1. Manuals
  2. Brands
  3. Lennox Manuals
  4. Furnace
  5. G32 SERIES
  6. Unit information

Lennox G32 SERIES Unit Information

Hide thumbs Also See for G32 SERIES:
Table of Contents

Advertisement

Quick Links

See also: User's Information Manual
Service Literature
G32 series units are high−efficiency upflow gas furnaces
manufactured with DuralokPlust aluminized steel clam
shell type heat exchangers. G32 units are available in
heating capacities of 75,000 to 125,000 Btuh and cooling
applications up to 5 tons. Refer to Engineering Handbook
for proper sizing.
Units are factory equipped for use with natural gas only. LP
kits are available. All G32−1 through −4 model units feature
the Lennox SureLightT silicon nitride ignition system. G32−5
and later model units feature the SureLight two stage inte
grated control board. The G32 units meet the California Nitro
gen Oxides (NO
) Standards and California Seasonal Effi
x
ciency requirements without modification. All units use a two−
stage gas valve along with a two−stage combustion air blow
er. The gas valve is redundant to assure safety shut−off as re
quired by A.G.A. or C.G.A.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are
subject to change. Procedures outlined in this manual are
presented as a recommendation only and do not super
sede or replace local or state codes. In the absence of local
or state codes, the guidelines and procedures outlined in
this manual (except where noted) are recommended only.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person
al injury or loss of life. Installation and service must
be performed by a qualified installer or service
agency.
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 discon
nect switch(es). Unit may have multiple
power supplies.
G32 SERIES UNITS
Page 1

TABLE OF CONTENTS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 1998 Lennox Industries Inc.
G32
Corp. 9729−L12
revised 03−2003
1
2
3
4
4
6
18
26
. . . . . . . . . . . . . .
27
29
30
. . . . .
34
. . . . .
51
Litho U.S.A.

Advertisement

Table of Contents
loading

Related Manuals for Lennox G32 SERIES

Summary of Contents for Lennox G32 SERIES

  • Page 1: Table Of Contents

    Corp. 9729−L12 revised 03−2003 Service Literature G32 SERIES UNITS G32 series units are high−efficiency upflow gas furnaces manufactured with DuralokPlust aluminized steel clam shell type heat exchangers. G32 units are available in heating capacities of 75,000 to 125,000 Btuh and cooling applications up to 5 tons.

  • Page 2: Specifications

    SPECIFICATIONS Model No. G32Q3−75 G32Q3/4−100 G32Q4/5−100 G32Q4/5−125 Input Btuh (kW) − High 75,000 (22.0) 100,000 (29.3) 125,000 (36.6) Input Btuh (kW) − Low 51,000 (15.0) 68,000 (19.9) 85,000 (24.9) Output Btuh (kW) − High 68,850 (20.2) 93,200 (27.3) 92,400 (27.1) 116,375 (34.1) Output Btuh (kW) −...
  • Page 3 BLOWER/WATTS DATA G32Q3−75 BLOWER PERFORMANCE Air Volume and Motor Watts at Specific Blower Taps External Static External Static Pressure High Medium−High Medium−Low in. w.g. Watts Watts Watts Watts 1490 1340 1060 1435 1305 1050 1385 1260 1025 1330 1215 1000 1260 1160 1200...

  • Page 4: Blower Data

    BLOWER DATA FILTER AIR RESISTANCE cfm (L/s) in. w.g. (Pa) 0 (0) 0.00 (0) 200 (95) 0.01 (0) 400 (190) 0.03 (5) 600 (285) 0.04 (10) 800 (380) 0.06 (15) 1000 (470) 0.09 (20) 1200 (565) 0.12 (30) 1400 (660) 0.15 (35) 1600 (755) 0.19 (45)
  • Page 5 G32 PARTS ARRANGEMENT GLASS FIBER GASKET FLUE COLLAR FRESH AIR TOP CAP INTAKE FITTING WARM HEADER (COLLECTOR) BURNER BOX ASSEMBLY CABINET PATCH PLATE WITH BARBED FITTING PATCH AND FLAME ROLL−OUT SWITCH PLATE FLUE DuralokPlus TRANSITION HEAT EXCHANGER ASSEMBLY LOW HEAT DIFFERENTIAL PRESSURE FLAME SIGHT...

