Oxbox J951X038BU, J951X072CU, J951X108DU Install Instructions

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Page 1

INSTALLATION INSTRUCTIONS

95.0% AFUESingle Stage Condensing Gas Furnaces

J951X*U (95.0% AFUE)

Upﬂow / Horizontal Furnace

J951X*D (95.0% AFUE)

Downﬂow Furnace

WARNING

FIRE OR EXPLOSION HAZARD

• Failure to follow safety warnings exactly could result in serious injury, death or property damage.

• Installation and service must be performed by a qualiﬁed installer, service agency or the gas supplier.

• Do not store or use gasoline or other ﬂammable vapors and liquids in the vicinity of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not use any phone in your building.

• Leave the building immediately.

• Immediately call your gas supplier from a neighbors phone. Follow the gas suppliers instructions.

• If you cannot reach your gas supplier, call the ﬁre department.

DO NOT DESTROY. PLEASE READ CAREFULLY & KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

Page 2

TABLE OF CONTENTS

IMPORTANT SAFETY INFORMATION .............................. 3

REQUIREMENTS & CODES .............................................. 3

Combustion Air Quality ..................................................... 4

Heating Load .................................................................... 5

Installation in a Garage .................................................... 5

Clearances to Combustible Materials ............................... 5

Operation of Furnace During Construction ....................... 5

COMBUSTION AIR & VENTING REQUIREMENTS .......... 6

Direct Vent Furnaces ........................................................ 7

Conventional Vent Systems - Conﬁned Spaces ............... 7

Air From Inside ............................................................. 7

Outdoor Air from a Crawl Space or Vented Attic .......... 8

Outdoor Air Using Vertical Ducts .................................. 8

Outdoor Air Using Horizontal Ducts ............................. 8

Air Directly Through An Exterior Wall ........................... 9

Alternate Method of Providing Air from Outside ........... 9

Conventional Vent Systems - Unconﬁned Spaces ........... 9

Category IV Venting ......................................................... 9

Vent Pipe Material ........................................................ 10

Vent Pipe Length & Diameter ....................................... 10

Vent Pipe Installation .................................................... 10

Outdoor Terminations - Horizontal Venting .................. 11

Outdoor Terminations - Vertical Venting ...................... 12

Vent Freezing Protection .............................................. 12

Existing Installations ..................................................... 12

Condensate Disposal ....................................................... 12

CIRCULATING AIR REQUIREMENTS ............................... 13

Plenums & Air Ducts ........................................................ 13

Return Air Connections .................................................... 13

Upﬂow & Horizontal Furnaces ...................................... 13

Downﬂow Furnaces ...................................................... 14

Supply Air Connections .................................................... 14

Acoustical Treatments ...................................................... 14

FURNACE INSTALLATION ................................................ 14

General Requirements ..................................................... 14

Upﬂow Furnaces .............................................................. 14

Horizontal Furnaces ......................................................... 14

Downﬂow Furnaces .......................................................... 15

Installation on a Concrete Slab .................................... 15

Inducer & Venting Options ............................................... 15

Inducer Assembly Rotation .......................................... 16

Pressure Switch Tubing ............................................... 16

Alternate Pressure Switch Location ............................. 17

Accessories ...................................................................... 17

Finish Flange ................................................................ 17

Rubber Grommets ........................................................ 17

PVC Components ......................................................... 18

Typical Orientation ................................................... 18

Alternate Orientation ................................................ 18

Optional PVC Pipe Installation ..................................... 18

Condensate Drain Lines ............................................... 18

Bottom Panel Removal ..................................................... 19

Alternate Bottom Panel Removal ..................................... 19

GAS SUPPLY & PIPING ..................................................... 20

Leak Check ...................................................................... 20

High Altitude Application (Natural Gas Only) ................... 20

Converting from Natural Gas to LP / Propane .................. 22

ELECTRICAL WIRING ....................................................... 23

Line Voltage Wiring .......................................................... 23

Grounding ......................................................................... 23

Thermostat / Low Voltage Connections ........................... 24

Twinning ........................................................................... 24

One stage heating ........................................................ 24

Two stage heating ........................................................ 25

Heat Anticipator ................................................................ 25

START-UP & ADJUSTMENTS ........................................... 25

Pre-Start Check List ......................................................... 25

Start-up Procedures ......................................................... 25

Verifying & Adjusting Input Rate ....................................... 25

Verifying & Adjusting Temperature Rise .......................... 26

Verifying Burner Operation ............................................... 26

Verifying Operation of the Supply Air Limit Switch ........... 26

System Operation ............................................................. 26

(Gas) Heating Mode ..................................................... 26

Cooling Mode ............................................................... 26

Manual Fan .................................................................. 26

Fault Conditions ............................................................... 27

OPERATING SEQUENCE .................................................. 27

Heating Cycle ................................................................... 27

Cooling Cycle ................................................................... 27

Fan Mode ......................................................................... 27

MAINTENANCE .................................................................. 27

FIGURES & TABLES .......................................................... 29

Figure 29. J951X*U Cabinet Dimensions ..................... 29

Figure 30. J951X*D Cabinet Dimensions ..................... 29

Figure 31. Wiring Diagram ........................................... 30

Figure 32. Ladder Diagram .......................................... 31

Table 6. Gas Flow Rates .............................................. 32

Table 7. Gas Pipe Capacities ....................................... 32

Table 8. High Altitude Deration – Propane Gas ........... 33

Table 9. Natural Gas Heating Values ........................... 33

Table 10. High Altitude Deration – Natural Gas with

HIGH Heating Value .................................... 34

Table 11. High Altitude Deration – Natural Gas with

LOW Heating Value ..................................... 34

Table 12. Vent Termination Clearances ....................... 35

Figure 33. Horizontal & Vertical Venting ...................... 36

Figure 34. Venting Options for Upﬂow Installations

(J951X*U Series) ........................................ 37

Figure 35. Venting Options for Horizontal Installations

(J951X*U Series) ........................................ 38

Figure 36. Venting Options for Downﬂow Installations

(J951X*D Series) ........................................ 39

TROUBLESHOOTING ........................................................ 40

Table 13. Control Board Fault Conditions .................... 40

FURNACE COMPONENTS ................................................ 40

Table 14. Motor Control Board Fault Conditions .......... 40

Figure 37. J951X*U Component Locations .................. 41

Figure 38. J951X*D Component Locations .................. 41

INSTALLATION CHECKLIST ............................................. 44

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IMPORTANT SAFETY INFORMATION

INSTALLER: Please read all instructions before servicing this equipment. Pay attention to all safety warnings and any other special notes highlighted in the manual. Safety markings are used frequently throughout this manual to designate a degree or level of seriousness and should not be ignored. situation that if not avoided, could result in personal injury or death. that if not avoided, may result in minor or moderate injury or property damage.

WARNING - Indicates a potentially hazardous

CAUTION - Indicates a potentially hazardous situation

kerosene, cigarette lighter ﬂuid, dry cleaning ﬂuids, paint thinners, or other volatile ﬂuids.

• The installer should become familiar with the units wiring diagram before making any electrical connections to the unit. See the unit wiring label.

• Always reinstall the doors on the furnace after

servicing. Do not operate the furnace without all doors and covers in place.

Figure 32 (page 31), Figure 33 (page 36) or

REQUIREMENTS & CODES

WARNING:

The safety information listed in this manual must be followed during the installation, service, and operation of this unit. Unqualiﬁed individuals should not attempt to interpret these instructions or install this equipment. Failure to follow safety recommendations could result in possible damage to the equipment, serious personal injury or death.

WARNING:

Improper installation, service, adjustment, or maintenance may cause explosion, ﬁre, electrical shock or other hazardous conditions which may result in personal injury or property damage. Unless otherwise noted in these instructions, only factory authorized kits or accessories may be used with this product.

WARNING:

Do not install this furnace if any part has been submerged under water. A ﬂood damaged furnace is extremely dangerous. Attempts to use the furnace may result in ﬁre or explosion. A qualiﬁed service agency should be contacted to inspect the furnace and to replace any electrical or control system parts that have been wet or under water.

• To minimize equipment failure or personal injury, it is essential that only qualiﬁed individuals install, service, or maintain this equipment. If you do not posses mechanical skills or tools, call your local dealer for assistance.

• Follow all precautions in the literature, on tags, and on labels provided with the equipment. Read and thoroughly understand the instructions provided with the equipment prior to performing the installation and operational checkout of the equipment.

• Use caution when handling this appliance or removing components. Personal injury can occur from sharp metal edges present in all sheet metal constructed equipment.

• Do not store any of the following on, or in contact with, the unit: Rags, brooms, vacuum cleaners, or other cleaning tools, spray or aerosol cans, soap powders, bleaches, waxes, cleaning compounds, plastics or plastic containers, paper bags or other paper products, gasoline,

WARNING:

The information listed below must be followed during the installation, service, and operation of this furnace. Failure to follow safety recommendations could result in possible damage to the equipment, serious personal injury or death.

• This furnace must be installed in accordance with these instructions, all applicable local building codes and the current revision of the National Fuel Gas Code (NFPA54/ ANSI Z223.1) or the Natural Gas and Propane Installation Code, CAN/CSA B149.1.

• Use only with type of gas approved for this furnace. Refer to the furnace rating plate.

• Install this furnace only in a location and position as speciﬁed on

• Provide adequate combustion and ventilation air to the furnace space as speciﬁed on

page 8

• Provide adequate clearances around the vent air intake terminal as shown in

, Figure 9 (page 12), & Figure 10 (page 12).

11)

• Combustion products must be discharged outdoors. Connect this furnace to an approved vent system only, as speciﬁed on

• Never test for gas leaks with an open ﬂame. Use a commercially available soap solution to check all connections. See

• This furnace is designed to operate with a maximum external pressure rise of 0.5 inches of water column. Consult the rating plate for the proper circulating air ﬂow and temperature rise. It is important that the duct system be designed to provide the correct ﬂow rates and external pressure rise. An improperly designed duct system can result in nuisance shutdowns, and comfort or noise issues.

• When supply ducts carry air circulated by the furnace to areas outside the space containing the furnace, the return air shall also be handled by duct(s) sealed to the furnace casing and terminating in the conditioned space. See

page 13 .

• A gas-ﬁred furnace for installation in a residential garage must be installed as speciﬁed on

• This furnace is not approved for installation in mobile homes. Installing this furnace in a mobile home could cause ﬁre, property damage, and/or personal injury.

• The Commonwealth of Massachusetts requires compliance with regulation 248 CMR 4.00 and 5.00 for installation of through – the – wall vented gas appliances as follows:

page 5.

page 6, page 7,

& page 9.

Figure 7 (page 11), Figure 8 (page

page 9, page 10, page 11, & page

page 20.

page 5.

Page 4

1. For direct-vent appliances, mechanical-vent heating appliances or domestic hot water equipment, where the bottom of the vent terminal and the air intake is installed below four feet above grade the following requirements must be satisﬁed:

a.) A carbon monoxide (CO) detector and alarm shall be

placed on each ﬂoor level where there are bedrooms. The detector shall comply with NFPA 720 (2005 Edition) and be mounted in the living area outside the bedroom(s).

b.) A (CO) detector shall be located in the room that

houses the appliance or equipment and shall:

• Be powered by the same electrical circuit as the appliance or equipment. Only one service switch shall power the appliance and the (CO) detector;

• Have battery back-up power;

• Meet ANSI/UL 2034 Standards and comply with NFPA 720 (2005 Edition); and Approved and listed by a Nationally Recognized Testing Laboratory as recognized under 527 CMR.

c.) A Product-approved vent terminal must be used,

and if applicable, a product-approved air intake must be used. Installation shall be in strict compliance with the manufacturer’s instructions. A copy of the installation instructions shall remain with the appliance or equipment at the completion of the installation.

d.) A metal or plastic identiﬁcation plate shall be mounted

at the exterior of the building, four feet directly above the location of vent terminal. The plate shall be of sufﬁcient size, easily read from a distance of eight feet away, and read “Gas Vent Directly Below”.

