Lennox 97G2UHV Installation Instructions Manual
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Lennox 97G2UHV Installation Instructions Manual

Lennox 97G2UHV Installation Instructions Manual

Warm air gas furnace upflow/ horizontal left/right air discharge direct vent & non-direct vent
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INSTALLATION INSTRUCTIONS
97G2UHV
This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to
the potential for personal injury or death.
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 licensed professional installer (or
equivalent), service agency or the gas supplier.
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
Manufactured By
Allied Air Enterprises LLC
A Lennox International, Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
508404-01
This manual must be left with the homeowner for future reference.
WARNING
CAUTION
Warm Air Gas Furnace Upflow/
Horizontal Left/Right Air Discharge
Direct Vent & Non-Direct Vent

Table of Contents

Unit Dimensions ..........................................................2
Parts Arrangement.......................................................3
Gas Furnace ................................................................4
Shipping and Packing List ...........................................4
Safety Information .......................................................4
General ........................................................................6
Installation .................................................................10
Filters .........................................................................13
Duct System ..............................................................14
Venting Practices .......................................................15
Condensate Piping ....................................................34
Gas Piping .................................................................37
Electrical ....................................................................40
Blower Performance ..................................................50
Unit Start-Up ..............................................................54
Other Unit Adjustments..............................................56
Service.......................................................................57
Repair Parts List ........................................................59
*P508404-01*
Issue 2332
(P) 508404-01
Page 1 of 60

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Summary of Contents for Lennox 97G2UHV

  • Page 1: Table Of Contents

    Be Repair Parts List ............59 careful when you handle this equipment. Manufactured By *P508404-01* Allied Air Enterprises LLC A Lennox International, Inc. Company 215 Metropolitan Drive (P) 508404-01 West Columbia, SC 29170 508404-01 Issue 2332...

  • Page 2: Unit Dimensions

    Unit Dimensions 1 NOTE - C*20 and D*20 (5 Ton) size units installed in upflow TOP VIEW applications that require air volumes of 1800 cfm (850 L/s) or greater must have one of the following: 24-7/8 1. Single side return air with transition, to accommodate 20 x 25 x 1 (63) 1-7/8 in.

  • Page 3: Parts Arrangement

    Parts Arrangement HEAT EXCHANGER ASSEMBLY BURNER BOX ASSEMBLY GAS VALVE AND MANIFOLD FLUE COLLAR COMBUSTION AIR INDUCER CABINET PRIMARY LIMIT BLOWER DECK ACCESS PANEL BLOWER ASSEMBLY CONTROL BOX Figure 1. 508404-01 Issue 2332 Page 3 of 60...

  • Page 4: Gas Furnace

    1 - Snap Plug 1 - Wire tie The 97G2UHV can be installed as either a Direct Vent or a Non-Direct Vent Gas Central Furnace. 1 - Condensate trap 1 - Condensate trap cap...
  • Page 5 Building Codes When installed, this furnace must be electrically grounded according to local codes. In addition, in the United States, In the USA, installation of gas furnaces must conform with installation must conform with the current National local building codes. In the absence of local codes, units Electric Code, ANSI/NFPA No.

  • Page 6: General

    Use of Furnace as a Construction Heater NOTWITHSTANDING THE FOREGOING, INSTALLER IS RESPONSIBLE FOR CONFIRMING THAT THE USE Units may be used for heating of buildings or structures OF CONSTRUCTION HEAT IS CONSISTENT WITH under construction, if the following conditions are met to THE POLICIES AND CODES OF ALL REGULATING ensure proper operation.
  • Page 7 Combustion, Dilution & Ventilation Air of ANSI on the referenced subject, which is represented only by the standard in its entirely. If this unit is installed as a Non-Direct Vent Furnace, follow the guidelines in this section. In Canada, refer to the CSA B149 Installation codes. NOTE: In Non-Direct Vent Installations, combustion air is taken from indoors and flue gases are discharged outdoors.
  • Page 8 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.
  • Page 9 Roof Terminated Exhaust Pipe Inlet Air Minimum 12 in. (305mm) Ventilation Furnace above Crawl Louvers (Crawl Space) Space Floor Coupling or *Intake Debris Screen Provided 3 in. to 2 in. Transition (Field Provided) * See Maximum Vent Lengths table Figure 8. Equipment in Confined Space - All Air from NOTE-The inlet and outlet air openings shall each have a Outside free area of at least one square inch per 4,000 Btu (645mm...

