60−150 seconds) as set delay switch on blower control. 7. When there is a call for cooling, Y1 of the thermostat energizes Y and G of the A15 board with 24VAC. 8. A15 energizes relay K2. When K2 contacts close, the indoor blower B3 energizes on cooling speed. 9. When cooling demand is satisfied, Y1 of the thermostat de-energizes Y and G. The indoor blower and condensing unit stops immediately. 10. When there is a call for continuous fan the indoor blower (B3) is energized on cool speed. If blower control board is wired for continuous fan, the indoor blower will energize on low speed and remain energized after thermostat demand is satisfied. Page 29 1 3 2 TJERNLUND HORIZONTAL VENTING SYSTEM (SIDESHOT) OPERATION SEQUENCE: 1. When 1K2 closes, 120VAC is routed through the relay/timer, electronic ignitor (A73), and the limit switch. 2. The relay/timer energizes the venter motor. 3. After the venter motor establishes a draft, the N.O. fan proving switch closes completing the circuit to the burner motor. 1 2 3 FIELD CONTROL HORIZONTAL VENTING SYSTEM OPERATION SEQUENCE: 1. When 1K2 closes, 120VAC is routed through the relay. 2. The relay energizes the venter motor. 3. After the venter motor establishes a draft, the N.O. fan proving switch closes, completing the circuit to the burner motor and electronic ignitor (A73). Page 30 IX−TROUBLESHOOTING Burner failure or improper unit operation can be caused by various conditions. Often the problem can be solved by a logical process of checks and eliminations. The following pages lists a few common problems along with the solutions. Carefully check the most obvious items first before proceeding to more involved procedures. COMMON CHIMNEY VENTING PROBLEMS Problem: Top of chimney lower than surrounding objects. Solution:Extend chimney above all objects within 10 feet (3 meters). Problem: Chimney cap or ventilator. Solution: Remove. Problem:Coping restricts opening. Solution:Make opening as large as inside of chimney. Problem:Obstruction in chimney. Obstruction can be found by light and mirror reflecting conditions in chimney. Solution: Use weight to break and dislodge. Problem: Joist projecting into chimney. Can be found by lowering a light on an extension cord. Solution: Must be handled by a competent brick contractor. Problem: Break in chimney lining. Can be found by Smoke test-build smudge fire blocking off other opening and watching for smoke to escape. Solution: Must be handled by a competent brick contractor. Problem: Offset. Can be found by lowering light on extension. Solution: Change to straight or long offset. Problem: Collection of soot at narrow space in the flue opening. Can be found by lowering light on extension cord. Problem: Clean out with weighted brush or bag of loose gravel on end of line. Problem: Two or more openings into same chimney. Can be found by inspection. Solution: The least important opening must be closed FIREPLACE DAMPER Problem: Loose−seated pipe in flue opening. Detected by smoke test. Solution: Leaks should be eliminated by cementing all pipe openings. FIREPLACE Problem: Smoke pipe extends into chimney. Detected by measurement of pipe from within or observation of pipe by means of a lowered light. Solution: Length of pipe must be reduced to allow end of pipe to be flush with inside of tile. ASH DUMP Problem: Failure to extend the length of the flue partition down to the floor. Detected by inspection or smoke test. Solution: Extend partition to floor level. Problem:Loose fitting clean−out door. Detected by smoke test. Solution: Close all leaks with cement. Page 31 START YES BCC2 / BCC3 TROUBLESHOOTING FLOWCHART DOES UNIT OPERATE? NO IS 24VAC ACROSS R & C? NO CHECK: 1−UNIT POWER 2−TRANSFORMER 3−LIMIT SWITCH YES JUMPER ACROSS SCREWS R & G REPLACE BCC2 NO IS 120VAC ACROSS N & ACC? YES IS BLOWER RUNNING ON HIGH SPEED? NO IS 120VAC ACROSS N & A? CHECK BLOWER WIRING AND BLOWER JUMPER ACROSS R &W (REMOVE R & G JUMPER) IS UNIT LIT? CHECK: 1−PRIMARY CONTROL 2−IGNITION TRANSFORMER 3−FUEL PUMP 4−ELECTRODES 5−LIMIT SWITCH(ES) NO YES REPLACE BCC2 IS 120VAC ACROSS N & ACC? IS BLOWER RUNNING ON LOW SPEED, 45 SEC. AFTER FURNACE LIGHTS? YES END OF TEST AFTER THE SELECTED TIME, DOES THE BLOWER TURN OFF? NO IS 120VAC ACROSS N & H? NO YES REMOVE R&W JUMPER YES REPLACE BCC2 YES YES NO NO IS 24VAC ACROSS C & V? NO NO REPLACE BCC2 Page 32 CHECK WIRING YES CHECK BLOWER WIRING AND BLOWER YES REPLACE BCC2 Troubelshooting: Blower Control ST9103A Action Thermostat calls for heat. (W terminal is energized.) System Response ST9103A closes oil primary control T−T connections. Ignition system and oil