2. For direct-vent appliances, mechanical-vent heating appliances or domestic hot water equipment where the bottom of the vent terminal and the air intake is installed above four feet above grade the following requirements must be satisﬁed:

a.) A (CO) detector and alarm shall be placed on each

ﬂoor level where there are bedrooms. The detector shall comply with NFPA 720 (2005 Edition) and be mounted in the living area outside the bedroom(s).

b.) The (CO) detector shall:

• Be located in the room that houses the appliance or equipment;

• Be hard-wired or battery powered or both.

• Shall comply with NFPA 720 (2005 Edition).

c.) A product-approved vent terminal must be used,

The information listed below is for reference purposes only and does not necessarily have jurisdiction over local or state codes. Always consult with local authorities before installing any gas appliance.

Combustion & Ventilation Air

• US: National Fuel Gas Code (NFGC), Air for Combustion and Ventilation

• CANADA: Natural Gas and Propane Installation Codes (NSCNGPIC), Venting Systems and Air Supply for Appliances

Duct Systems

• US and CANADA: Air Conditioning Contractors Association (ACCA) Manual D, Sheet Metal and Air Conditioning Contractors National Association (SMACNA), or American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) Fundamentals Handbook

Electrical Connections

• US: National Electrical Code (NEC) ANSI/NFPA 70

• CANADA: Canadian Electrical Code CSA C22.1

Gas Piping & Gas Pipe Pressure Testing

• US: NFGC and National Plumbing Codes

• CANADA: NSCNGPIC

General Installation

• US: Current edition of the NFGC and the NFPA 90B. For copies, contact the National Fire Protection Association Inc., Batterymarch Park, Quincy, MA 02269; or American Gas Association, 400 N. Capitol, N.W., Washington DC 20001 or www.NFPA.org

• CANADA: NSCNGPIC. For a copy, contact Standard Sales, CSA International, 178 Rexdale Boulevard, Etobicoke (Toronto), Ontario, M9W 1R3 Canada

Safety

• US: (NFGC) NFPA 54–1999/ANSI Z223.1 and the Installation Standards, Warm Air Heating and Air Conditioning Systems ANSI/NFPA 90B.

• CANADA: CAN/CSA-B149.1 and .2–M00 National Standard of Canada. (NSCNGPIC)

Combustion Air Quality

CAUTION:

Combustion air must not be drawn from a corrosive atmosphere.

To maximize heat exchanger life, the combustion air must be free of chemicals that can form corrosive acidic compounds in the combustion gases. The recommended source of combustion air is to use outdoor air. However, the use of indoor air in most applications is acceptable except as listed:

• If the furnace is installed as a single pipe installation

in a conﬁned space, it is required that the necessary combustion air come from the outdoors by way of attic, crawl space, air duct, or direct opening. For Installations in conﬁned spaces, see requirements.

• Installations in these locations may require outdoor air for

combustion, due to chemical exposures:

Commercial buildings Buildings with indoor pools Furnaces installed in laundry rooms Furnaces installed in hobby or craft rooms Furnaces installed near chemical storage areas

page 7 for combustion air

Page 5

UPFLOW

DOWNFLOW

• Exposure to the following substances in the combustion air supply may require outdoor air for combustion:

Permanent wave solutions Chlorinated waxes and cleaners Chlorine based swimming pool chemicals Water softening chemicals De-icing salts or chemicals Carbon Tetrachloride Halogen type refrigerants Cleaning solvents (perchloroethylene) Printing inks, paint removers, varnishes, etc. Hydrochloric Acid Cements and glues Antistatic fabric softeners Masonry acid washing materials

Heating Load

This furnace should be sized to provide the design heating load requirement. Heating load estimates can be made using approved methods available from Air Conditioning Contractors of America (Manual J); American Society of Heating, Refrigerating, and Air Conditioning Engineers; or other approved engineering methods. Excessive oversizing

of the furnace could cause the furnace and/or vent to fail prematurely.

The ductwork should be appropriately sized to the capacity of the furnace to ensure its proper airﬂow rating. For installations above 2,000 ft., the furnace should have a sea level input rating large enough that it will meet the heating load after deration for altitude.

Installation in a Garage

WARNING:

Do not place combustible material on or against the furnace cabinet or within 6 inches of the vent pipe. Do not place combustible materials, including gasoline or any other ﬂammable vapors and liquids, in the vicinity of the furnace.

This gas-ﬁred furnace may be installed in a residential garage with the provision that the burners and igniter are located no less than 18 inches (457mm) above the ﬂoor. The furnace must be located or protected to prevent physical damage by vehicles.

Clearances to Combustible Materials

This furnace is Design Certiﬁed in the U.S. and Canada by CSA International or Underwriter’s Laboratories for the minimum clearances to combustible materials. NOTE: The furnace is listed for installation on combustible or noncombustible ﬂooring. However, wood is the only combustible ﬂooring allowed for installation. Downﬂow models must use the appropriate subase kit when installing over a wood ﬂoor. To obtain model number and speciﬁc clearance information, refer to the furnace rating plate, located inside of the furnace cabinet.

Access for positioning and servicing the unit must be considered when locating unit. The need to provide clearance for access to panels or doors may require clearance distances over and above the requirements. Allow 24 inches minimum

clearance from the front of the unit. However 36 inches is strongly recommended. See

clearance requirements.

Figure 1 for minimum

CLEARANCES TO COMBUSTIBLE MATERIALS

BOTTOM

APPLICATIONS

BACK

TOP

LEFT SIDE

FRONT

†

4 Inches

RIGHT SIDE

VENT

APPLICATIONS

BACK

TOP

LEFT SIDE

FRONT

Left Side..................0 Inches To p .......................... 0 Inches

Right Side ...............0 Inches Front ......................

Vent ......................... 0 Inches Back ........................0 Inches

†Allow 24 in. minimum clearance for servicing. Recommended clearance is 36 in.

RIGHT SIDE

VENT

HORIZONTAL

APPLICATIONS

TOP

VENT

SIDE

FRONT

SIDE

Figure 1. Minimum Clearances to

Combustible Materials

Operation of Furnace During Construction

CAUTION:

Failure to follow these instructions will void the factory warranty and may signiﬁcantly reduce the life or the performance of the furnace, and/ or result in other unsafe conditions. It is the responsibility of the installing contractor to insure these provisions are met.

Operating gas furnaces in construction environments can cause a variety of problems with the furnace. Proper use of commercial portable space heating equipment during construction is recommended. This gas furnace may be used during construction if it is not in violation of any applicable codes and the following criteria are met:

• The installation must meet all applicable codes. The furnace must be permanently installed according to the instructions supplied with the furnace. This includes the electrical supply, gas piping, duct work, and venting. The furnace must be controlled by a room thermostat properly installed according to the instructions supplied with the furnace and thermostat. The installation must include a properly installed air ﬁlter in the return air duct, sealed to the furnace with no by-pass air. The ﬁlter must be inspected frequently and replaced when necessary.

• The furnace input rate and air temperature rise must be checked and veriﬁed to be within the acceptable ranges as marked on the furnace nameplate.

• Before occupying the structure: The air ﬁlter must be replaced or cleaned, the duct work must be inspected and cleaned of any construction debris, and the furnace must be cleaned and/ or repaired if found to be dirty, damaged, or malfunctioning in any way by a qualiﬁed HVAC technician. The furnace shall be inspected and approved by applicable local authority even if this requires redundant inspections.

• Serial numbers for furnaces used during construction must be submitted in writing (fax and email also acceptable). This information will be used to track the long-term affects of the use during construction on furnaces. Proof of this submittal

Page 6

shall be available for the ﬁnal inspection of the furnace prior to occupancy.

• This furnace is designed to operate with return air temperatures in ranges normally found in occupied residences, including setbacks. Minimum continuous return temperature must not be below 60° F (15° C). Occasionally a temporary return temperature of 55° F (12° C) is acceptable. However, operation with a return temperature below 55° F (12° C) is not allowed.

• The installing contractor and / or builder must:

— Comply with the requirements of this section. — Complete the attached Use of Furnace During

Construction checklist.

— Email copy of completed Use of Furnace During

Construction checklist to [email protected]

— Leave original completed Use of Furnace During

Construction checklist with furnace.

— Disclose use of the furnace during construction to the

homeowner in advance of the sale.

COMBUSTION AIR & VENTING

REQUIREMENTS

WARNING:

CARBON MONOXIDE POISONING HAZARD Failure to follow the steps outlined below for each appliance connected to the venting system being placed into operation could result in carbon monoxide poisoning or death.

The following steps shall be followed with each individual appliance connected to the venting system being placed in operation, while all other appliances connected to the venting system are not in operation:

1. Seal any unused openings in the venting

system.

2. Inspect the venting system for proper size and

horizontal pitch, as required in the National Fuel Gas Code, ANSI Z223.1/NFPA 54 or the CSA B149.1, Natural Gas and Propane Installation Codes and these instructions. Determine that there is no blockage or restriction, leakage, corrosion and other deﬁciencies which could cause an unsafe condition.

3. As far as practical, close all building doors

and windows and all doors between the space in which the appliance(s) connected to the venting system are located and other spaces of the building.

4. Close ﬁreplace dampers.

5. Turn on clothes dryers and any appliance

not connected to the venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they are operating at maximum speed. Do not operate a summer exhaust fan.

6. Follow the lighting instructions. Place the

appliance being inspected into operation. Adjust the thermostat so appliance is operating continuously.

7. Test for spillage from draft hood equipped

appliances at the draft hood relief opening after 5 minutes of main burner operation. Use the ﬂame of a match or candle.

8. If improper venting is observed during any of

the above tests, the venting system must be corrected in accordance with the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or CSA B149.1, Natural Gas and Propane Installation Codes.

9. After it has been determined that each

appliance connected to the venting system properly vents when tested as outlined above, return doors, windows, exhaust fans, ﬁreplace dampers and any other gas-ﬁred burning appliance to their previous conditions of use.

Page 7

IMPORTANT INFORMATION:

• This furnace must be vented in compliance with the current revision of the National Fuel Gas Code (ANSI-Z223.1/NFPA54). Instructions for determining the adequacy of an installation can be found in the current revision of the NFGC (ANSI Z223.1 / NFPA54). Refer to the NFGC for approved vent tables. Consult local codes for special requirements. These requirements are for US installations as found in the NFGC.

• Furnace installation using methods other than those described in the following sections must comply with the National Fuel Gas Code (NFGC) and all applicable local codes.

• Requirements in Canada (B149.1) are structured differently. In Canada, venting shall conform to the requirements of the current (CAN/CSA B149.1) installation codes. Consult local codes for special requirements.

• Provisions must be made during the installation of this furnace that provide an adequate supply of air for combustion. The combustion air from the outside needs to be clear of chemicals that can cause corrosion. The inlet pipe should not be placed near corrosive chemicals such as those listed on

page 5.

WARNING:

Upon completion of the furnace installation, carefully inspect the entire ﬂue system both inside and outside the furnace to assure it is properly sealed. Leaks in the ﬂue system can result in serious personal injury or death due to exposure of ﬂue products, including carbon monoxide.

WARNING:

This furnace must not be vented with other appliances, even if that appliance is of the condensing type. Common venting can result in severe corrosion of other appliances or their venting and can allow combustion gases to escape through such appliances or vents. Do not vent the furnace to a ﬁreplace chimney or building chase.

This condensing furnace is certiﬁed for installation either as a Direct Vent (2-pipe) or Conventional (1-pipe) appliance. Direct Vent appliances draw combustion air from the outdoors and vent combustion products back outside. Installation with air taken from around the furnace is often referred to as Conventional installation - i.e. only the vent (exhaust) pipe is provided.

Another important consideration when selecting one or two pipe installation is the quality of the Indoor air which can sometimes be contaminated with various household chemicals . These chemicals can cause severe corrosion in the furnace combustion system. A 2-pipe installation has the additional advantage that it isolates the system from the effects of negative pressure in the house.

CAUTION:

Exhaust fans, clothes dryers, ﬁreplaces and other appliances that force air from the house to the outdoors can create a negative pressure inside the house, resulting in improper furnace operation or unsafe conditions such as ﬂame roll out. It is imperative that sufﬁcient air exchange with the outdoors is provided to prevent depressurization. Additional information about how to test for negative pressure problems can be found in the NFGC.