  • Page 10: Installation

    Allow for clearances to combustible materials as indicated Installation on the unit nameplate. Setting Equipment WARNING Do not connect the return air ducts to the back of the furnace. Doing so will adversely affect the operation of Left Side Right Side the safety control devices, which could result in personal injury or death.
  • Page 11 Return Air Guidelines Return air can be brought in through the bottom or either WARNING side of the furnace installed in an upflow application. If the furnace is installed on a platform with bottom return, make Improper installation of the furnace can result in an airtight seal between the bottom of the furnace and the personal injury or death.
  • Page 12 Horizontal Applications WARNING Do not install the furnace on its front or its back. See Figure 17. Figure 15. Side Return Air Figure 17. (with transition and filter) This furnace can be installed in horizontal applications with either right or left hand air discharge. Removing the Bottom Panel Remove the two screws that secure the bottom cap to the Refer to Figure 18 for clearances in horizontal applications.

  • Page 13: Filters

    Suspended Installation of Horizontal Unit Route auxiliary drain line so that water draining from this outlet will be easily noticed by the homeowner. This furnace may be installed in either an attic or a crawl space. Either suspend the furnace from roof rafters or floor If necessary, run the condensate line into a condensate joists, as shown in Figure 19, or install the furnace on a pump to meet drain line slope requirements.

  • Page 14: Duct System

    Duct System CAUTION Use industry approved standards to size and install the Solvent cements for plastic pipe are flammable liquids supply and return air duct system. This will result in a quiet and should be kept away from all sources of ignition. and low-static system that has uniform air distribution.