  • Page 6: I Unit Components

    MAKE UP BOX INSTALLATION OUTSIDE INSTALLATION Box may be installed inside or outside cabinet and INSIDE INSTALLATION may be installed on left side or right side of cabinet MAKE UP BOX STAR WASHERS MAKE UP BOX MUST BREAK PAINT ON UNIT CABINET FOR PROPER GROUND.

  • Page 7: Flame Sensor

    Each orifice and burner are sized specifically to the 2. Circuit Breaker (CB8) unit. Refer to Lennox Repair Parts Listing for correct sizing A 24V circuit breaker is also located in the control box. The information. A flame retention ring in the end of each burner...

  • Page 8: Diagnostic Codes

    SURELIGHT CONTROL BOARD TABLE 1 SURELIGHT CONTROL TERMINAL DESIGNATIONS ACB COOL Blower − Cooling Speed (Line Volt) ACB HEAT Blower − Heating Speed (Line Volt) PARK Alternate Blower Speeds (Dead) ACB LOW Continuous Low Speed Blower Accessory Terminal (Line Volt) 120VAC Hot to Transformer 120VAC Hot Input HTG ACC...
  • Page 9 TABLE 3 a−Electronic Ignition Figures 11 and 12 On a call for heat the SureLight control monitors the com SureLight BOARD J156 TERMINAL bustion air blower pressure switch. The control will not be DESIGNATIONS gin the heating cycle if the pressure switch is closed (by− passed).
  • Page 10 SureLight Control Ignition Sequence Board 56L83, 24L85, 63K89 5 SEC É É Pre −Purge Ignitor Warmup Trial for Blower On" Post É É É É Ignition Delay Purge É É É É É É É É É É É É É É É É É É É É É É É É É É É...
  • Page 11 While in the single−stage thermostat mode (single jumper setting), the burners will always fire on first−stage heat. The All G32−5 units units are equipped with the Lennox two− combustion air inducer will operate on low speed and in stage integrated SureLight control board. The system door blower will operate on low heat speed.
  • Page 12 TABLE 5 TWO−STAGE INTEGRATED CONTROL BOARD Heating Fan Off Delay Delay (Seconds) Switch 1 Switch 2 LEDs SWITCHES 1 − 4 Switch 3 − Second Stage Delay (Used with Single−Stage Thermostat Only) −− This switch is used to determine the second stage on delay when a single−stage thermostat is SENSOR being used.
  • Page 13 TABLE 7 TABLE 8 Integrated Control Board Terminals Integrated Control Board 5 Pin Terminal 120VAC Neutral PIN # Function Ignitor LINE Line Combustion Air Inducer High Speed XFMR Transformer Combustion Air Inducer Low Speed Electronic Air Cleaner Combustion Air Inducer Neutral CIRC Indoor Blower Ignitor Neutral...
  • Page 14 TABLE 10 DIAGNOSTIC CODES Diagnostic LEDs are labeled DS1 and DS2. See figure 14 for location of diagnostic LEDs. DESCRIPTION Power on − Normal operation. SIMULTANEOUS SIMULTANEOUS Also signaled during cooling and continuous fan. SLOW FLASH SLOW FLASH SIMULTANEOUS SIMULTANEOUS Normal operation −...