Air openings on top of the furnace and openings in closet doors or walls must never be restricted. If the furnace is operated without adequate air for combustion, the ﬂame rollout switch will open, turning off the gas supply to the burners.

IMPORTANT NOTE

This safety device is a manually reset switch. DO NOT install jumper wires across these switches to defeat their function or reset a switch without identifying and correcting the fault condition. If a switch must be replaced, use only the correct sized part speciﬁed in the Replacement Parts List provided online.

Direct Vent Furnaces

Direct Vent (2-pipe) furnaces draw combustion air directly from the outdoors and then vent the combustion products back outside, isolating the entire system from the indoor space. It is important to make sure that the whole system is sealed and clearances to combustibles are maintained regardless of the installation being in a conﬁned or unconﬁned space.

Conventional Vent Systems - Conﬁned Spaces

A conﬁned space is an area with volume less than 50 cubic feet per 1,000 Btuh of the combined input rates of all appliances drawing combustion air from that space. Furnace closets, small equipment rooms and garages are conﬁned spaces. Furnaces installed in a conﬁned space which supply heated air to areas outside the space must draw return air from outside the space and must have the return air ducts tightly sealed to the furnace. Ducts must have cross - sectional area at least as large as the free area of their respective openings to the furnace space. Attics or crawl spaces must connect freely with the outdoors if they are the source of air for combustion and ventilation.

The required sizing of these openings is determined by whether inside or outside air is used to support combustion, the method by which the air is brought to the space, and by the total input rate of all appliances in the space. In all cases, the minimum dimension of any combustion air opening is 3 inches.

Air From Inside

If combustion air is taken from the heated space, the two openings must each have a free area of at least one square inch per 1,000 Btuh of total input of all appliances in the conﬁned space, but not less than 100 square inches of free area. See

Example and Figure 2.

Page 8

EXAMPLE

Notes

NOTES:

Each opening must be at least 100 sq. in. or 1 sq. in. per 1,000 Btuh of total input rating, whichever is greater.

Openings must start at no more than 12 inches from the top and bottom of the enclosure.

per 4,000 Btuh of

Air Duct must be

per 4,000 Btuh of

Ventilation Louvers

12" Max

Unheated Crawl Space

Alter

Air Ducts must be

If the combined input rate of all appliances is less than or equal to 100,000 Btuh, each opening must have a free area of at least 100 in appliances is 120,000 Btuh, each opening must have a free area of at least 120 in

Vent or

Chimney

. If the combined input rate of all

Outdoor Air Using Vertical Ducts

If combustion air is taken from outdoors through vertical ducts, the openings and ducts must have a minimum free area of one square inch per 4,000 Btuh of total appliance input. See

Figure 4 (page 8).

Outdoor Air Using Horizontal Ducts

If combustion air is taken from outdoors through horizontal ducts, the openings and ducts must have a minimum free area of one square inch per 2,000 Btuh of total appliance input. Ducts must have cross - sectional area at least as large as the free area of their respective openings to the furnace space. See

Figure 5.

12” Max.

See

Water Heater

Furnace

See

TOTAL INPUT

RATING (BTUH)

Notes

MINIMUM FREE AREA

(EACH OPENING)

12” Max.

ROUND DUCT

DIAMETER

40,000 100 sq. In 12 inches 60,000 100 sq. In 12 inches

80,000 100 sq. In 12 inches 100,000 100 sq. In 12 inches 120,000 120 sq. In 13 inches 140,000 140 sq. In 14 inches 160,000 160 sq. In 15 inches

Figure 2. Combustion Air Drawn from Inside

Outdoor Air from a Crawl Space or Vented Attic

When the openings can freely exchange air with the outdoors, each opening shall have a minimum free area of 1 square inch per 4,000 Btuh of total appliance input. The openings shall exchange directly, or by ducts, with the outdoor spaces (crawl or attic) that freely exchange with the outdoors. See

Figure 3 (page 8).

at each end of attic

Vent or

Chimney

TOTAL INPUT

RATING (BTUH)

40,000 10 sq. In 4 inches

60,000 15 sq. In 5 inches

80,000 20 sq. In 5 inches

100,000 25 sq. In 6 inches

120,000 30 sq. In 6 inches

140,000 35 sq. In 7 inches

160,000 40 sq. In 8 inches

Attic

Insulation

Water

Furnace

Heater

MINIMUM FREE AREA

(EACH OPENING)

at least 1 sq. in.

total input rating.

Ducts must extend above attic insulation.

Air Duct must be at least 1 sq. in.

total input rating.

ROUND DUCT

DIAMETER

Figure 3. Combustion Air Drawn from Outside

Through Vertical Ducts

Vent or

Chimney

Vent or

Chimney

Ventilation Louvers (each end of attic)

Water Heater

Inlet Air

---------

NOTE: Air openings shall

each have a free area of not less than one square inch per 4,000 Btuh of the total input rating of all equipment in the enclosure

---------

Outlet Air

Furnace

nate

Air Inlet

---------

Ventilation Louvers For

Figure 4. Combustion Air Drawn from a Crawl

Space or Vented Attic

Air Duct

Furnace

Air Duct

MINIMUM FREE AREA

(EACH OPENING)

at least 1 sq. in. per 2,000 Btuh of total input rating.

ROUND DUCT

DIAMETER

TOTAL INPUT

RATING (BTUH)

Water Heater

40,000 20 sq. In 5 inches 60,000 30 sq. In 6 inches

80,000 40 sq. In 7 inches 100,000 50 sq. In 8 inches 120,000 60 sq. In 9 inches 140,000 70 sq. In 10 inches 160,000 80 sq. In 10 inches

Figure 5. Combustion Air Drawn from Outside

Through Horizontal Ducts

Page 9

Air Directly Through An Exterior Wall

Each opening to outside

12" Max.

If combustion air is provided directly through an exterior wall, the two openings must each have free area of at least one square inch per 4,000 Btuh of total appliance input. See

Figure 6.

Vent or

Chimney

See

Note

See

Note

Max

12"

Water Heater

NOTE:

must be at least 1 sq. in. per 4,000 Btuh of total input rating.

Furnace

Conventional Vent Systems - Unconfined Spaces

An unconﬁned space is an area including all rooms not separated by doors with a volume greater than 50 cubic feet per 1,000 Btuh of the combined input rates of all appliances which draw combustion air from that space.

In general, a furnace installed in an unconﬁned space will not require outside air for combustion. However, in homes built for energy efﬁciency (low air change rates), it may be necessary to provide outside air to ensure adequate combustion and venting, even though the furnace is located in an unconﬁned space. See

A space with a water heater rated at 45,000 Btuh input and a furnace rated at 75,000 Btuh requires a volume of 6,000 cubic feet [50 x (45 + 75) = 6,000] to be considered unconﬁned. If the space has an 8 foot ceiling, the ﬂoor area of the space must be 750 sq. ft. (6,000 / 8 = 750).

Example below.

EXAMPLE

TOTAL INPUT

RATING (BTUH)

40,000 10 sq. In 4 inches 60,000 15 sq. In 5 inches

80,000 20 sq. In 5 inches 100,000 25 sq. In 6 inches 120,000 30 sq. In 6 inches 140,000 35 sq. In 7 inches 160,000 40 sq. In 8 inches

MINIMUM FREE AREA

(EACH OPENING)

ROUND DUCT

DIAMETER

Figure 6. Combustion Air Drawn from Outside

Through an Exterior Wall

Alternate Method of Providing Air from Outside

If acceptable under local Codes, it is permitted to provide outside air using one opening (See NFGC). Generally, conﬁned spaces must have two openings in the space for combustion air. One opening must be within 12 inches of the ceiling, and the other must be within 12 inches of the ﬂoor. However, an alternative method recently adopted by the NFGC uses one opening within 12 inches of the top of the space. This method may be used if it is acceptable to the local codes.

THE FOLLOWING CONDITIONS MUST BE MET:

1. The opening must start within 12” of the top of the structure and connect with the out of doors through vertical or horizontal ducts or be ducted to a crawl or attic space that connects with the out of doors.

2. The opening must have a minimum free area of 1 sq. in. per 3,000 Btu per hour of the total input rating of all equipment located in the enclosure.

3. The free area must not be less than the sum of all the areas of the vent connectors in the enclosure.

Category IV Venting

WARNING:

This furnace is classiﬁed as a “Category IV” appliance, which requires special venting materials and installation procedures. This section speciﬁes installation requirements for Conventional (1-pipe) and Direct Vent (2-pipe) piping.

For 1- pipe installations, install vent piping as described in this section and provide air for combustion and ventilation

according to The length of vent and combustion air piping for either type of installation are llisted in

Category IV appliances operate with positive vent pressure and therefore require vent systems which are thoroughly sealed. They also produce liquid condensate, which is slightly acidic and can cause severe corrosion of ordinary venting materials. Furnace operation can be adversely affected by restrictive vent and combustion air piping.

The inducer assembly on this furnace can be rotated to vent the ﬂue products out of the top, left or right side. This increases the ﬂexibility of which direction the vent pipe can exit the furnace.

page 6 , page 7, page 8 & page 9 .

Table 1.

Page 10

Vent Pipe Material

Vent and combustion air pipe and ﬁttings must be one of the following materials in the list and must conform to the indicated ANSI/ASTM standards.

MATERIALS STANDARDS

Schedule 40PVC ......................................................D1785

CPVC ........................................................................D1784

PVC-DWV .................................................................D2665

SDR-21 & SDR-26 ....................................................D2241

ABS-DWV ................................................................. D2661

Schedule 40 ABS .....................................................F628

Foam / Cellular Core PVC ........................................ F891

*PolyPro

*When using PolyPro®, all venting and ﬁttings must be from the same manufacturer with no interchanging of other materials. Refer to speciﬁc instructions supplied with the PolyPro vent kits

by DuraVent ............................................. ULC-S636

When joining PVC to PVC, use cement that conforms to ASTM standard D2564. PVC primer must meet standard ASTM F656. When joining ABS to ABS, use cement that conforms to ASTM standard D2235. When joining PVC to ABS, use cement as speciﬁed in procedure from ASTM standard D3138

In Canada, all plastic vent pipes and ﬁttings including any cement, cleaners, or primers must be certiﬁed as a system to ULC S636. However this requirement does not apply to the ﬁnish ﬂanges or piping internal to the furnace.

Vent Pipe Length & Diameter

In order for the furnace to operate properly, the combustion air and vent piping must not be excessively restrictive.

• The venting system should be designed to have the

minimum number of elbows or turns.

• Transition to the ﬁnal vent diameter should be done as

close to the furnace outlet as practical.

• Always use the same size or a larger pipe for combustion

air that is used for the exhaust vent.

Table 1 (page 10) indicates the maximum allowable pipe

length for a furnace of known input rate, when installed with piping of selected diameter and number of elbows. To use the table, the furnace input rate, the centerline length and the number of elbows on each pipe must be known.

When estimating the length of vent runs, consideration must be made to the effect of elbows and other ﬁttings. This is conveniently handled using the idea of “equivalent length”. This means the ﬁttings are assigned a linear length that accounts for the pressure drop they will cause. For example: a 2” diameter, long radius elbow is worth the equivalent of

2.5 feet of linear run. A 90 degree tee is worth 7 ft.

The equivalent lenghts of tees and various elbows are listed in

Table 1. Measure the linear length of your vent run and

then add in the equivalent length of each ﬁtting. The total length, including the equivalent ﬁtting lengths, must be less than the maximum length speciﬁed in the table.

Vent Pipe Installation

CAUTION:

Combustion air must not be drawn from a corrosive atmosphere.

This furnace has been certiﬁed for installation with zero clearance between vent piping and combustible surfaces. However, it is good practice to allow space for convenience in installation and service.

• In the absence of local codes, the location of any combustion air inlet relative to any vent terminal must be at least 8 inches. This includes installations involving more than one furnace.

• The quality of outdoor air must also be considered. Be sure that the combustion air intake is not located near a source of solvent fumes or other chemicals which can cause corrosion of the furnace combustion system. (See

page 5 for a sample list of substances).