primary control start the furnace. Oil flows as long as oil primary control senses flame. Burner motor is energized and heat fan on delay timing begins. When timing is complete, the circulating fan is energized at heat speed and warm air is delivered to the controlled space. Thermostat ends call for heat. (W terminal is de−energized.) Oil primary control is de−energized, terminating the burner cycle. Heat fan off delay timing begins. When timing is complete, the circulating fan is de−energized. ST9103A returns to standby mode (oil primary control and circulating fan are off). Burner fails to light. Oil primary control locks out within lockout timing (timing depends on oil primary control). Burner motor is de−energized. If heat fan has started, it continues through the selected delay off period. Established flame fails. Burner motor is de−energized and oil primary control goes into recycle mode. If selected heat fan off delay is longer than the recycle delay timing, the heat fan continues to run through the next trial for ignition. Thermostat begins call for cool. (G and Y terminals are energized.) Circulating fan is energized at the cool speed. Thermostat ends call for cool. (G and Y terminals are de−energized.) Circulating fan and cooling compressor turn off immediately. Thermostat begins call for fan. (G terminal is energized.) Circulating fan is energized immediately at cool speed. Thermostat ends call for fan. (G terminal is de−energized.) Circulating fan is de−energized. Limit switch string opens. Oil primary control shut off the burner. Cooling compressor turns on immediately. ST9103A may be factory−configured to operate heat speed in this mode. Circulating fan is energized immediately at heat speed. ST9103A opens oil primary control T−T connections. Circulating fan runs as long as limit string stays open. If there is a call for cooling or fan, the circulating fan switches from heat speed to cool speed. Limit switch string closes. ST9103A begins heat fan off delay sequence. Circulating fan turns off after the selected heat fan off delay timing. ST9103A closes oil primary control T−T connections. Oil primary control is energized, initiating burner light off. Continuous circulating fan is connected. (Optional connectors are available for separate circulating fan speed tap.) Circulating fan is energized at low speed when there is no call for heat, cool or fan. Electronic air cleaner is connected. (Optional connectors are available for 120 Vac electronic air cleaner.) Electronic air cleaner (EAC) connections are energized when the heat or cool speed of the circulating fan is energized. EAC connections are not energized when the optional continuous fan terminal is energized. Humidity control is connected. (Optional connectors are available for 120 Vac humidifier.) Humidifier connections are energized when the burner motor is energized. If fan operation is required by a call for heat, cool, or fan, the ST9103A switches off the continuous fan speed tap before energizing the other fan speed. Page 33 Troubleshooting O23 / OHR23 / OF23 −1 through −4 Units Burner fails to start. Source Thermostat Safetyy Overloads Power Thermostat CAD Cell Primary Control Burner Procedure Check thermostat settings. Check burner motor, primary safetyy control, & auxiliaryy limit it h switch. Check furnace disconnect switch & main disconnect. Touch jumper wire across thermostat ostat terminals te a s on o primary p ay control. If burner starts, then fault is in the thermostat circuit circuit. Disconnect the flame detector wires att the control. i th primary i t l If the burner starts, fault is in the detector circuit. Place trouble light between the black and white leads. No light indicates that no power is going to the control. Causes Correction Thermostat in OFF or COOL Switch to HEAT. Thermostat is set too low Turn thermostat to higher temperature. Burner motor overload tripped Push reset button pump motor. Primary control tripped on safety Reset primary control. Auxiliary limit switch tripped on safety Reset auxiliary limit. Open switch Close switch. Blown fuse or tripped circuit breaker Replace fuse or reset circuit breaker. Broken or loose thermostat wires Repair or replace wires. Loose thermostat screw connection Tighten connection. Dirty thermostat contacts Clean contacts. Thermostat not level Level thermostat. Faulty thermostat Replace thermostat. Flame detector leads are shorted Separate leads. Flame detector exposed to light Seal off false source of light. short circuit in the flame detector Replace detector. Primary or auxiliary control switch is open