  • Page 15: Gas Valve

    100% Sealed Combustion LIMIT CONTROL (S10) FOR The burner box is completely sealed and operates under a G32 SERIES UNITS AND ALTERNATE STYLE Units may be equipped with either style limit. negative pressure. A pressure hose is connected from the burner box to the gas valve regulator and differential pres sure switch.
  • Page 16 (Combustion Air Prove Switch) (.20" W.C. shown) required to obtain unit operation. If the All G32 series units are equipped with a differential pressure switch does not successfully sense the required differen switch S102 located on the vestibule panel.The G32−75 unit tial, the switch cannot close and the furnace cannot oper only, is equipped with a second pressure switch S128.
  • Page 17 CHART REPESENTS NORMAL OPERATING CHARACTERISTICS OF THE PRESSURE SWITCH ONLY AND SHOULD NOT BE USED FOR TROUBLSHOOTING −1.2 DIFFERENTIAL SWITCH CLOSED −1.0 −0.8 −0.6 DIFFERENTIAL SWITCH OPEN (Furnace will not operate) −0.4 −0.2 −0.2 −0.4 −0.6 −0.8 −1.0 −1.2 BURNER BOX STATIC PRESSURE FIGURE 19 Temporarily jumpering the pressure switch when trouble TEE AND 1/4"i.d.

  • Page 18: Placement And Installation

    air blower side of the switch. 7 − Immediately after applying last coat of cement to pipe, Example − one side of the pressure switch reads .60" and while both inside socket surface and end of pipe and the other side of the pressure switch reads .10". are wet with cement, forcefully insert end of pipe into Pressure differential is .60"...
  • Page 19 Intake Piping 2 − Visually inspect the venting system for proper size and horizontal pitch and determine there is no blockage or 1 − Cement intake piping in slip connector located at top of restriction, leakage, corrosion and other deficiencies unit.
  • Page 20 Heating cable installation kit is avail together as possible at termination end (refer to il lustrations). Maximum separation is 3" (76mm) on able from Lennox. See Condensate Piping section for part roof terminations and 6" (152mm) on side wall ter numbers.
  • Page 21 1/2 (12.7) FOAM INSULATION EXHAUST IN UNCONDITIONED SPACE Inches(mm) TERMINATION EXHAUST OUTSIDE WALL INTAKE TERMINATION Optional Turndown 12 (305) Min. INTAKE Shown above grade. (Intake Only) TOP VIEW WALL TERMINATION Inches (22G44) LB−49107CD for 2 (50.8) Venting (mm) CONCENTRIC WALL TERMINATION (44J40) LB−65701A for 3 (76.2) Venting (60G77) LB−49107CE for G32−75 Units Only FIGURE 23...
  • Page 22 When horizontally vented, minimum clearance for ter METAL OR PLASTIC mination from electric meters, gas meters, regulators STRAPPING OR LARGE and relief equipment is 4 ft. (1.2m) for US installations. WIRE TIES Refer to the current CAN/CGA−B149.1 and .2 for installations in Canada or with authorities having local jurisdiction.
  • Page 23 EXHAUST Front View (229) (127) VENT Front View EXHAUST VENT (305) NOTE−Enclosed exhaust 5−1/2 INTAKE VENT pipe is insulated with 1/2" (140) INTAKE (13mm) foam insulation. VENT If intake and exhaust pipes are reversed, slit (864) 18 MAX. and remove foam insula (457) tion and reapply to other vent.
  • Page 24 Heating Install the nipple/adapter assembly from the outside cable kit is available from Lennox in various lengths; of the cabinet and insert the adapter into the threaded 6ft. (1.8m) − kit no. 18K48; 24ft. (7.3m) − kit no. 18K49;...
  • Page 25 G32 CONDENSATE REMOVAL PROCESSB Condensate Removal Process: 1. Condensate mixed with flue products exits DETAIL OF the coil and enters the cold header box. FLUE TRAPB 2. Condensate and flue products are separated. Flue products are drawn into the combustion air blower while condensate is drained into the COLD header box condensate trap.

  • Page 26: Start Up

    III−START UP How To Operate Gas Valve (Figure 37) A−Preliminary and Seasonal Checks WARNING 1 − Inspect electrical wiring, both field and factory installed for loose connections. Tighten as required. If you do not follow these instructions exactly, a 2 − Check voltage at disconnect switch. Voltage must be fire or explosion may result causing property within range listed on the nameplate.