FURNACE

MODELS

(BTU)

38,000 Upﬂow 50 70 50 70

54,000

72,000

85,000 Upﬂow 60 90 60 90

90,000

108,000 Upﬂow N/A 90 N/A 90

115,000 Upﬂow N/A 90 N/A 90

120,000 Upﬂow N/A 90 N/A 90

1. Subtract 2.5 ft. for each additional 2 inch long radius elbow, 5 ft. for each additional 2 inch short radius elbow, 3.5 ft. for each additional 3 inch long radius elbow, and 7 ft. for each additional 3 inch short radius elbow. Subtract 5 ft for each 2” tee and 8 ft for each 3” tee.

2. Two 45 degree elbows are equivalent to one 90 degree elbow.

3. This table applies for elevations from sea level to 2,000 ft. For higher elevations, decrease pipe lengths by 8% per 1,000 ft of altitude.

4. A long radius elbow’s centerline radius is equal to or greater than 1.5 times the vent diameter.

FURNACE

INSTALLATION

Upﬂow 70 90 70 90

Downﬂow 70 90 70 90

Upﬂow 50 90 50 90

Downﬂow 50 90 50 90

Upﬂow 60 90 60 90

Downﬂow 60 90 60 90

SINGLE VENT PIPE LENGTH (FT.)

WITH 1 LONG RADIUS ELBOW†

OUTLET

2” DIAMETER

OUTLET

3” DIAMETER

†

NOTES:

DUAL VENT PIPE LENGTH (FT.)

WITH 1 LONG RADIUS ELBOW ON EACH PIPE†

INLET / OUTLET

2” DIAMETER

INLET / OUTLET

3” DIAMETER

Table 1. Vent Pipe Lengths

Page 11

• Route piping as direct as possible between the furnace

12” min. to maximum

expected snow level

(both pipes)

90° Elbow

Exhaust vent

option B

Exhaust vent

option A

Mounting kit faceplate

secured to wall with screws

(both pipes)

Combustion

air inlet

Exhaust vent

option C

18” Min.

36” Max.

8” Min.

36” Max.

(all positions)

Note 2

Mechanical draft vent terminal

Direct vent terminal

50,000 Btuh

or less

Forced air inlet

Direct vent

terminal - more

than 50,000 Btuh

Mechanical

draft vent

terminal

Mechanical

draft vent

terminal

Less

than

10 ft.

3 ft.

NOTES:

1. All dimensions shown are minimum requirements.

2. Exterior vent terminations must be located at least 12” above the maximum expected snow level.

Note 2

4 ft

12 in.

9 in.

Note 2

and the outdoors. Horizontal piping from inducer to the ﬂue pipe must be sloped 1/4” per foot to ensure condensate ﬂows towards the drain tee or PVC trap. Longer vent runs require larger pipe diameters. Refer to the Inducer & Venting Options section on

page 15 for

additional information.

• If a Direct Vent (2-pipe) system is used, the combustion air intake and the vent exhaust must be located in the same atmospheric pressure zone. This means both pipes must exit the building through the same portion of exterior wall or roof as shown in

Figure 33 (page 36).

• Piping must be mechanically supported so that its weight does not bear on the furnace. Pipe supports must be installed a minimum of every ﬁve feet along the vent run to ensure no displacement after installation. Supports may be at shorter intervals if necessary to ensure that there are no sagging sections that can trap condensate. It is recommended to install couplings along the vent pipe, on either side of the exterior wall (

Figure 33). These

couplings may be required by local code.

• If breakable connections are required in the combustion air inlet pipe (if present) and exhaust vent piping, then straight neoprene couplings for 2” or 3” piping with hose clamps can be used. These couplings can be ordered through your local furnace distributor. To install a coupling:

1. Slide the rubber coupling over the end of the pipe that is

attached to the furnace and secure it with one of the hose clamps.

2. Slide the other end of the rubber coupling onto the other

pipe from the vent.

3. Secure the coupling with the second hose clamp, ensuring

that the connection is tight and leak free.

Figure 7. Inlet & Exhaust Pipe Clearances

Outdoor Terminations - Horizontal Venting

• Vent and combustion air intake terminations shall be installed as shown in with these instructions:

• Vent termination clearances must be consistent with the NFGC, ANSI 2223.1/NFPA 54 and/or the CSA B149.1, Natural Gas and Propane Installation Code.

(page 35)

termination to windows and building air intakes.

• Vent and combustion air intake terminations must be located to ensure proper furnace operation and conformance to applicable codes. A vent terminal must be located at least 3 feet above any forced air inlet located within 10 feet. This does not apply to the combustion air inlet of a direct vent (two pipe) appliance. In Canada, CSA B149.1 takes precedence over these instructions. See

Table 12.

• All minimum clearances must be maintained to protect building materials from degradation by ﬂue gases. See (

Figure 8).

• For optimal performance, vent the furnace through a wall that experiences the least exposure to winter winds.

• The vent termination shall be located at least 3 ft. horizontally from any electric meter, gas meter, regulator and any relief equipment. These distances apply ONLY to U.S. installations. In Canada, CSA B149.1 takes precedence over these instructions.

Figure 7 & Figure 8 and in accordance

Table 12

lists the necessary distances from the vent

Figure 8. Vent Locations

• Do not install the vent terminal such that exhaust is directed into window wells, stairwells, under decks or into alcoves or similar recessed areas, and do not terminate above any public walkways.

• If venting horizontally, a side wall vent kit is available according to the pipe diameter size of the installation. 2 inch and 3 inch kits are available. Refer to the technical sales literature for part numbers. Please follow the

instructions provided with the kit.

• Concentric vent termination kits are available for use with these furnaces. Refer to the technical sales literature for kit numbers.

• When the vent pipe must exit an exterior wall close to the grade or expected snow level where it is not possible to obtain clearances shown in provided as shown in

Figure 9 (page 12). Insulation is

Figure 7, a riser may be

required to prevent freezing of this section of pipe. See

Table 3 (page 15) for vent freezing protection.

Page 12

Support

NOTE: Vent Configuration to Provide 12" Minimum height above Snow Level.

1/2" Armaflex Insulation or Equivalent (if required)

12" Above

Maximum

Expected

Snow Level

19" Max.

(See Note)

Outside

Wall

inlet must be positioned pointing

Plumbing Vent Roof Boot

WINTER DESIGN

TEMPERATURE

20 45 70

0 20 70

-20 10 60

*NOTE: Insulation thickness greater than 3/8 inch, based on an R value of 3.5 (ft x F x hr) / (BTU x in.)

MAXIMUM FLUE PIPE LENGTH (FEET)

IN UNCONDITIONED & EXTERIOR SPACES

WITHOUT INSULATION WITH INSULATION*

Table 2. Vent Protection

Figure 9. Alternate Horizontal Vent Installation

Outdoor Terminations - Vertical Venting

Termination spacing requirements from the roof and from each other are shown in be properly ﬂashed and waterproofed with a plumbing roof boot or equivalent ﬂashing. Vent and combustion air piping may be installed in an existing chimney which is not in use provided that:

• Both the exhaust vent and air intake run the length of the chimney.

• The top of the chimney is sealed and weatherproofed.

• The termination clearances shown in maintained.

• No other gas ﬁred or fuel-burning equipment is vented through the chimney.

Vent Freezing Protection

When the vent pipe is exposed to temperatures below freezing (i.e., when it passes through unheated spaces, chimneys, etc.) the pipe must be insulated with 1/2 inch thick sponge rubber insulation, Armaﬂex-type insulation or equivalent. Insulating pipe is important to avoid condensate icing.

• Table 2 lists the maximum length of ﬂue pipe that can travel through an unconditioned space or an exterior space. The total vent length must not exceed the lengths noted in please refer to the Canadian Installation Code (CAN/ CSA-B149.1 or 2) and/or local codes.

• For extremely cold climates or for conditions of short furnace cycles (i.e. set back thermostat conditions) the last 18 inches of vent pipe can be reduced. It is acceptable to reduce from 3” to 2-1/2”, 3” to 2”, or 2” to 1-1/2” if the total vent length is at least 15 feet in length, and the vent length is within the parameters speciﬁed in

Table 1. The restriction should be counted as 3 equivalent

feet. Smaller vent pipes are less susceptible to freezing, but must not be excessively restrictive. The length of the 2 inch pipe must not be longer than 18 inches.

Figure 10. The roof penetration must

Figure 10 are

CAUTION:

Table 1 (page 10). For Canadian installations,

Elbows on the combustion air

away from the exhaust vent.

12” Above Maximum

Expected Snow Level

(Both pipes)

(Both Pipes)

Combustion Air

8" Min. 36" Max.

Exhaust Vent

Figure 10. Vertical Vent Termination

• If furnace is installed horiziontally, make sure the drainage port on the in-line drain assembly is pointed downward to ensure proper drainage of condensate. For J951X*U series, see

Figure 35 (page 38).

• To prevent debris or creatures from entering the combustion system, a protective screen may be installed over the combustion air intake opening. The screens hole size must be large enough to prevent air restriction.

Existing Installations

When an existing furnace is removed from a vent system serving other appliances, the existing vent system may not be sized properly to vent the remaining appliances (For example: water heater). An improperly sized venting system can result in the formation of condensate, leakage, or spillage. The existing vent system should be checked to make sure it is in compliance with NFGC and must be brought into compliance before installing the furnace.

NOTE: If replacing an existing furnace, it is possible you will encounter an existing plastic venting system that is subject to a Consumer Product Safety Commission recall. The pipes involved in the recall are High Temperature Plastic Vent (HTPV). If your venting system contains these pipes DO NOT reuse this venting system! This recall does not apply to other plastic vent pipes, such as white PVC or CPVC. Check for details on the CPSC website or call their toll-free number (800) 758-3688.

Condensate Disposal

The method for disposing of condensate varies according to local codes. Consult your local code or authority having jurisdiction. Neutralizer kit is available for use with this furnace. Refer to the technical sales literature for part numbers. Please follow the instructions provided with the kit.

This furnace has multiple options for positioning the vent pipe as described in the, Vent and Inducer Assembly Options section ( be J-trapped using ﬁeld supplied parts. After the condensate lines are J-trapped, they may be combined together when routed to the drain.

page 15). Each of the condensate drain lines must

Page 13

For Installations where there is limited clearance for the J-Trap (such as an attic where it may be installed between ceiling joists), either side of the J-Trap can be shortened to a minimum of 3 Inches. See

Figure 11 (page 15).

CIRCULATING AIR REQUIREMENTS

WARNING:

Do not allow combustion products to enter the circulating air supply. Failure to prevent the circulation of combustion products into the living space can create potentially hazardous conditions including carbon monoxide poisoning that could result in personal injury or death.

All return ductwork must be secured to the furnace with sheet metal screws. For installations in conﬁned spaces, all return ductwork must be adequately sealed. When return air is provided through the bottom of the furnace, the joint between the furnace and the return air plenum must be air tight.

The surface that the furnace is mounted on must provide sound physical support of the furnace with no gaps, cracks or sagging between the furnace and the ﬂoor or platform.

Return air and circulating air ductwork must not be connected to any other heat producing device such as a ﬁreplace insert, stove, etc. This may result in ﬁre, explosion, carbon monoxide poisoning, personal injury, or property damage.

• When a cooling system is installed which uses the furnace blower to provide airﬂow over the indoor coil, the coil must be installed downstream (on the outlet side) of the furnace or in parallel with the furnace.

• If a cooling system is installed in parallel with the furnace, a damper must be installed to prevent chilled air from entering the furnace and condensing on the heat exchanger. If a manually operated damper is installed, it must be designed so that operation of the furnace is prevented when the damper is in the cooling position and operation of the cooling system is prevented when the damper is in the heating position.

• Seal all connections and joints with industrial grade sealing tape or liquid sealant. Requirements for sealing ductwork vary from region to region. Consult with local codes for requirements speciﬁc to your area.

Return Air Connections

• In applications where the supply ducts carry heated air to areas outside the space where the furnace is installed, the return air must be delivered to the furnace by duct(s) secured to the furnace casing, running full size and

without interruption. Do not use the back of the furnace

for return air.