Check adjustment. Set the maximum setting. Jumper terminals; if burner starts, switch is faulty, replace control. Open circuit between disconnect switch and limit control Trace wiring and repair or replace it. Low line voltage or power failure Call the power company. Place trouble light between the orange and white leads. No light indicates faulty control. Defective internal control circuit Replace the control. Place the trouble light between the black and white leads to the burner motor. No light indicates that no power is getting to the motor. Blown fuse Replace the fuse. Binding burner blower wheel Turn off power and rotate the blower wheel by hand. If seized, free the wheel or replace the fuel pump. Place trouble light between the black and white leads to the blower motor. Light indicates power to the motor and burner fault. Sized fuel pump Defective burner motor Page 34 Replace the motor. Burner starts, but no flame is established. Source Oil Supply Procedure No oil in tank Fill tank. Coat dip stick with litmus paste and insert into bottom of tank. Water in oil tank If water depth exceeds 1 inch, pump or drain water. Listen for pump whine. Tank shut−off valve closed Open valve. Oil line filter is plugged Replace filter cartridges. Kinks or restriction in oil line Repair or replace oil line. Plugged fuel pump strainer Clean strainer or replace pump. Oil Filters O te s & Oil O Line e Open bleed valve or gauge port. Start the burner burner. No oil or milky oil indicates loss or prime. Nozzle Correction Check tank gauge or use dip stick. Listen for pump whine. Oil Pump P Causes Install pressure p g gauge g on p pump p and d read d pressure. Should Sh ld nott be less than 140 psi. Disconnect ignition leads. Observe the oil spray (gun assemassem bly must be removed from unit). spect the t e nozzle o e for o plugged p ugged Inspect orifice or carbon build−up around orifice. Locate and correct leak. Air leak in oil supply line Tighten all connections. Pump is partially or completely frozen. No pressure and the motor locks out on overload. Replace pump. Coupling disengaged or broken − no pressure Re−engage or replace coupling. Fuel pressure too low Adjust to 100 psi. Nozzle orifice plugged Nozzle strainer plugged Replace nozzle with the same size, spray angle, and spray type. type Poor or off center spray Fouled or shorted electrodes Dirty electrodes and leads Clean electrode leads. leads Eroded electrode tips Improper electrode gap spacing Ignition Electrodes IIgnition iti Transformer B Burner M Motor t Remove gun assembly and inspect electrodes and leads. Improper position of electrode tips Bad buss bar connection Retension and realign. Cracked or chipped insulators Replace electrode. Cracked or burned lead insulators Replace electrode leads. Low line voltage Check voltage at power source. Correct cause of voltage drop or call the power company. Connect ignition g leads to the t transformer. f Start St t burner b and d obb Burned out transformer windserve spark. Check line voltage ings. to transformer primary. Motor does not come up to p p out on overload. speed and trips T Turn off ff power and d rotate t t blower bl wheel by hand to check for binding or excessive drag drag. Clean electrode Cl l t d titips and d resett the gap to 5/32 inches and correctly position tips. Replace the transformer. No spark or weak spark Properly ground the transformer case. Low line voltage Check voltage at power source. Correct cause of voltage drop or the call power company. Pump or blower overloading motor Correct cause of overloading. Faulty motor Replace motor. Page 35 Burner starts and fires, but locks out on safety. Source Procedure If burner continues to ti t run, this may be due to poor fire. Inspect fire. Poor Fire Flame Detector After burner fires, immediately jumper across flame detector terminals at the primary control. control Correction Unbalanced fire Replace nozzle Too much air − −lean short fire Reduce combustion air − check combustion. Too little air − − long dirty fire Increase combustion air − check combustion. Excessive draft Adjust barometric damper for correct draft. Too little draft or restriction Correct draft or remove restriction. Dirty cad cell face If fire is good, Faulty cad cell − exceeds 1500 fault is in the flame detector. hms Ch k detecCheck d t Loose or defective cad cell tor circuit. wires If burner locks out on safety, fault is in the primary control. Primary Control Causes Primary control circuit defective Clean cad cell face. Replace cad cell. Secure connections or replace cad cell holder and wire leads. Replace primary