  • Page 15: Venting Practices

    IMPORTANT surface of fitting and male end of pipe to depth of fitting socket. 97G2UHV exhaust and intake connections are made of PVC. Use PVC primer and solvent cement when NOTE: Time is critical at this stage. Do not allow using PVC vent pipe.
  • Page 16 Exhaust Piping system has been installed improperly, you must correct the system as indicated in the general venting requirements In areas where piping penetrates joist or interior walls, section. hole must be large enough to allow clearance on all sides of pipe through center of hole using a hanger. When furnace is installed in a residence where unit WARNING is shut down for an extended period of time, such...
  • Page 17 Exhaust Piping Seal any unused openings in the common venting system. Route piping to outside of structure. Continue with installation following instructions given in piping termination Inspect the venting system for proper size and section. horizontal pitch. Determine that there is no blockage, restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.
  • Page 18 Use the following steps to correctly size vent pipe diameter. 045, 070, Furnace capacity? 090, 110, 135 btuh NOTE: All horizontal runs of exhaust pipe must slope back toward unit. A minimum of 1/4” (6 mm) drop for each 12” (305 mm) of horizontal run is mandatory for drainage.
  • Page 19 Maximum Allowable Intake or Exhaust Vent Length in Feet Standard Termination at Elevation 0 - 4,500 ft 1-1/2" Pipe 2" Pipe 2-1/2" Pipe 3" Pipe Number of 90° Capacity Capacity Capacity Capacity Elbows Used Standard Termination Elevation 4,501 - 10,000 ft 1-1/2"...
  • Page 20 Maximum Allowable Intake or Exhaust Vent Length in Feet Concentric Termination at Elevation 0 - 4,500 ft 1-1/2" Pipe 2" Pipe 2-1/2" Pipe 3" Pipe Number of 90° Capacity Capacity Capacity Capacity Elbows Used Concentric Termination Elevation 4,501 - 10,000 ft 1-1/2"...
  • Page 21 Maximum Allowable Exhaust Vent Lengths with Furnace Installed in a Closet or Basement Using Ventilated Attic or Crawl Space for Intake Air in Feet Standard Termination at Elevation 0 - 4,500 ft 1-1/2" Pipe 2" Pipe 2-1/2" Pipe 3" Pipe Number of 90°...
  • Page 22 TYPICAL EXHAUST PIPE CONNECTIONS IN UPFLOW DIRECT OR NON-DIRECT VENT APPLICATIONS Pipe size determined in Table 5 2” 2” 2” 2” 3” 2” TRANSITION EXHAUST *2” 045/070 Only 1-1/2” DO NOT transition from smaller to larger TRANSITION pipe in horizontal runs 2”...
  • Page 23 TYPICAL INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT OR NON-DIRECT VENT APPLICATIONS 2” 3” Pipe size determined in Table 5 TRANSITION INTAKE *2” 2” 2” 2” 2” * When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible. NOTE: Exhaust pipe and intake pipe must be the same diameter.
  • Page 24 The air intake piping must not terminate too close to the flooring or a platform. Ensure that the intake air Intake Debris inlet will not be obstructed by loose insulation or other Screen items that may clog the debris screen. (Provided) If intake air is drawn from a ventilated attic (Figure 31) or ventilated crawlspace (Figure 32) the exhaust...
  • Page 25 At vent termination, care must be taken to maintain protective coatings over building materials (prolonged exposure to exhaust condensate can destroy protective Roof Terminated Exhaust Pipe coatings). It is recommended that the exhaust outlet not be located within 6 feet (1.8 m) of a condensing unit because the condensate can damage the painted coating.
  • Page 26 Maximum Allowable Exhaust Vent Pipe Length (in ft.) without Insulation in Unconditioned Space for Winter Design Temperatures Unit Input Size Vent Pipe Winter Design Temperatures1 ºF (ºC) Diameter 1-1/2 in. 32 to 21 2 in. (0 to -6) 2-1/2 in. 3 in.
  • Page 27 VENT TERMINATION CLEARANCES FOR NON-DIRECT VENT INSTALLATIONS IN THE US AND CANADA INSIDE CORNER DETAIL Fixed Operable Fixed Closed Closed Operable AREA WHERE TERMINAL AIR SUPPLY INLET VENT TERMINAL IS NOT PERMITTED US Installations Canadian Installations Clearance above grade, veranda, 12 inches (305mm) or 12 inches (305mm) 12 inches (305mm) or 12 inches (305mm) porch, deck or balcony...
  • Page 28 VENT TERMINATION CLEARANCES FOR DIRECT VENT INSTALLATIONS IN THE USA AND CANADA INSIDE CORNER DETAIL Fixed Operable Fixed Closed Closed Operable AREA WHERE TERMINAL AIR SUPPLY INLET VENT TERMINAL IS NOT PERMITTED US Installations Canadian Installations Clearance above grade, veranda, 12 inches (305mm) or 12 inches (305mm) 12 inches (305mm) or 12 inches (305mm) porch, deck or balcony...
  • Page 29 Details of Intake and Exhaust Piping Terminations for Direct Vent Installations NOTE: In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged to outdoors. NOTE: Flue gas may be slightly acidic and may adversely affect some building materials. If any vent termination is used and the flue gasses may impinge on the building Inlet Air Minimum 12 in.
  • Page 30 If intake and exhaust piping must be run up a side FIELD-PROVIDED 1-1/2” (38mm) accelerator wall to position above snow accumulation or other REDUCER MAY BE REQUIRED provided on 71M80 & 44W92 TO ADAPT DIFFERENT VENT kits for -045 and -070 models obstructions, piping must be supported every 24”...
  • Page 31 FIELD FABRICATED WALL TERMINATION NOTE − FIELD−PROVIDED REDUCER MAY BE 2” (51mm) 3” (76mm) REQUIRED TO ADAPT LARGER VENT PIPE SIZE Vent Pipe Vent Pipe TO TERMINATION A− Minimum clearance above grade or average 12” (305 mm) 12” (305 mm) snow accumulation B−...
  • Page 32 Details of Exhaust Piping Terminations for Non- Direct Vent Applications Exhaust pipes may be routed either horizontally through an outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof SIZE TERMINATION is preferred. Figure 45 through Figure 48 show typical PER EXHAUST PIPE terminations.
  • Page 33 Exhaust through Crawl Space Vent Option All 33” condensing gas furnaces (92%+) are now approved Exhaust from Furnace to be vented down through a crawl space. Ensure a vent To Termination pipe drain kit, 51W18 (USA) or 15Z70 (Canada), is used as directed through the floor joists and into the crawl space.

  • Page 34: Condensate Piping

    Figure 54 and Figure 55 show the furnace and Condensate Piping evaporator coil using a separate drain. If necessary the condensate line from the furnace and evaporator This unit is designed for either right or left side exit of coil can drain together. See Figure 56 and Figure 57. condensate piping in upflow applications.
  • Page 35 (Unit shown in horizontal left-hand discharge position) Field Provided Vent Evaporator (4” min. to 5” max. above Coil condensate drain connection) 4”min 5”max 5’ max. PVC Pipe Only Condensate Drain Connection (Trap at coil is optional) Drain Pan Piping from furnace and evaporator coil must slope down a minimum 1/4” per ft. toward trap Figure 54.
  • Page 36 Figure 58. Trap / Drain Assembly Using 1/2” PVC or 3/4” PVC Page 36 of 60 Issue 2332 508404-01...

