Page 1: Table Of Contents
INSTALLATION INSTRUCTIONS ©2006 Lennox Industries Inc. Dallas, Texas, USA G40UH(X) Series GAS FURNACE 505,181M 03/2006 Supersedes 505,011M Litho U.S.A. Table of Contents Unit Dimensions ....... . .
Page 2: Unit Dimensions
G40UH(X) Unit Dimensions − inches (mm) 3−3/4 (95) *NOTE − 60C and 60D units that require air volumes over 1800 cfm (850 L/s) must have one of the following: 1. Return air from single side with transition which will accommodate 20 x 25 x 1 in. (508 x 635 x 25 mm) cleanable air filter.
Page 3: G40Uh(X) Parts Arrangement
G40UH(X) Parts Arrangement Air Deflector G40UH−48C−135, G40UH−60C−110, & G40UH−60D−155 Units Only Flue Box Gasket Heat Exchanger Gasket Flue Collector Box Flue Transition Combustion Air Orifice Combustion Air Pressure Switch Combustion Air Inducer Flame Sensor Limit Shield Flame Rollout Switches* Flame Rollout Bracket Primary Limit Gas Valve Insert...
Page 4: G40Uh(X) Gas Furnace
In Canada, installation must conform with current CSA G40UH(X) Gas Furnace B149 Natural Gas and Propane Installation Codes, local plumbing or waste water codes and other applicable local The G40UH(X) gas furnace is shipped ready for installa- codes. tion in the upflow and horizontal position (left or right) Adequate clearance must be made around the air open- fueled by natural gas.
Page 5: General
G40UH(X) furnace: Lennox does not recommend the use of G40UH(X) units as • Place the furnace as close to the center of the air dis- a construction heater during any phase of construction.
Page 6 (outside pressure is greater than inside pressure) will build fans which force air out of the house. When fireplaces, ex- to the point that a downdraft can occur in the furnace vent haust fans, or clothes dryers are used at the same time as pipe or chimney.
Page 7 mm) of the top of the enclosure and one opening within 12 EQUIPMENT IN CONFINED inches (305 mm) of the bottom. See figure 2. SPACE ALL AIR FROM INSIDE CHIMNEY OR GAS Air from Outside VENT If air from outside is brought in for combustion and ventila- tion, the confined space must have two permanent open- ings.
Page 8: Setting Equipment
The G40UH(X) gas furnace can be installed as shipped in either the upflow position or the horizontal position, EQUIPMENT IN CONFINED SPACE ALL AIR FROM OUTSIDE with right-hand or left-hand air discharge. (All Air Through Ventilated Attic) CHIMNEY OR GAS Select a location that allows for the required clearances VENT VENTILATION LOUVERS...
Page 9 Return Air −− Upflow Applications 5 − Return air from bottom and one side. Refer to Engineering Handbook for additional information. Return air can be brought in through the bottom or either side of the furnace installed in an upflow application. If the Side Return Air furnace is installed on a platform with bottom return, make (with transition and filter)
Page 10 Removing the Bottom Panel Leveling Bolt Installation Remove the two screws that secure the bottom cap to the Inches (mm) furnace. Pivot the bottom cap down to release the bottom (10) panel. Once the bottom panel has been removed, reinstall Furnace Front the bottom cap.
Page 11: Figure
This furnace may be installed in either an attic or a crawl- Horizontal Application space. Either suspend the furnace from roof rafters or Unit Installed on Platform floor joists, as shown in figure 12, or install the furnace on NOTE − Line contact is permis- sible.
Page 12: Filters
Filters Venting A 4−inch diameter flue transition is factory-installed on the This unit is not equipped with a filter or rack. A field−pro- combustion air inducer outlet of all models. Modifying or vided high−velocity filter is required for the unit to operate removing the flue transition will cause the unit to oper- properly.
Page 13 Use sheet metal shears to remove the cut out from the side Use self−drilling sheet metal screws or a mechanical fas- of the cabinet. Use the two provided sheet metal screws to tener to firmly secure the vent pipe to the round collar of the install the cut out on the top cap to cover the original flue flue transition.
Page 14 Common Venting Using Tile−Lined Interior Masonry Chimney and Combined Vent Connector MINIMUM LENGTH = AS SHORT AS PRACTICAL. INTERIOR TILE−LINED FOR MAXIMUM LENGTH SEE NOTE TO LEFT MASONRY CHIMNEY NOTE− Refer to provided venting tables for installations in the USA and the venting tables in current CSA−B149 for installations in Canada.
Page 15 5 − The entire length of single wall metal vent connector mended) or other approved means, except vent con- nectors of listed type B vent material which shall be as- shall be readily accessible for inspection, cleaning, sembled according to the manufacturer’s instructions. and replacement.
Page 16 TABLE 3 Capacity of Type B Double−Wall Vents with Type B Double−Wall Connectors Serving a Single Category I Appliance Vent and Connector Diameter − D (inches) Height Lateral 3 Inch 4 Inch 5 Inch 6 Inch Appliance Input Rating in Thousands of Btu Per Hour (feet) (feet) (feet)
Page 17 TABLE 4 Capacity of Type B Double−Wall Vents with Single−Wall Metal Connectors Serving a Single Category I Appliance Vent and Connector Diameter − D (inches) Height Lateral 3 Inch 4 Inch 5 Inch 6 Inch Appliance Input Rating in Thousands of Btu Per Hour (feet) (feet) (feet)
Page 18 TABLE 5 Vent Connector Capacity Type B Double−Wall Vents with Type B Double−Wall Connectors Serving Two or More Category I Appliances Vent and Connector Diameter − D (inches) Vent Vent Connector Connector 3 Inch 4 Inch 5 Inch 6 Inch Height Height Rise...