  • Page 27: Heating System Service Checks

    Use of a specialty Gas Leak Detector is strongly recommended. It is available 75,000 7.5%−9.2% 5.5%−6.9% through Lennox under part number 31B2001. 100,000 8.0%−9.5% 5.2%−6.6% Do not use matches, candles, flame or any other source of 125,000 7.9%−9.4%...
  • Page 28 E−Testing Gas Supply Pressure MANIFOLD CHECK (G32−75 SHOWN) When testing supply gas pressure, connect test gauge to HOSE BARB inlet pressure tap (field provided). Check gas line pressure with unit firing at maximum rate or high fire. Low pressure may result in erratic operation or underfire. High pressure BURNER can result in permanent damage to gas valve or overfire.

  • Page 29: Typical Operating Pressures

    SureLight control. Use a flame signal transducer (part change blower speed taps see the Blower Speed Taps number 78H5401) available from Lennox to measure the section in this manual. flame signal, if meter used will not read microamp signal.

  • Page 30: Maintenance

    G32 BLOWER REMOVAL To Remove Blower: 1. Turn off line voltage power. Unplug J69 from P69 located on blower deck. 2. Disconnect thermostat wiring connec tions by removing low voltage terminal strip. 3. Disconnect J58/P58 located on blower deck. 4. Disconnect J43/P43 from blower motor. 5.
  • Page 31 Filter handicoater is RP Products coating no. 17− Remove 9 pin plug above the blower deck. 418 and is available as Lennox part no. P 8 5069. 18− Remove the limit switch and the pressure switch from 3 − If replacement is necessary, order Lennox part no.
  • Page 32 BURNER MOUNTING PATCH PLATE BRACKET Simplified Burner Removal: 1− Remove cover by loosening bot tom screws (2) and removing cover front screws (5). 2− Remove ignitor wire and sensor wire. Remove gas valve and manifold assembly. 3− Remove burner assembly. BARBED PRESSURE PATCH PLATE UNIT VEST PANEL...
  • Page 33 14− Re install ignitor and sensor bracket assemblies on 21− Re−install the sensor wire to the spade connector on burners. the SureLight control. Re install the 2 pin ignitor plug at the burner box. NOTE − Ignitor must be installed on the opposite side of the burner from the metal button protrusions.

  • Page 34: Wiring Diagrams And Operating Sequence

    VII−WIRING DIAGRAMS & SEQUENCE OF OPERATION TYPICAL G32 FIELD WIRING DIAGRAM FLAME IGNITION ROLLOUT FURNACE MAY BE CONTROLLED BY EITHER LIMIT CONTROL SWITCH A SINGLE OR TWO STAGE THERMOSTAT (TWO STAGE THERMOSTAT SHOWN) LOW HEAT HIGH HEAT FIELD PRESSURE PRESSURE MAKE−UP SWITCH SWITCH...
  • Page 35 G32−2 UNIT DIAGRAM Page 35...
  • Page 36 G32−3 UNIT DIAGRAM Page 36...
  • Page 37 Sequence of Operation G32−2, −3 Two−stage Mode, Single−stage Thermostat 1 − SureLight control energizes combustion air blower B6 Ignitor operation will vary between SureLight boards. on low speed. Combustion air blower runs until com Boards 24L85, 56L83 and 63K89, will energize ignitor for bustion air blower switch S102(or S128 onG32−75 the first second of the 4 second ignition trial.