• Position the furnace with the return air ductwork ensuring even alignment of furnace (or coil casing) air opening and return air duct. NOTE: The ductwork must have an opening equal to that of the return air opening of the furnace (or coil casing). See

Figure 30 (page 29) for return air opening size.

Figure 29 (page 29) or

Upﬂow & Horizontal Furnaces

• The return air ductwork may be connected to the left side, right side, or bottom of the furnace. NOTE: If using the left or right side of the furnace for return air, the bottom panel (Figure 32) must not be removed from the bottom of the furnace.

Plenums & Air Ducts

• Plenums and air ducts must be installed in accordance with the Standard for the Installation of Air Conditioning and Ventilating Systems (NFPA No. 90A) or the Standard for the Installation of Warm Air Heating and Air Conditioning Systems (NFPA No. 90B).

• On upﬂow furnaces, if the maximum airﬂow is 1,600 CFM or more, two openings shall be used for return air to comply with government mandated efﬁciency standards. Downﬂow furnaces can only use one return opening.

• It is recommended that the outlet duct contain a removable access panel. The opening should be accessible when the furnace is installed in service and shall be of a size that smoke or reﬂected light may be observed inside the casing to indicate the presence of leaks in the heat exchanger. The cover for the opening shall be attached in a way that prevent leaks.

• If outside air is used as return air to the furnace for ventilation or to improve indoor air quality, the system must be designed so that the return air is not less than 60° F (15° C) during operation. If a combination of indoor and outdoor air is used, the ducts and damper system must be designed so that the return air supply to the furnace is equal to the return air supply under normal, indoor return air applications.

WARNING:

The bottom panel of the furnace must be in place when the furnace is installed with side return air ducts. Removal of all or part of the base could cause circulation of combustible products into the living space and create potentially hazardous conditions, including carbon monoxide poisoning that could result in personal injury or death.

• Side Return Installations: To attach the return air duct to the left or right side of the furnace, punch out the 4 knockouts from the side of the furnace ( Using sharp metal cutters, cut an opening between all 4 knockouts to expose the blower assembly. Position the return air duct over the opening and secure to the side with sheet metal screws.

• Bottom Return Installations: If using the bottom of the furnace for return air, the bottom panel ( be removed from the bottom of the furnace. See

for removal instructions. Position the furnace over

the return air duct and secure together with sheet metal screws. Make sure the screws penetrate the duct and furnace casing.

Figure 30).

Figure 30) must

page

Page 14

Downﬂow Furnaces

• To attach the return air duct to the furnace, bend the ﬂanges on the furnace upward 90° with wide duct pliers. See

Figure 29 for furnace ﬂange locations. NOTE: If

system installation includes AC coil casing, bend the ﬂanges on the coil casing upward 90° before attaching the return air duct.

• Secure the return air ductwork to the furnace or coil casing (if installed) with sheet metal screws. Make sure the screws penetrate the sheet metal casing and ﬂanges.

Supply Air Connections

• The supply air must be delivered to the heated space by duct(s) secured to the furnace or coil box casing, running full size and without interruption.

• To attach the supply air duct to upﬂow & horizontal furnaces, bend the ﬂanges on the furnace upward 90° with wide duct pliers. See locations. NOTE: If system installation includes AC coil casing, bend the ﬂanges on the coil casing upward 90° before attaching the supply air duct.

• Position the supply air ductwork onto the furnace ensuring even alignment of furnace air opening and supply air duct. NOTE: The ductwork must have an opening equal to that of the supply air opening of the furnace. See

29 (page 29)

opening size.

and Figure 30 (page 29) for supply air

Figure 30 for furnace ﬂange

Figure

Acoustical Treatments

Damping ducts, ﬂexible vibration isolators, or pleated mediastyle ﬁlters on the return air inlet of the furnace may be used to reduce the transmission of equipment noise eminating from the furnace. These treatments can produce a quieter installation, particularly in the heated space. However, they can increase the pressure drop in the duct system. Care must be taken to maintain the proper maximum pressure rise across the furnace, temperature rise and ﬂow rate. This may mean increasing the duct size and/or reducing the blower speed. These treatments must be constructed and installed in accordance with NFPA and SMACNA construction standards. Consult with local codes for special requirements. For best sound performance, install all the needed gaskets and grommets around penetrations into the furnace, such as for electrical wiring.

FURNACE INSTALLATION

J951X*U series gas furnaces offer a wide range of installation options, including installation in the upﬂow or horizontal positions with either right, left, or upﬂow return air. J951X*D series gas furnaces may only be installed as a downﬂow application.

General Requirements

• The furnace must be leveled at installation and attached to a properly installed duct system. See

for the required clearances needed to move the

furnace to its installation point (hallways, doorways, stairs, etc).

• The furnace must be installed so that all electrical components are protected from water.

• The furnace must be installed upstream from a refrigeration system. (If applicable)

• The cabinet plug must always be used to close the hole in the side of the furnace when rotating the inducer.

• The furnace requires special venting materials and installation procedures. See

, page 9, page 10, page 11, & page 12 for

venting guidelines and speciﬁcations.

page 6, page 7, page

Figure 1 (page

Upﬂow Furnaces

WARNING:

The furnace must not be installed directly on carpeting, tile, or any combustible material other than wood ﬂooring.

J951X*U series gas furnaces are shipped with the bottom panel installed as shown in furnace is installed with only side return air, the bottom panel must not be removed. If the furnace is installed with bottom return air, the bottom panel must be removed. See Bottom Panel Removal on

page 19.

Figure 30 (page 29). If the

Horizontal Furnaces

WARNING:

The furnace must not be installed directly on carpeting, tile, or any combustible material other than wood ﬂooring.

J951X*U series gas furnaces can be installed horizontally (

Figure 11) in an attic, basement, crawl space or alcove. It

can also be suspended from a ceiling in a basement or utility room in either a right to left airﬂow or left to right airﬂow as shown in

These furnaces are shipped with the bottom panel installed. If the furnace is installed horizontally, remove the bottom panel from the furnace before attaching the duct system. See Bottom Panel Removal on

If installing the furnace with an evaporator coil (in an attic), it is required that a drip pan be placed under the furnace. If the installation is on a combustible platform as shown in

, it is recommended that the drip pan extend at least 12

inches past the top and front of the furnace.

NOTE: Although it is not required to use a drip pan for heat only applications, state and local codes may require it.

Figure 12 (page 15).

page 19.

Figure

Page 15

Figure 11. J951X*U Horizontal installation

Flue pipe vented

to outside

J-Trap Height 3” Min.

Coil Plenum

Wood or

non-combustible

platform

Two-pipe installation shown

Combustion Air

Condensate

Drain Lines

Concrete

“A”

“B”

Opening in concrete floor

on a Platform

Nuts (x2)

Lag Bolt

Threaded

Rod

Washer

and

Lockwasher

Nuts (x2)

Figure 12. J951X*U Horizontally Suspended

in an Attic

Floor

Furnace

Downﬂow Furnaces

WARNING:

The furnace must not be installed directly on carpeting, tile, or any combustible material other than wood ﬂooring.

WARNING:

Failure to install the downﬂow sub-base kit may result in ﬁre, property damage or personal injury.

To install an J951X*D series gas furnace on combustible ﬂooring, a special sub-base is required. Downﬂow sub-base kits are factory supplied accessories and are listed according to the cabinet letter of the furnace. Refer to the technical sales literature for part numbers. Please follow the instructions

provided with the kit.

A downﬂow sub-base kit is not necessary if the furnace is installed on a factory or site-built cased air conditioning coil. However, the plenum attached to the coil casing must be installed so that its surfaces are at least 1” from combustible construction.

Installation on a Concrete Slab

1. Create an opening in the ﬂoor according to the dimensions

Table 3.

2. Position the plenum and the furnace as shown in

Figure 13.

Inducer & Venting Options

To increase installation ﬂexibility, the inducer assembly can be rotated up to 3 different positions. Each variation has slightly different requirements with regard to condensate disposal and, in some cases, the need to seal the furnace cabinet.

IMPORTANT NOTE:

The Inducer Assembly must never be positioned to vent downwards on horizontal installs.

Figure 13. Furnace on a Concrete Slab

If suspending the furnace from the ceiling, assemble a support frame ( threaded rod. Fasten the frame together with nuts, washers, and lockwashers. Secure the support frame to the rafters with lag bolts. The furnace can also be suspended using steel straps around each end of the furnace. The straps should be attached to the furnace with sheet metal screws and to the rafters with bolts.

It is recommended for further reduction of ﬁre hazard that cement board or sheet metal be placed between the furnace and the combustible ﬂoor and extend 12 inches beyond the front of the door and top of the furnace.

Sheet

Metal

Plenum

Figure 12) using slotted iron channel and full

MODEL #

J951X054BD

J951X072CD

J951X090CD

NOTE: Dimensions shown in Inches.

DIM. “A” DIM. “B”

16 5/8 19 1/4

20 1/8 19 1/4

Table 3. Cutout Dimensions

Page 16

J951X*U & J951X*D SERIES - CONVENTIONAL (1 PIPE)

VENT

DIRECTION

Right Option 1 N/A N/A Option 9

Up N/A Option 5 Option 6 Option 10

Left Option 2 N/A N/A Option 11

J951X*U & J951X*D SERIES - DIRECT VENT (2-PIPE)

VENT

DIRECTION

Right Option 3 N/A N/A Option 12

Up N/A Option 7 Option 8 Option 13

Left Option 4 N/A N/A Option 14

UPFLOW

HORIZONTAL

RIGHT

HORIZONTAL

RIGHT

HORIZONTAL

LEFT

HORIZONTAL

LEFT

DOWNFLOW

Table 4. Vent & Inducer Blower Options

Before using Table 4, the number of pipes (1-pipe or 2-pipe) connected to the furnace must be known. Find the proper furnace style (upﬂow, horizontal, or downﬂow) and then the side that the pipes will exit from the furnace. Finally select the option that properly matches your installation type. For J951X*U series, see

. For J951X*D series, see Figure 36 (page 39).

38)

Figure 34 (page 37) & Figure 35 (page

NOTE: It is important that Direct Vent (2-pipe) systems maintain an airtight ﬂow path from the air inlet to the ﬂue gas outlet. The furnace ships from the factory with two holes in the cabinet for the air inlet and ﬂue gas outlet. In certain conﬁgurations, it is necessary to remove and relocate a plastic plug in the furnace cabinet. If changing the position of the air inlet and ﬂue gas outlet, it is required that the previous hole be closed off with the plastic plug to maintain air tightness in the furnace. The hole locations for all furnace series are shown in

Figure 29 and Figure 30.

Inducer Assembly Rotation

6. Remove the cabinet plug from side of furnace and reinstall

in hole on opposite side of cabinet.

7. Install in-line drain assembly and tubing.

8. Install all condensate drain lines. For J951X*U series,

see

Figure 34 (page 37) & Figure 35 (page 38). For

J951X*D series, see

Figure 36 (page 39).

9. Reconnect the electrical harness to the inducer assembly.

10. Reconnect the inducer assembly ground wire to the blower

deck or door.

11. Verify operation as detailed on the furnace label.

Pressure Switch Tubing

All upﬂow / horizontal furnaces have two switches, one connected to the static tap on the inducer assembly and the other to the collector box. of pressure switch tubing for J951X*U furnaces. Downﬂow (J951X*D) furnaces require only one switch connected to the inducer’s static tap as shown in

Figure 14 displays the proper routing

Figure 15.

WARNING:

Inducer rotation must be completed before the furnace is connected to gas and electric. If both utilities have been connected, follow the shutdown procedures printed on the furnace label and disconnect the electrical supply.

CAUTION:

It is good practice to label all wires prior to disconnection. Wiring errors can cause improper and dangerous operation.

1. Disconnect the electrical harness from the inducer assembly.

2. Remove the inducer assembly ground wire from the blower deck.

3. Remove 3 screws securing the inducer assembly to the header box.

4. Rotate the inducer assembly to its new position.

5. Secure the inducer assembly to the header box by reinstalling the three screws. If the inducer assembly is rotated to the left or right side of the furnace, use the extra screw provided in the parts package.