  • Page 37: Gas Piping

    IMPORTANT IMPORTANT When combining the furnace and evaporator coil A low inlet pressure switch in LP/propane applications drains together, the A/C condensate drain outlet must is recommended. be vented to relieve pressure in order for the furnace pressure switch to operate properly. When connecting gas supply, factors such as length of run, number of fittings and furnace rating must be considered to avoid excessive pressure drop.
  • Page 38 IMPORTANT FIRE OR EXPLOSION HAZARD Failure to follow the safety warnings exactly could result in serious injury, death, or property damage. Never use an open flame to test for gas leaks. Check all connections using a commercially available soap Figure 60. solution made specifically for leak detection.
  • Page 39 Gas Pipe Capacity - FT³/HR (kL/HR) Nominal Length of Pipe - feet (m) Internal Iron Pipe Diameter Size - - inches inches (3.048) (6.096) (9.144) (12.192) (15.240) (18.288) (21.336) (24.384) (27.432) (30.480) (mm) (mm) .622 (12.7) (17.799) (4.96) (3.40) (2.75) (2.32) (2.07) (1.87)

  • Page 40: Electrical

    Refer to Figure 73 and Figure 75 for field wiring. Refer to Electrical Figure 74 and Figure 76 for schematic wiring diagram and troubleshooting. ELECTROSTATIC DISCHARGE (ESD) The power supply wiring must meet Class I restrictions. Protected by either a fuse or circuit breaker, select Precautions and Procedures circuit protection and wire size according to unit nameplate.
  • Page 41 5% THD (Total Harmonic Distortion). stage thermostat to be used with two stage furnace models (97G2UHV). To activate this option, move the jumper pin (see Figure 66) to desired setting (5 minutes or 10 minutes). The furnace will start on 1st stage heat and stay at 1st stage heat for the duration of the selected time before switching to 2nd stage heat.
  • Page 42 ignition/blower control board and connect a humidity control that opens on humidity rise to the DEHUM and R terminals. The DEHUM terminal on the control board must be connected to the normally closed contact of the humidity control so that the board senses an open circuit on high humidity.
  • Page 43 The circulating blower remains energized until the limits are closed. Fan On When the thermostat is set for continuous fan operation and there is no demand for heating or cooling, a call for fan closes the R to G circuit and the circulating blower motor runs at 38% of the selected cooling CFM until switched off.
  • Page 44 Heat Pump For heat pump operation, clip the jumper wire located below the O terminal on the integrated ignition/blower control board. In heat pump mode, a call for heat will result in the circulating air blower operating at the selected cooling airflow after a brief ramp-up period.
  • Page 45 No demand for high heat High Heat State LED LED On High heat demand, operating normally On 97G2UHV models, a green LED is provided on the control board to indicate high heat state (see Table 11). High heat demand, high pressure switch LED Flashing...
  • Page 46 NEUTRAL L1 HOT 120/1/60 FLAME SENSOR INTERLOCK SWITCH HOT SURFACE IGNITER INDUCED DRAFT BLOWER IND HIGH IND LOW MOTOR HUMIDIFIER AIR CLEANER CHOKE (IF USED) CIRCULATION BLOWER MOTOR 120V TRANSFORMER 2ND STAGE HPS1 LPS1 1ST STAGE GAS VALVE IGNITION CONTROL MOTOR W1 W2 ROLLOUT...
  • Page 47 INDUCED DRAFT GAS VALVE HOT SURFACE PRESSURE BLOWER IGNITOR H1 C M SWITCH (HIGH) PINK ROLLOUT ROLLOUT LIMIT BROWN BLUE PRESSURE 2 PIN SWITCH (LOW) CONNECTOR FLAME SENSOR BROWN BLACK GRN/YLW BLACK INTERLOCK SWITCH IGNITION CONTROL 5 PIN CONNECTOR W1 W2 Y2 0 CIRCULATION BLOWER...
  • Page 48 L1 HOT NEUTRAL 120/1/60 FLAME SENSOR INTERLOCK SWITCH HOT SURFACE IGNITER INDUCED DRAFT BLOWER IND HIGH IND LOW MOTOR HUMIDIFIER AIR CLEANER CHOKE (IF USED) CIRCULATION BLOWER MOTOR 120V TRANSFORMER 2ND STAGE HPS1 LPS1 1ST STAGE GAS VALVE IGNITION CONTROL MOTOR W1 W2 ROLLOUT...
  • Page 49 INDUCED DRAFT GAS VALVE HOT SURFACE PRESSURE BLOWER IGNITOR H1 C M SWITCH (HIGH) PINK ROLLOUT ROLLOUT LIMIT BROWN BLUE PRESSURE 2 PIN SWITCH (LOW) CONNECTOR FLAME SENSOR BROWN BLACK GRN/YLW BLACK INTERLOCK SWITCH IGNITION CONTROL 5 PIN CONNECTOR W1 W2 Y2 0 CIRCULATION BLOWER...