  • Page 38: Heating Sequence Of Operation

    G32−2 &−3 HEATING SEQUENCE OF OPERATION NORMAL HEATING MODE ABNORMAL HEATING MODE GAS VALVE OFF. COMBUSTION AIR INDUCER ON. POWER ON INDOOR BLOWER ON. LED #1 AND #2 ALTERNATING FAST FLASH. CHECK FOR BROKEN IGNITOR OR OPEN IGNITOR CIRCUIT. CONTROL SELF−CHECK OKAY? GAS VALVE OFF.
  • Page 39 HEATING SEQUENCE CONTINUED NORMAL HEATING MODE ABNORMAL HEATING MODE PREPURGE 15 SECONDS IGNITION SEQUENCE BEGINS (Ignition trial counter initiated.) WATCHGUARD 60 MINUTE DELAY: FLAME IGNITOR WARM−UP FAILURE. GAS VALVE OFF. COMBUSTION (20 SECONDS) AIR INDUCER OFF. INDOOR BLOWER OFF. LED #1 & LED #2 ALTERNATE SLOW FLASH. TWO−STAGE MODE W2 TIMED MODE SINGLE−STAGE MODE...
  • Page 40 HEATING SEQUENCE CONTINUED NORMAL HEATING MODE ABNORMAL HEATING MODE PREPURGE (See top of previous page.) PRESSURE SWITCH CLOSED? GAS VALVE DE−ENERGIZED. INDOOR BLOWER DE−ENERGIZED. TWO−STAGE MODE W2 TIMED MODE COMBUSTION AIR INDUCER ON FOR 2.5 MINUTES. CALL FOR 1st STAGE HEAT SINGLE STAGE T’STAT PRESSURE SWITCH CALL FOR 2nd STAGE...
  • Page 41 COOLING SEQUENCE OF OPERATION NORMAL COOLING MODE ABNORMAL COOLING MODE POWER ON IGNITION CONTROL MAIN POWER ON. GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER OFF WITH NORMAL DELAY. CONTROL SELF DIAGNOSTIC CHECK. SIGNAL CIRCUIT BOARD FAILURE AT LED. IS CONTROL OPERATING NORMALLY? INTERRUPT MAIN POWER TO RESET CONTROL.
  • Page 42 CONTINUOUS LOW SPEED FAN SEQUENCE OF OPERATION LED: SLOW FLASH RATE REMAINS UNCHANGED THROUGHOUT SEQUENCE. MANUAL FAN SELECTION MADE AT THERMOSTAT. CONTROL (G) ENERGIZES SYSTEM FAN AT ACB LOW SPEED. ACC. TERMINAL IS ENERGIZED. HTG ACC. TERM. ENERGIZES THERMOSTAT CALLS FOR HEAT (W). WITH COMB.
  • Page 43 TYPICAL G32−5, −6 SCHEMATIC WIRING DIAGRAM Page 43...
  • Page 44 Sequence of Operation G32−5, −6 Single−Stage Thermostat, Two Stage Heat. Jumper E20 set at SINGLE" Sequence depends on type thermostat used. Units are 1− SureLight control energizes combustion air inducer B6 applicable for single stage or two stage thermostats. on low heat speed. Combustion air inducer runs until Both type thermostats are described below.
  • Page 45 G32−5 & −6 HEATING SEQUENCE OF OPERATION NORMAL AND ABNORMAL HEATING MODE GAS VALVE OFF. COMBUSTION AIR INDUCER POWER ON OFF. INDOOR BLOWER OFF. CHECK FOR BROKEN IGNITOR OR OPEN IGNITER CIRCUIT. DS1 AND DS2 ALTERNATING FAST FLASH. CONTROL SELF−CHECK OKAY? GAS VALVE OFF.
  • Page 46 HEATING SEQUENCE OF OPERATION CONTINUED THERMOSTAT CALLS FOR HEAT DS1 AND DS2 SIMULTANEOUS FAST FLASH (Refer to box A on previous page) FIRST−STAGE (LOW FIRE) PRESSURE GAS VALVE OFF. COMBUSTION AIR INDUCER SWITCH CLOSED WITHIN 2.5 MINUTES? OFF. INDOOR BLOWER OFF. UNIT WILL RETRY AFTER 5−MINUTE WAIT PERIOD.
  • Page 47 HEATING SEQUENCE OF OPERATION CONTINUED THERMOSTAT CALLS FOR HEAT. DS1 AND DS2 SIMULTANEOUS FAST FLASH. SEE BOX A. FLAME SIGNAL ABOVE (u0.17 microamps) LOW FLAME SIGNAL (Does not affect control operation) DS1 SLOW FLASH, DS2 FAST FLASH. SINGLE−STAGE THERMOSTAT MODE TWO STAGE THERMOSTAT MODE (E20 SET AT SINGLE") (E20 SET AT TWO")
  • Page 48 HEATING SEQUENCE OF OPERATION CONTINUED SEE BOX A NORMAL OPERATION DS1 AND DS2 SIMULTANEOUS SLOW FLASH. SEE BOX B THERMOSTAT CALLS FOR HEAT DS 1 AND DS 2 SIMULTANEOUS FAST FLASH GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER ON. IS PRIMARY LIMIT AND ROLLOUT DS1 SLOW FLASH, DS2 ON.
  • Page 49 COOLING SEQUENCE OF OPERATION POWER ON IS POLARITY REVERSED? SIGNAL POLARITY REVERSED. DS1 FAST FLASH, DS2 SLOW FLASH. SIGNAL IMPROPER GROUND AT DS. IS THERE IS VOLTAGE LOW VOLTAGE SIGNAL AT DS HOLDS SIGNAL HOLDS PROPER GROUND? ABOVE 75 VOLTS? UNTIL VOLTAGE RISES ABOVE 75 VOLTS.
  • Page 50 CONTINUOUS LOW SPEED FAN SEQUENCE OF OPERATION MANUAL FAN SELECTION MADE AT THERMOSTAT. AFTER 2 SECOND DELAY, INDOOR BLOWER IS ENERGIZED ON CONTINUOUS FAN SPEED (LOW HEAT / LOW COOL). THERMOSTAT CALLS FOR FIRST STAGE COOL. THERMOSTAT CALLS FOR FIRST−STAGE HEAT. COMPRESSOR IS ENERGIZED AND INDOOR BURNERS IGNITE AND INDOOR BLOWER BLOWER CONTINUES TO OPERATE IN LOW...