Figure 14. Pressure Switch Tubing for

Upﬂow Furnaces

Models J951X038U, J951X054U, J951X072U,

J951X090U, J951X108U, & J951X120U

Figure 15. Pressure Switch Tubing for

Downﬂow Furnaces

Models J951X054D, J951X072D, & J951X090D

Page 17

Alternate Pressure Switch Location

LOCATION

or Inlet

Grommet

ø 2 1/4” Rubber Grommet

In some inducer orientations, the inducer pressure switch may interfere with gas pipe installation. Determine the side of the cabinet the gas pipe will enter and see if the inducer pressure switch needs to be moved. If the pressure switch interferes with the gas pipe, use these instructions for relocating it to an alternate location:

1. Shut off any electrical power to the furnace.

2. Label and disconnect the tubing and wires from the pressure switch (

3. Remove two screws securing the pressure switch to the inducer housing.

4. Remove the pressure switch from the mounts on the inducer housing and relocate it to the other set of mounts 90° from previous location.

5. Secure the pressure switch with two screws.

6. Reconnect the tubes and wires to the pressure switch.

Figure 16).

PRIMARY

ALTERNATE

Accessories

The components below are included in the extra parts bag that is supplied with the purchase of your furnace. Depending on your particular installation, some of these components are optional and may not be used. Please refer to the descriptions and accompanying ﬁgures when installing these items. NOTE: Some parts may not be supplied with each furnace. Refer to the literature in the extra parts bag for the parts included with the particular furnace.

Finish Flange

The ﬁnish ﬂange must be installed to vent the combustion air pipe through the top of the furnace. NOTE: For proper installation it is important that the pipe and screw holes in the ﬁnish ﬂanges, gasket, and cabinet are aligned. See

1. Position ﬂange gasket over hole in the furnace cabinet.

2. Position finish flange on top of the flange gasket. NOTE: Make sure the ﬂange is properly oriented so that the FRONT lettering is located near the front of the furnace as shown in

3. Secure ﬂange and gasket to cabinet with three ﬁeld supplied sheet metal screws.

Rubber Grommets

The 2 1/4” rubber grommet is used to seal the opening between the furnace cabinet and the 2” PVC vent pipe. The rubber grommet should be installed in the 3” hole prior to running the vent pipe out of cabinet. No sealants are required. See

Figure 18.

The 7/8” rubber grommet is used to seal the opening between the furnace cabinet and the gas pipe. The rubber grommet should be installed in the 1 5/8” hole prior to running the gas pipe into the cabinet. No sealants are required.

The 3/4” rubber grommet is used if venting out the left side of the cabinet and the drain tube is routed through the blower deck. Remove the plastic plug from the hole and install the grommet before routing the drain tube.

Figure 17.

Figure 16. Alternate Pressure Switch Location

FRONT

FRONT lettering must be

located near front

of furnace

Hole for

Flue

Vent Pipe

Finish

Flange

Flange Gasket

Hole f Air Vent Pipe

Figure 17. Finish Flange

(see note)

Ø 3/4” Rubber

Figure 18. Rubber Grommets

ø 7/8” Rubber

Grommet

Page 18

PVC Components

INSTALLATION OF PVC COMPONENTS

ubing (Field Supplied)

(Do Not Trap)

IMPORTANT NOTES:

• Before permanently installing these components, it is

recommended you dry-ﬁt them ﬁrst to ensure proper ﬁt and alignment with other vent pipes.

• The 2” PVC components shown in

Figure 19 are not

provided in the extra parts bag for *SC & *SL models. However the PVC Trap (P/N 664659) can be purchased thru your local distributor.

The 2” PVC tee, reducer, PVC Trap and 1/2” X 1/2” hose barb are used when the inducer is rotated to vent out thru the left or right side of the furnace cabinet. See

Figure 19.

The 1/2” X 3/4” hose barb can be used to route the condensate drain to the outside of the cabinet. It must be installed from inside the cabinet with the threaded end inserted thru the 1 1/16” hole. The condensate drain should be connected to the barbed end. Attach 1” PVC drain line to the threaded end. See

Figure 29 (page 29) or Figure 30 (page 29) for

hole location.

Typical Orientation

1. Install the PVC Tee vertically on the 2” vent pipe that is extending out the side of the cabinet. Permanently bond them together using appropriate primer and cement. Refer to the typical orientation shown in

2. Install the reducer or PVC trap (if supplied) on the bottom end of the PVC Tee. Permanently bond them together using appropriate primer and cement.

3. Install the 1/2” x 1/2” hose barb on the 2” PVC reducer. NOTE: Do not over tighten! Use an adequate amount of Teﬂon tape on the threads. Do not use liquid sealants.

4. Verify all connections and joints for tight ﬁt and proper alignment with other vent pipes.

Figure 19.

(TYPICAL ORIENTATION)

2” PVC Pipe from Inline

Drain Assembly

(Not Included)

2” PVC Tee

PVC TRAP

Not Included in

*SC & *SL Models

1/2” T

1/2” x 3/4”

Hose Barb

INSTALLATION OF PVC COMPONENTS

(ALTERNATE ORIENTATION)

2” PVC Pipe from Inline

Drain Assembly

(Not Included)

2” PVC Tee

1/2” x 3/4”

Hose Barb

Drain Line Attached

to PVC Trap

(Do Not Trap)

2” PVC Elbow

(Field Supplied)

PVC TRAP

Not Included in

*SC & *SL Models

1/2” Tubing (Field Supplied)

Drain Line Attached

to PVC Trap

Figure 19. PVC Components

2” x 3” PVC Coupling

Alternate Orientation

1. Install the 2” PVC Tee horizontally on the 2” vent pipe that is extending out the side of the cabinet. Permanently bond them together using appropriate primer and cement. Refer to the alternate orientation shown in

2. Install the 2” PVC Elbow on the end of the 2” PVC Tee. Permanently bond them together using appropriate primer and cement.

3. Install the reducer or PVC trap (if supplied) on the bottom end of the PVC Tee. Permanenly bond them together using appropriate primer and cement.

4. Install the 1/2” x 1/2” hose barb on the 2” PVC reducer. NOTE: Do not over tighten! Use an adequate amount of Teﬂon tape on the threads. Do not use liquid sealants.

5. Verify all connections and joints for tight ﬁt and proper alignment with other vent pipes.

Optional PVC Pipe Installation

When running the 2” PVC pipe out through the top of the J951X*U upﬂow furnace, there may be possible clearance issues when transitioning the PVC pipe from 2” to 3”:

• If the size of the PVC ﬂue needs to be increased from 2”

to 3”, two, 2” x 45° PVC elbows may be used to achieve the clearances needed between the coil box and the 2” x 3” coupling. See

• Install the 2” x 3” coupling in the vertical run only. If the

coupling is installed horizontally, it will allow water to build up inside the furnace and cause a lock out condition.

• To avoid the clearance issue, it is recommended that the

furnace be vented through the left side or the right side of the cabinet.

Figure 20.

Figure 19.

Coil Box

2” x 450 PVC Elbow

2” PVC Pipe

Figure 20. Optional PVC Pipe Installation

Condensate Drain Lines

If the furnace is installed in an area where temperatures fall below freezing, special precautions must be made for insulating condensate drain lines that drain to the outdoors. If condensate freezes in the lines, this will cause improper operation or damage to the furnace. It is recommended that all drain lines on the outside of the residence be wrapped with an industry approved insulation or material allowed by local code.

• The method for disposing condensate varies according to local codes. Consult your local code or authority having jurisdiction.

• The condensate drain line must be trapped using a kit (P/N- 922485) or ﬁeld supplied parts. After the drain trap, condensate can continue to the drain by connecting to a recommended 3/4” ID minimum drain line, but no smaller

Page 19

than the original tubing ID supplied by the manufacturer.

Screws

The drain line should slope downward away from the furnace to ensure proper drainage.

• The placement of the condensate drain lines will depend on the conﬁguration selected in

Table 4 (page 16). The

drain lines can be routed out the left or right side of the furnace, but must maintain a downward slope to ensure proper condensate drainage. The J-trap may need to be rotated to the side that matches your setup.

For J951X*U series, see

35 (page 38)

. To rotate the J-trap, loosen the clamp on the drain

39)

. For J951X*D series, see Figure 36 (page

Figure 34 (page 37) & Figure

tube, rotate the J-trap to either side, and retighten the clamp.

• It is permissible to locate the trap away from the furnace. The condensate drain system (J-trap and drain tube) should be no more than 30 equivalent feet while maintaining 1/4” per foot slope, and insulated if located in an unconditioned space.

THREE GENERAL PRINCIPLES APPLY:

• Each condensate drain must be trapped separately using a J-Trap or ﬁeld supplied loop. After individually trapping the condensate lines, it is acceptable to combine the drains.

• There must always be a drain attached to the collector at the outlet of the secondary heat exchanger.

• There must always be a drain at the lowest point of the venting system. NOTE: If using a condensate pump, the furnace drain line must be installed above the pumps water line.

EXCEPTIONS & CLARIFICATIONS TO THE

GENERAL RULES:

• If the vent exits the furnace horizontally, the vent may be turned vertically with a tee. The drip leg formed by the tee must include a drain. (Option 1, Option 3, Option 4, Option 11, Option 12, & Option 14)

• In certain cases, it is permitted to drain the inducer back into the top drain of the collector. This drain must not sag in the middle. (Option 1, Option 3, Option 5, Option 7, Option 9, Option 10, Option 12, & Option 13)

Bottom Panel Removal

The steps listed below describe how to remove the bottom panel from the furnace. See

1. Remove the door from the blower compartment.

2. Disconnect the wires from the blower motor plug.

3. Remove two screws securing the blower assembly to the

furnace.

4. Carefully pull the blower assembly out thru the front of the

furnace.

5. Remove all screws securing bottom panel to bottom of

furnace and front brace.

6. Lift up and slide bottom panel out through front of furnace.

7. Reinstall the blower assembly in reverse order.

Figure 21.

Door

Screws

Blower

Plug

Screws

Blower

Assembly

Bottom

Panel

Figure 21. Bottom Panel Removal

Screws

Door

Bottom

Panel

Blower

Deck

Front

Brace

Figure 22. Alternate Removal Method

Alternate Bottom Panel Removal

If the bottom panel cannot be removed using the previous instructions, the steps below are an alternate method for removing the bottom panel. See

1. Remove the door from the blower compartment .

2. Remove all screws securing the bottom panel to the front brace.

3. Remove two screws securing the furnace cabinet to the blower deck.

4. Remove all screws securing the furnace cabinet to the bottom panel.

5. Remove the screw securing the bottom corner of the furnace cabinet to the front brace.

6. Carefully spread the bottom corner of the furnace cabinet outwards while sliding the bottom panel out through the front of the furnace.

7. Reassemble the furnace in reverse order.

Figure 22.

Page 20

GAS SUPPLY & PIPING

WARNING:

FIRE OR EXPLOSION HAZARD

• Failure to follow safety warnings exactly could result in serious injury, death or property damage.

• Installation and service must be performed by a qualiﬁed installer, service agency or the gas supplier.

• Do not store or use gasoline or other ﬂammable vapors and liquids in the vicinity

of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not use any phone in your building.

• Leave the building immediately.

• Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.

• If you cannot reach your gas supplier, call the ﬁre department.

• All gas piping must be installed in compliance with local codes and utility regulations. In the absence of local codes the gas line installation must comply with the latest edition of the National Fuel Gas Code (ANSI Z223.1) or (CAN/CSA B149.1) Installation Codes.

• Some local regulations require the installation of a manual main shut-off valve and ground joint union external to the furnace as shown in &

Figure 24 (page 21). The shut-off valve should be

readily accessible for service and/or emergency use. Consult the local utility or gas supplier for additional requirements regarding placement of the manual main gas shut-off.

• Per ANSI 21.47, A 1/8-inch NPT plugged tapping, accessible for test gauge connection, must be installed immediately upstream of the gas supply connection to the furnace external to the cabinet. If local codes allow the use of a ﬂexible gas appliance connector, always use a new listed connector. Do not use a connector that has previously serviced another gas appliance.

• Gas piping must never run in or through air ducts, chimneys, gas vents, or elevator shafts.