  • Page 50: Blower Performance

    Blower Performance 97G2UH045BV12 Heating CFM @ 0 - 0.8” w.c. Temp. Rise Speed Adjustment Setting D Setting C Setting B Setting A 1005 High Fire Normal 35-65 Low Fire Normal 20-50 Cooling Stage Cooling CFM @ 0 - 0.8” w.c. 1075 1210 1370...
  • Page 51 97G2UH090CV12 Heating CFM @ 0 - 0.8” w.c. Temp. Rise Speed Adjustment Setting D Setting C Setting B Setting A 1060 1135 1240 1430 High Fire Normal 1040 1120 1310 60-90 1175 1040 1120 1310 Low Fire Normal 1195 35-65 1080 Cooling Stage Cooling CFM @ 0 - 0.8”...
  • Page 52 97G2UH110CV20 Heating CFM @ 0 - 0.8” w.c. Temp. Rise Speed Adjustment Setting D Setting C Setting B Setting A 1560 1760 1905 2080 High Fire Normal 1415 1610 1740 1930 45-75 1285 1485 1560 1745 1155 1325 1420 1565 Low Fire Normal 1055...
  • Page 53 Allowable Heating Speeds Model Number Speed Adjust Setting "D" Setting "C" Setting "B" Setting "A" +10% Allowed Allowed Allowed Allowed 97G2UH045BV12 Norm Allowed Allowed Factory Setting Allowed -10% Allowed Allowed Allowed Allowed +10% Allowed Allowed Allowed Not Allowed 97G2UH070BV12 Norm Allowed Allowed Factory Setting...

  • Page 54: Unit Start-Up

    Placing the Furnace into Operation Unit Start-Up This furnace is equipped with an automatic hot surface ignition system. Do not attempt to manually light burners FOR YOUR SAFETY READ BEFORE OPERATING on this furnace. Each time the thermostat calls for heat, the burners will automatically light.
  • Page 55 Turning Off Gas to Unit control will then automatically repeat steps 1 through 6 after 60 minutes. To interrupt the 60 minute period, Set the thermostat to the lowest setting. move thermostat from “Heat” to “OFF” then back to Turn off all electrical power to the unit if service is to “Heat”.

  • Page 56: Other Unit Adjustments

    Pressure Switches For proper furnace operation the minimum gas supply pressure is 4.5” w.c and the maximum gas supply pressure The pressure switches are located in the heating is 10.5” w.c for natural gas. The minimum gas supply compartment on the cold end header box. These switches pressure is 10”...

  • Page 57: Service

    Check amp-draw on the blower motor. Service Motor Nameplate__________Actual__________ Winterizing and Condensate Trap Care WARNING Turn off power to the furnace. Have a shallow pan ready to empty condensate water. ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD. Remove the clean out cap from the condensate trap and empty water.
  • Page 58 18. Mark and disconnect any remaining wiring to heating 39. Secure burner assembly to vestibule panel using four compartment components. Disengage strain relief existing screws. Burners are self aligning to center of bushing and pull wiring and bushing through the hole clam shells.

  • Page 59: Repair Parts List

    Planned Service Repair Parts List A service technician should check the following items during an annual inspection. Power to the unit must be The following repair parts are available through Allied Air shut off for safety. dealers. When ordering parts, include the complete furnace Fresh air grilles and louvers (on the unit and in the model number listed on the CSA nameplate.
  • Page 60 Requirements for Commonwealth of Massachusetts Modifications to NFPA-54, Chapter 10 INSPECTION. The state or local gas inspector of the side wall, horizontally vented, gas-fueled equipment Revise NFPA-54 section 10.8.3 to add the following shall not approve the installation unless, upon requirements: inspection, the inspector observes carbon monoxide For all side wall, horizontally vented, gas-fueled equipment...

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