  • Page 51: Troubleshooting Guide Surelight Control

    VIII− Troubleshooting Guide SureLight Control UPON INITIAL POWER UP, REMOVE ALL THERMOSTAT DEMANDS TO THE UNIT Unless otherwise noted, condition applies to all G32 units. PROBLEM: 1 UNIT FAILS TO OPERATE IN THE COOLING, HEATING, OR CONTINUOUS FAN MODE Condition Possible Cause Corrective Action / Comments 1.1.1...
  • Page 52 PROBLEM 1: UNIT FAILS TO OPERATE IN THE COOLING, HEATING, OR CONTINUOUS FAN MODE Condition Possible Cause Corrective Action / Comments ACTION 1 − Check that the unit is properly 1.5.1 grounded. − On initial power−up the combustion ACTION 2 − Install a proper main ground to the Improper ground to the unit.
  • Page 53 PROBLEM 3: UNIT FAILS TO FIRE IN THE HEATING MODE, COMBUSTION AIR BLOWER DOES NOT ENERGIZE (CONT.). Condition Possible Cause Corrective Action/Comments − Unit operates with a cooling and con 3.3.1 ACTION 1 − Check for correct wiring and loose tinuous fan demand.
  • Page 54 PROBLEM 5: UNIT FAILS TO FIRE IN THE HEATING MODE, COMBUSTION AIR BLOWER ENERGIZES, IGNITOR IS ENERGIZED. (CONT.) Condition Possible Cause Corrective Action/Comments ACTION 1 − Check line pressure at the gas valve. 5.1.1 Pressure should not exceed 13" WC for both nat −...
  • Page 55 LED#2−On bustion air blower. changer to proper Lennox personnel. ACTION 1 − Check for sooting deposits or other restrictions in the heat exchanger assembly. Clean assembly as outlined in instruction manu 6.3.4...
  • Page 56 PROBLEM 6: BURNERS LIGHT WITH HEATING DEMAND BUT UNIT SHUTS DOWN PREMATURELY (CONT.) − Combustion air blower energizes with a heating demand. − Burners light. − Diagnostic lights flash watch guard ACTION 1 − Check that the sensor is properly lo 6.5.1 flame failure.

Table of Contents