• Compounds used on threaded joints of gas piping must be resistant to the actions of LP propane gas.

• The main gas valve and main power disconnect to the furnace must be properly labeled by the installer in case emergency shutdown is required.

• Flexible gas connectors are not recommended for this type of furnace but may be used if allowed by local jurisdiction. Only new ﬂexible connectors may be used. Do not use a connector which has previously serviced another gas appliance.

• A drip leg should be installed in the vertical pipe run to the unit. See

Figure 23 or Figure 24.

Figure 23 (page 21)

Table 6 (page 32) lists gas ﬂow capacities for standard pipe

sizes as a function of length in typical applications based on nominal pressure drop in the line.

The furnace may be installed with either left or right side gas entry. When connecting the gas supply, provide clearance between the gas supply line and the entry hole in the furnace casing to avoid unwanted noise and/or damage to the furnace. Typical gas hookups are shown in

Figure 23 & Figure 24.

Leak Check

WARNING:

FIRE OR EXPLOSION HAZARD Failure to follow safety warnings exactly could result in serious injury, death or property damage.

Never test for gas leaks with an open ﬂame. Use a commercially available soap solution made speciﬁcally for the detection of leaks to check all connections. A ﬁre or explosion may result causing property damage, personal injury or loss of life.

After the gas piping to the furnace is complete, all connections must be tested for gas leaks. This includes pipe connections at the main gas valve, emergency shutoff valve and ﬂexible gas connectors (if applicable). The soap and water solution can be applied on each joint or union using a small paintbrush. If any bubbling is observed, the connection is not sealed adequately and must be retightened. Repeat the tightening and soap check process until bubbling ceases.

IMPORTANT NOTE:

When pressure testing gas supply lines at pressures greater than 1/2 psig (14 inch W.C.), the gas supply piping system must be disconnected from the furnace to prevent damage to the gas control valve. If the test pressure is less than or equal to 1/2 psig (14 inch W.C.), close the manual shut-off valve.

High Altitude Application (Natural Gas Only)

High altitude conversion with this furnace depends on the installation altitude and the heating value of the gas. Installation of this furnace at altitudes above 2,000 feet shall be in accordance with local codes, or in the absence of local codes, the National Fuel Gas Code, ANSI Z223.1/ NFPA 54 or National Standard of Canada, Natural Gas & Propane Installation Code CSA B149.1. Please consult your local code authority.

WARNING:

The reduction of input rating necessary for high altitude installation may only be accomplished with factory supplied oriﬁces. Do not attempt to drill out oriﬁces in the ﬁeld. Improperly drilled orifices may cause fire, explosion, carbon monoxide poisoning, personal injury or death.

Page 21

J951X*U SERIES

Manifold

Drip Leg

Shut-Off

Valve

Ground

Joint

Union

J951X*D SERIES

NOTE B: Inducer assembly omitted for clarity of pipe installatio

Shut-Off

Burner

Assembly

Manifold

Burner

Assembly

Valve

ip Leg

Note “A”

Ground

Joint

Union

See

Gas

Valve

See

Note “B”

Elbow

Left Side Entry

Pipe

Nipple

Plug

Gas

Valve

Pipe

Nipple

See

Note “B”

Right Side Entry

Figure 23. Typical Gas Connections - Upﬂow Models

See

Note “A”

Elbow

Valve

ip Leg

Ground

Joint

Union

See

Note “A”

Manifold

Elbow

Plug

See

Note “B”

Left Side Entry

NOTE A: Consult local codes for Shut-Off Valve location requirements

Pipe

Nipple

Gas

Valve

Burner

Assembly

Note “B”

Gas

Valve

Figure 24. Typical Gas Connections - Downﬂow Models

Elbow

See

Right Side Entry

Pipe

Nipple

See

Note “A”

Shut-Off

Valve

Drip Le

Ground

Joint

Union

Manifold

Page 22

The furnaces are shipped from the factory with oriﬁces and gas regulator settings for natural gas operation at sea level altitudes. At 2,000 feet, the NFGC requires that this appliance be derated 4% for each 1,000 feet of altitude.

For example, the input needs to be reduced 8% at 2,000 feet, 12% at 3,000 feet, etc. This deration is in reference to the input rate and gas heating value at sea level.

To derate the furnace requires knowing the heating value of the gas at the installation site. Heating values at particular job sites vary for two reasons:

1. The chemical mixture of the gas varies across regions and is expressed as the “sea level heating value”.

2. The heating value varies by altitude. For this reason, especially in high altitude areas, the local gas utility speciﬁes the heating value at the residence’s gas meter as the “local value”.

For added ﬂexibility, two tables have been provided for natural gas installations with high or low heating values at sea level.

Table 10 & Table 11 (page 34) contain the manifold pressure

and oriﬁce sizes to use at various altitudes. for natural gas installations with a heating value of more than 1,000 Btu per cubic foot and 1,000 Btu per cubic foot. To determine which table to use:

1. Consult the local utility for the local heating value at your installation site.

2. From

3. If your sea level heating value is HIGH, use

After changing the regulator pressure or the oriﬁces, it is required that you measure the gas input rate. This may be accomplished in the usual way, by clocking the gas meter and using the local gas heating value. See Verifying and Adjusting the Input Rate section on

Table 9 (page 33), ﬁnd your local heating value as

supplied by the utility company. Follow down the column and stop at your altitude level.

it’s LOW, use

Elevation: ......................................................5,000 feet

Type of Gas: .............................................. Natural Gas

Local Heating Value of Gas: .................................. 750

From

Table 9, ﬁnd 750 and follow down the column, stop

at the 5,000 feet row. The heating value listed is LOW.

Table 11 will be used to determine oriﬁce size and manifold

pressure.

Table 11. See Example below.

Table 11 (LOW) is for less than

EXAMPLE

Table 10 (HIGH) is

Table 10 or if

page 25.

IMPORTANT NOTE:

Observe the action of the burners to make sure there is no yellowing, lifting or ﬂashback of the ﬂame.

For US installations only: To avoid nuisance tripping

at altitudes from 7500 to 10,000 feet, a pressure switch conversion may be required. Consult the tables in the LP and High altitude and LP gas conversion kit for installations

in the US.

Converting from Natural Gas to LP / Propane

WARNING:

The furnace was shipped from the factory equipped to operate on natural gas. Conversion to LP / Propane gas must be performed by qualiﬁed service personnel using a factory supplied conversion kit. Failure to use the proper conversion kit can cause ﬁre, explosion, property damage, carbon monoxide poisoning, personal injury, or death.

Conversion to LP / Propane is detailed in the installation instructions provided with the conversion kit. Generally, this will require the replacement of the burner oriﬁces and the spring found under the cap screw on the pressure regulator. Approved conversion kits are listed below:

• Installations in the United States: For Propane (LP) conversion or for LP gas installations in altitudes between 2,000 ft. and 10,000 ft. above sea level, use the LP & High Altitude LP Gas Conversion Kit (P/N 905028) for Installations in the United States. Please follow the instructions provided with the kit.

• Installations in Canada: For Propane (LP) conversion or for LP Gas installations in altitudes between zero and 4,500 ft. above sea level, use the LP & High Altitude LP Gas Conversion Kit (P/N 905029) for Installations in Canada. Please follow the instructions provided with

the kit.

If the installation is in the U.S. and above 2,000 ft., refer to

Table 8 (page 33) to determine the correct oriﬁce size and

regulator pressure. See

EXAMPLE

Elevation: ......................................................5,000 feet

Type of Gas: ............................................ Propane Gas

Input BTUH of Furnace: ....................................72,000

From

Table 8, ﬁnd 5,000 and follow across the row, stop

at the 72,000 btu column. The manifold pressure listed is 10.0 and the oriﬁce size is 57.

When conversion is complete, verify the manifold pressure and input rate are correct as listed in the table.

Example below.

Page 23

ELECTRICAL WIRING

WARNING:

ELECTRICAL SHOCK, FIRE OR

EXPLOSION HAZARD Failure to follow safety warnings exactly could result in serious injury, death or property damage.

Improper servicing could result in dangerous operation, serious injury, death or property damage.

• Before servicing, disconnect all electrical

power to furnace.

• When servicing controls, label all wires prior

to disconnecting. Reconnect wires correctly.

• Verify proper operation after servicing.

• Electrical connections must be in compliance with all applicable local codes with the current revision of the National Electric Code (ANSI/NFPA 70).

• For Canadian installations the electrical connections and grounding shall comply with the current Canadian Electrical Code (CSA C22.1 and/or local codes).

IMPORTANT NOTE:

If replacing any of the original wires supplied with the furnace, the replacement wire must be copper wiring and have a temperature rating of at least 105° F (40° C). For electrical speciﬁcations, refer to the furnace nameplate or

Table 5 (page 23).

Line Voltage Wiring

It is recommended that the line voltage (115 VAC) to the furnace be supplied from a dedicated branch circuit containing the correct fuse or circuit breaker for the furnace as listed in

Table 5 (page 23).

The installer should become familiar with the units wiring diagram before making any electrical connections to the unit. See

Figure 31 (page 30), Figure 32 (page 31), or

the unit wiring label.

IMPORTANT NOTES:

An electrical disconnect must be installed readily accessible from and located within sight of the furnace. See

Figure 25 (page 24) or the wiring diagram label inside

of the control door. Any other wiring methods must be acceptable to authority having jurisdiction.

Proper line voltage polarity must be maintained in order for the control system to operate correctly. Verify the incoming neutral line is connected to the white wire and the incoming HOT line is connected to the black wire. The furnace will not operate unless the polarity and ground are properly connected as shown in

Figure 25.

Grounding

WARNING:

To minimize personal injury, the furnace cabinet must have an uninterrupted or unbroken electrical ground. The controls used in this furnace require an earth ground to operate properly. Acceptable methods include electrical wire or conduit approved for ground service. Do not use gas piping as an electrical ground!

FURNACE

MODEL

NUMBER

J951X038BU

J951X054BU

J951X072CU

J951X090CU

J951X108DU

J951X120DU

J951X054BD

J951X072CD

J951X090CD

THERMOSTAT WIRE GAUGE

FURNACE

INPUT

(BTUH)

38,000 17 ½ 115-60-1 127 103 9.3 54,000 17 ½ 115-60-1 127 103 9.3 72,000 21 115-60-1 127 103 9.3

85,000 21 115-60-1 127 103 12.0 108,000 24 ½ 115-60-1 127 103 12.0 115,000 24 ½ 115-60-1 127 103 12.0

54,000 17 ½ 115-60-1 127 103 9.3

72,000 21 115-60-1 127 103 9.3

90,000 21 115-60-1 127 103 12.0

24 55 ft. 25 ft. 22 90 ft. 45 ft. 20 140 ft. 70 ft. 18 225 ft. 110 ft.

CABINET

WIDTH

(IN.)

NOMINAL

ELECTRICAL

SUPPLY

MAXIMUM

OPERATING

VOLTAGE

RECOMMENDED THERMOSTAT WIRE LENGTH

2 - WIRE

(HEATING)

MINIMUM

OPERATING

VOLTAGE

MAXIMUM FURNACE

AMPERES

4 OR 5 WIRE

(COOLING)

Table 5. Wire Length & Voltage Speciﬁcations

Page 24

Field Supplied

Field Line Voltage Wiring

NOTE: Connections made within the furnace burner compartment do not require a junction box.

A/C

For

ELECTRONIC AIR CLEANER

HUMIDIFIER TAP

Factory Line Voltage Wiring

Fused Service

Panel

Disconnect within

Sight of Furnace

Field Supplied

Panel Connector

Black (Hot)

White (Neutral)

Green or Bare (Ground)

Ground

Junction Box (may be int. or ext. to the furnace). These connections can be made in the field supplied disconnect at the furnac

Figure 25. Line Voltage Field Wiring

Thermostat / Low Voltage Connections

• The furnace is designed to be controlled by a 24 VAC thermostat. The thermostat’s wiring must comply with the current provisions of the NEC (ANSI/NFPA 70) and with applicable local codes having jurisdiction.