control. Burner starts and fires, but loses flame and locks out on safety. Source Procedure If burner continues to run (d l k (does nott lock out of safety), fault may be due to poor fire. Inspect p fi fire. Poor Fire Flame Detector Oil Supply After burner fires, immediately jumper across flame detector terminals at the primary control. Causes Unbalanced fire Replace nozzle Too much air − − lean short fire Reduce combustion air − check combustion. Too little air − − long dirty fire Increase combustion air − check combustion. Excessive draft Adjust barometric damper for correct draft. Too little draft or restriction Correct draft or remove restriction. Dirty CAD cell face If fire is good, Faulty CAD cell − − exceeds fault is in the flame detector. 15000 hms Ch k detecd t Check Loose or defective cad cell tor circuit. wires If burner loses flame (does not lock out on safety), fault is in the fuel syssys tem. Listen for pump whine Correction Clean CAD cell face. Replace CAD cell. Secure connections or replace cad cell holder and wire leads. Pump loses prime − air slug Prime pump at bleed port Pump loses prime − air leak in supply line Check supply line for loose connections and tighten fittings. Water slug in line Check oil tank for water (over 1 inch) pump or drain out water. Partially plugged nozzle or nozzle strainer Replace nozzle. Restriction in oil line Clear restriction. Plugged fuel pump strainer Clean strainer or replace pump. Cold oil − outdoor tank Change to number 1 oil. Page 36 Burner starts and fires, but short cycles (too little heat). Source Thermostat Limit Control Power Procedure Causes Check thermostat. Correction Heat anticipator set too low Correct heat anticipator setting. Vibration at thermostat Correct source of vibration. Thermostat in the path of a warm air draft Shield thermostat from draft or relocate. Dirty furnace air filters Clean or replace filter. Burner running too slow Increase blower speed to maintain proper temp. rise. Blower motor seized or burned out Replace motor. Connect voltmeter between line Blower bearings seized voltage lt connections ti tto primary i Blower wheel dirty control (black & white leads). If burner cycles due to power inter- Blower wheel in backward ruption it is cycling on limit. ruption, limit Wrong motor rotation Replace bearings and shaft. Clean blower wheel. Reverse blower wheel. Replace with properly rotating wheel. Restrictions in return or supply air system Correct cause of restriction. Adjustable limit control set too low Reset limit to maximum stop setting. If voltage fluctuates, fault is in the Loose wiring connection power source source. Recheck voltage Low or fluctuating line voltage at the power source. Locate and secure connection. Call power company. Burner runs continuously (too much heat). Source Procedure Thermostat Disconnect sco ect thermostat wires at the primary control. Primary control If burner turns off, fault is in the thermostat circuit. Causes Correction Shorted or welded thermostat contacts Repair or replace the thermostat. Stuck thermostat bimetal Clear obstruction or replace thermostat. Thermostat not level Level thermostat. Shorted thermostat wires Repair short or replace wires. Thermostat out of calibration Replace thermostat. Thermostat in cold draft Correct draft or relocate the thermostat. If burner does not turn off, fault is in the Defective primary control primary control. Page 37 Replace the defective primary control. Burner runs continuously cont. Source Procedure Causes Low CO2 less than 10%. Correction Too much combustion air Reduce combustion air. Air leaks into heat exchanger around inspection door, etc. Correct cause of air leak. Excessive draft Adjust barometric draft control for correct draft. Incorrect burner head adjustment Correct burner head setting. Dirty or plugged heat exchanger Combustion Check burner combustion for tem CO2, stack temperature, and smoke High Hi h smoke k reading more than a trace. High stack temtem perature is more than 550F Net. Clean heat exchanger. Readjust burner. Insufficient draft Increase draft. Incorrect burner head adjustment Correct burner setting. Too little combustion air Increase combustion air. Too little blower air Increase blower speed to maintain proper temp. rise. Blower belt too loose (if equipped) Tighten blower belt. Dirty or plugged heat exchanger Clean heat exchanger. Dirty blower wheel Clean blower wheel. Dirty furnace air filters Clean or replace filter. Restricted or closed registers or Readjust registers or dampdampers ers. Inspect fire and check oil pressure. Oil Pressure Partially plugged or defective nozzle Replace nozzle. Oil pressure is too low: less than 100 psi. Increase oil pressure top 100psi. Troubelshooting O23 / OHR23 / OF23 −5 Units Procedure Status Correction CONDITION 1: BURNER DOES NOT ENERGIZE WITH A CALL FOR HEAT. 1.1 Check limit switch contacts are closed and clean. Clean contacts. Replace limit switch if necessary. 