Page 19 TABLE 7 Vent Connector Capacity Type B Double−Wall Vents with Single−Wall Metal Connectors Serving Two or More Category I Appliances Vent and Connector Diameter − D (inches) Vent Vent Connector Connector 3 Inch 4 Inch 5 Inch 6 Inch Height Height Rise Rise...
Page 20: Gas Piping
Resize the common venting system to the minimum 2 − When connecting the gas supply piping, consider fac- tors such as length of run, number of fittings, and fur- size determined by using the appropriate tables in ap- nace rating to avoid excessive pressure drop. Table 9 pendix G.
Page 21: Electrical
Left Side Piping AUTOMATIC MANUAL (Standard) GAS VALVE MAIN SHUT−OFF MANUAL (with manual VALVE AUTOMATIC MAIN SHUT−OFF shut−off valve) (With 1/8 in. NPT GAS VALVE VALVE Plugged Tap (with manual (With 1/8 in. NPT Shown) shut−off valve) Plugged Tap Shown) GROUND JOINT UNION...
Page 22 NOTE − The G40UH(X) furnace contains electronic INTERIOR MAKE−UP BOX INSTALLATION components that are polarity sensitive. Make sure MAKE−UP that the furnace is wired correctly and is properly Left side grounded. 7 − One line voltage EAC" accessory terminal is provided on the furnace control board.
Page 23 TYPICAL G40UH(X) FIELD WIRING DIAGRAM FIGURE 24 INTEGRATED CONTROL BOARD (Automatic Hot Surface Ignition System) TERMINAL DESIGNATIONS Humidifier (120VAC) LINE Input (120VAC) XFMR Transformer (120VAC) Electronic Air Cleaner (120VAC) COOL Blower − Cooling Speed (120VAC) HEAT Blower − Heating Speed (120VAC) PARK Dead terminals to park alternate spd taps FLAME...
Page 24 G40UH(X) Schematic Wiring Diagram FIGURE 26 Page 24...
Page 25: Unit Start−Up
3 − Turn off all electrical power to the unit. Unit Start−Up 4 − This furnace is equipped with an ignition device which FOR YOUR SAFETY READ BEFORE LIGHTING automatically lights the burners. Do not try to light the burners by hand. 5 −...
Page 26: Gas Pressure Adjustment
8 − Honeywell VR8205 Gas Valve with ON/OFF Switch Gas Pressure Adjustment − Move gas valve switch to ON. See figure 27. Honeywell VR8205 Gas Valve with Control Knob − Gas Flow (Approximate) Turn knob on gas valve counterclockwise to ON. 1 −...
Page 27: High Altitude Information
Gas Pressure Other Unit Adjustments 1 − Check the gas line pressure with the unit firing at maxi- Primary and Secondary Limits mum rate. A minimum of 4.5 in. w.c. for natural gas or The primary limit is located on the heating compartment 11.0 in.
Page 28: Service
Thermostat Heat Anticipation 5 − Is the filter dirty or plugged? Dirty or plugged filters will cause the limit control to shut the unit off. Set the heat anticipator setting (if adjustable) according to 6 − Is gas turned on at the meter? the amp draw listed on the wiring diagram that is attached 7 −...
Page 29 Cleaning the heat exchanger requires a steel spring NOx INSERTS snake," a reversible drill and a vacuum cleaner. The steel (X models only) spring snake may be constructed by purchasing a 4 ft. long by 1/4 inch diameter steel wire cable and a 1/4 inch diame- ter wire brush.
Page 30: Repair Parts List
20− Turn on power and gas supply to unit. 25− Replace front access panel. Repair Parts List The following repair parts are available through Lennox dealers. When ordering parts, include the complete furnace model number listed on the CSA nameplate −− Example: G40UH(X)−24A−045−1. Cabinet Parts...
Page 31: Ignition Control Board Diagnostic Codes
Ignition Control Board Diagnostic Codes DIAGNOSTIC CODES Make sure to Identify LED’S Correctly. Refer to figure NO TAG for control board layout. LED #1 (Red) LED #2 (Green) DESCRIPTION Power on − Normal operation. SIMULTANEOUS SIMULTANEOUS Also signaled during cooling and continuous fan. SLOW FLASH SLOW FLASH SIMULTANEOUS...
Page 32: Troubleshooting
Troubleshooting HEATING SEQUENCE OF OPERATION ABNORMAL HEATING MODE NORMAL HEATING MODE POWER ON GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER DELAY OFF. CONTROL SELF−CHECK OKAY? LED #1 ON LED #2 ON (RESET CONTROL BY TURNING MAIN POWER OFF.) POLARITY REVERSED.
Page 33 Troubleshooting HEATING SEQUENCE CONTINUED NORMAL HEATING MODE ABNORMAL HEATING MODE 15-SECOND COMBUSTION AIR INDUCER PREPURGE INITIATED BY CLOSED PRESSURE SWITCH. LEDS SIGNAL ALTERNATING FAST FLASH UNTIL IGNITER WARM-UP −− 20 SECONDS. IS VOLTAGE ABOVE 90 VOLTS? VOLTAGE IS ABOVE 95 VOLTS, THEN RESTARTS HEATING 4-SECOND TRIAL FOR IGNITION.
Page 34 Troubleshooting 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 35 Troubleshooting CONTINUOUS HEAT 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 HEAT SPEED. EAC TERMINAL IS ENERGIZED. HUM TERM. ENERGIZES THERMOSTAT CALLS FOR HEAT (W). WITH COMB.

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Lennox G40UH Series Installation Instructions Manual

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