1.2 Check for line votage at oil primary control. Voltage should be 120V Check primary voltage source. Take appropiate measures to correct if necessary. 1.3 Check LED light with burner off, no call for heat (no flame) 1.4 Sheild cad cell from external light 1.5 On warm air systems, Remove one thermostat lead and jumper thermostat (T to T) terminals on burner control. LED is on Cad cell or control is bad. Control sees external light or connections are shorted. See step 1.4. LED is off See step 1.5. LED is off Eliminate exteranl light or shield light from cad cell LED stays on Replace cad cell and recheck. If LED stays on remove cad cell lead wires from burner control and recheck. If LED turns off, replace cad cell bracket assembly. If LED stays on replace buner control Burner energizes Trouble in thermostat or limit circuit. Check thermostat or limit wiring connections. Burner does not energize Disconnect line voltage power and open line switch Check all wiring and tighten any loose connections. Recheck If burner does not energize replace burner control Page 38 Troubelshooting O23 / OHR23 / OF23 −5 Units Cont. CONDITION 2: BURNER STARTS, THEN LOCKS OUT ON SAFETY WITH LED FLASHING 1/2 SECOND ON 1/2 SECOND OFF 2.1 Check limit switch contacts are closed and clean. Clean contacts. Replace limit switch if necessary. 2.2 Check for line votage at oil primary control. Voltage should be 120V Check primary voltage source. Take appropiate measures to correct if necessary. 2.3 Check LED light with burner off, no call for heat (no flame) 2.4 Sheild cad cell from external light 2.5 On warm air systems, Remove one thermostat lead and jumper thermostat (T to T) terminals on burner control. 2.6 2 6 Hit reset button on burner con control LED is on Cad cell or control is bad. Control sees external light or connections are shorted. See step 2.4. LED is off See step 2.5. LED is off Eliminate exteranl light or shield light from cad cell LED stays on Replace cad cell and recheck. If LED stays on remove cad cell lead wires from burner control and recheck. If LED turns off, replace cad cell bracket assembly. If LED stays on replace buner control Burner energizes Trouble in thermostat or limit circuit. Check thermostat or limit wiring connections. Burner does not energize Disconnect line voltage power and open line switch Check all wiring and tighten any loose connections. Recheck If burner does not energize replace burner control LED stops flashing See step 2.7. LED continuse to flash Verify burner control is not in restricted mode. (1/2 second flash) Ignition is off Ignitor could be bad. bad Check line voltage at ignitor terminals. terminals If line voltage is present present, replace burner control 2.7 Listen for spark after burner energizes (after 2 second delay) Ignition is on 2.8 Check LED after flame is established, but before buner control lockcs out. LED is on until the burner control locks out and starts flashing during lock out. Replace burner control Burner locks out See step 2.10 Burner continuse to run System is O.K OK LED is on. Go back to step 2.6 LED is off off. See step 2 2.11 11 LED is on. Replace cad cell assembly. LED is off off. Replace burner control. control 2.9 Check cad cell sighting for view of flame Disconnect line voltage and open line switch Unplug cad cell and clean cad cell face with soft cloth. Check sighting for clear view of flame. Place cad cell back in socket. Reconnect line voltage and close line switch. Start burner 2.10 Check cad cell. Disconnect line voltage and open line switch Replace cad cell with new cad cell Disconnect all wires from thermostat to prevent a call for herat. Reconnect line voltage and close line switch. Expose new cad cell to bright light, such as a flash light 2.11 Check cad cell bracket assembly. Disconnect line voltage and open line switch Remove cad cell wires from quick connect connectors on the burner control and leave wires open. Apply power to buner control. Place jumper across cad cell terminals after buner motor is energized. Wait for 15 second pre−purge to complete. Check oil valve, oil valve Ignition is on but no oil is sprayed to combustion cham- wiring, pump and oil supply. ber Page 39
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