• The thermostat must be installed according to the instructions supplied by the thermostat manufacturer. Low voltage connections (24 VAC) from the thermostat are wired to the terminal strip on the integrated control in the furnace.

Figure 26 contains the proper connections

for heating only (two-wire) and heating/cooling (four-wire) applications. Recommended minimum wire gauge for thermostat wiring is shown in

Table 5 (page 23).

• The thermostat should be mounted about 5 feet above the ﬂoor on an inside wall. DO NOT install the thermostat on an outside wall or any other location where its operation may be adversely affected by radiant heat from ﬁreplaces, sunlight, or lighting ﬁxtures, and convective heat from warm air registers or electrical appliances. Refer to the thermostat manufacturer’s instruction sheet for detailed mounting information.

Twinning

WARNING:

When servicing either twinned furnace, power must be turned off on both furnaces. Failure to comply may result in improper operation leading to damage to the furnaces or personal injury!

Single stage furnaces are not supplied with a built-in twinning capability. Other valuable features and enhancements were made to the new control that made it necessary to remove the twinning capability. For twinning of single stage furnaces with PSC motors, a twinning kit is available for purchase. Refer to the technical sales literature for part numbers. Please

follow the instructions provided with the kit.

Single stage furnaces are equipped with a ﬁxed speed blower; therefore, the twin terminal on the blower control boards (

Figure 27 (page 25)) may be used to twin the single stage

furnaces. The twinning system requires a relay (P/N 624843) in the secondary furnace for proper twinning.

For proper twinning of ﬁxed speed furnaces the following criteria must be met:

• Both furnaces and motors must be the same size.

• Both motors must be on the same speed for cooling and heating.

COOL

HEAT

XFMR

SPEED

SELECT

FLAME

BLOWER

DELAY

EAC

Black

White

Ground

STATUS

OFF

HIGH

JUMPER PIN

SETUP

RED GREEN YELLOW

180 120

90 60

LOW

120

MOTOR SPEED TAPS

180

Black

White

Connect

R & W

Heating

Only

NOTE: The “Y” terminal

on the control board must be connected to the thermostat for proper cooling mode operation.

FIELD WIRING

LOW VOLTAGE CONNECTION

Ground

CONDENSING

ROOM

THERMOSTAT

R C Y G W

NEUTRAL LEADS

UNIT

Black

White

3 AMP FUSE

6 3 5

RCYGW

NEUTRALS

CONDENSING UNIT

CONTROL BOX

COM

FAN

24V

HUM

Figure 26. Low Voltage Field, Four-wire

Heating/Cooling Applications

• Both furnaces must have a common return duct and common supply plenum.

• Both furnaces must be the same phase and on the same leg of power.

• Furnaces equipped with variable speed iSEER™

motors may not be twinned under any circumstances.

For twinning of single stage furnaces equipped with ﬁxed speed blowers, refer to Figure 27 and the following instructions:

1. Turn off all power to both furnaces.

2. Attach a wire between the two twin terminals on the blower

control boards. Use ﬁeld supplied wire and 3/16” wire terminals.

NOTE: One furnace can be used for one stage of heating and the other furnace can be used for the second stage of heating. The installer also has the choice of running one furnace only or both furnaces. In both cases the blowers will run at the same time and at the same speeds:

One stage heating

• Connect the thermostat wires to the primary furnace control board. Mount the relay on the bracket on the secondary furnace.

• Connect W from the primary furnace to the coil side of the relay (using ﬁeld supplied wire and 3/16” terminals).

Page 25

PRIMARY FURNACE

SECONDARY FURNACE

SINGLE STAGE HEATING (WITH TWINNING)

UNIT

6-Pin Wiring

Harness

UNIT

6-Pin Wiring

Harness

THERMOSTAT

TWIN TERMINAL

PRIMARY FURNACE

TWO STAGE HEATING (WITH TWINNING)

THERMOSTAT

TWIN TERMINAL

GYR

GYC

FURNACE

Port

BOARD

Expansion

BLOWER

CONTROL

BOARD

Port

Expansion

GYR

GYC

FURNACE

BOARD

Port

Expansion

BLOWER

CONTROL

BOARD

Port

Expansion

6-Pin Wiring

Harness

SECONDARY FURNA

6-Pin Wiring

Harness

RELAY

COM

WHITE

RED

FURNACE

Port

BOARD

Expansion

BLOWER

CONTROL

BOARD

Port

Expansion

TWIN TERMINAL

RELAY

COM

WHITE

RED

FURNACE

BOARD

Port

Expansion

BLOWER

CONTROL

BOARD

Port

Expansion

TWIN TERMINAL

GYCR

Figure 27. Single & Two Stage Twinning

• Connect C from the primary furnace to the coil side of the relay (using ﬁeld supplied wire and 3/16” terminals). NOTE: Make sure connections are made on opposite sides of the coil.

• Connect R from the secondary furnace control board to the COM side of the relay (use included red wire).

• Connect W from the secondary furnace control board to NO side of the relay (use included white wire).

Two stage heating

• Connect the thermostat wires to the furnace control board (except W2). Mount the relay on the bracket on the secondary furnace.

• Connect W1 from the thermostat control to W of the primary furnace.

• Connect W2 from the thermostat to the coil side of the relay (using ﬁeld supplied wire and 3/16” terminals)

• Connect C from the primary furnace to the coil side of the relay (using ﬁeld supplied wire and 3/16” terminals).

NOTE: Make sure connections are made on opposite

sides of the coil

• Connect R from the secondary furnace control board to the COM side of the relay (use included red wire).

• Connect W from the secondary furnace control board to

NO side of the relay (use included white wire).

Heat Anticipator

Set the heat anticipator according to the instructions supplied by the thermostat manufacturer. To determine the heat anticipator setting:

1. Add the current draw of the system components; or

2. Measure the current ﬂow on the thermostat R-W circuit

after the circulating blower motor has started.

START-UP & ADJUSTMENTS

Pre-Start Check List

√ Verify the polarity of the connections are correct, the line

voltage power leads are securely connected and the furnace is properly grounded.

√ Verify the thermostat wires (R, W, Y, & G) are securely

connected to the correct leads on the terminal strip of the circuit board.

√ Verify the jumper setting (for fan speed) on the control

board. To select fan speed, see jumper on the control board.

√ Verify the gas line service pressure does not exceed 10.0

inches of W.C., and is not less than 4.5 inches W.C. for natural gas. For LP gas the line service pressure must not exceed 14 in. W.C., and must not be less than 11.0 in. W.C.

√ Verify the roll-out and manual reset switch is closed. If

necessary, press the red button to reset a switch. DO NOT install a jumper wire across a switch to defeat its function. If a switch reopens on startup, DO NOT reset the switch without identifying and correcting the fault condition.

√ Verify the blower door is in place, closing the door switch

in the line voltage circuit.

√ Verify the gas line has been purged and all connections

are leak free.

Start-up Procedures

Do not perform these steps until all of the checks in the previous steps have been completed:

1. Set the thermostat to the lowest setting.

2. Turn off all electrical power to the furnace.

3. Follow the Operating Instructions on the label attached to the furnace.

4. Set the thermostat above room temperature and verify the Operating Sequence (

page 27).

5. After 5 minutes of operation, set the thermostat below room temperature and verify steps 9 - 10 of the Operating Sequence.

Verifying & Adjusting Input Rate

The input rate must be veriﬁed for each installation to prevent over-ﬁring of the furnace. NOTE: The input rate must not exceed the rate shown on the furnace rating plate. At altitudes above 2,000 feet, it must not exceed that on the rating plate less 4% for each 1,000 feet. To determine the exact input rate, perform the following procedures:

1. Shut off all other gas ﬁred appliances.

2. Start the furnace and run it for at least 3 minutes.

3. Measure the time (in seconds) required for the gas meter to complete one revolution.

4. Convert the time per revolution to cubic feet of gas per hour using

5. Multiply the gas ﬂow rate in cubic ft per hr by the heating value of the gas in Btu per cubic ft to obtain the input rate in Btuh. See example.

• Time for 1 revolution of a gas meter with a 1 cubic ft dial = 40 seconds.

• From

• Local heating value of the gas (obtained from gas supplier) = 1,040 Btu per cubic ft.

• Input rate = 1,040 x 90 = 93,600 Btuh.

Table 6 (page 32).

EXAMPLE:

Table 6 read 90 cubic ft gas per hr.

Figure 26 and set the

Page 26

Capscrew

from the factory pre-wired for 4 blower speeds. There is a ﬁfth alternate speed available on the motor. To utilize the alternate speed, remove the wire at the motor plug of the desired speed to be changed (H, MH, ML, L). Reconnect this wire to the alternate motor plug speed tap.

Verifying Burner Operation

CAUTION:

Figure 28. Regulator Capscrew

6. The manifold pressure must be set to the appropriate value for each installation by a qualiﬁed installer, service agency or the gas supplier.

WARNING:

Do not attempt to drill the gas oriﬁces. Use only factory supplied oriﬁces. Improperly drilled orifices may cause fire, explosion, carbon monoxide poisoning, personal injury or death.

a.) Obtain the manifold pressure setting required for

this installation by referring to Propane or

for Natural Gas.

34)

b.) Remove the regulator capscrew (

INLET side of the regulator.

c.) Slowly turn the adjustment screw inside the regulator

to obtain the appropriate manifold pressure.

NOTE: Turning the screw clockwise increases the

pressure and turning the screw counter-clockwise decreases the pressure. To prevent backing the screw all the way out from the valve, turn the screw slowly.

d.) Replace and tighten the regulator capscrew over the

adjustment screw.

Table 10 (page 34) or Table 11 (page

Verifying & Adjusting Temperature Rise

After installation of the furnace, conﬁrm the temperature rise of the furnace is within the limits speciﬁed on the rating plate. Any temperature rise outside the speciﬁed limits could result in premature failure of the heat exchanger.

1. Place thermometers in the return and supply air stream as close to the furnace as possible. The thermometer on the supply air side must be shielded from direct radiation from the heat exchanger to avoid false readings.

2. Adjust all registers and duct dampers to the desired position and run the furnace for 10 to 15 minutes before taking any temperature readings. The temperature rise is the difference between the supply and return air temperatures.

For typical duct systems, the temperature rise will fall within the limits speciﬁed on the rating plate with the blower speed at the factory recommended setting. If the measured temperature rise is outside the speciﬁed limits, it may be necessary to change the speed of the blower.

NOTE: Lowering the blower speed will increase the temperature rise and a higher blower speed will decrease the temperature rise.

The furnace is equipped with a 5-speed ECM motor. Heating and cooling speed selection is made by moving the switch on the integrated control inside of the furnace. The furnace is shipped

Table 8 (page 33) for

Figure 28) from the

The door over the burners may only be open for inspection purposes only. The door must be installed during unattended operation.

1. Remove the burner compartment door.

2. Set the thermostat above room temperature and observe the ignition sequence. NOTE: The burner ﬂame should carry over immediately between all burners without lifting off, curling, or ﬂoating. The ﬂames should be blue, without yellow tips.

3. After validating the ﬂame, change thermostat setting to below room temperature.

4. Verify the burner ﬂame is completely extinguished.

5. Replace the burner compartment door.

Verifying Operation of the Supply Air Limit Switch

NOTE: A properly functioning limit switch should turn off

the gas valve when the return is blocked (time depends on how well the return air is blocked). The circulating air and combustion blowers should continue to run when the limit switch opens.

1. Verify the blower door is securely mounted in place and that there is power to the furnace.

2. Block the return airﬂow to the furnace by installing a closeoff plate in place of or upstream of the ﬁlter(s).

3. Set the thermostat above room temperature and observe the Operating Sequence.

4. Remove the close-off immediately after the limit switch opens. If the furnace continues to operate with no return air, set the thermostat below room temperature, shut off power to the furnace, and replace the limit switch.

System Operation

(Gas) Heating Mode

When the thermostat calls for heating, the circuit between R and W is completed. The furnace control board initiates the ignition sequence. Approximately 30 seconds after the gas ﬂame has proven, the blower motor will start. The blower will continue to operate after the call for heat has been removed for a selectable (switch on furnace control board) number of seconds. NOTE: All on- and off-delays for heating continue to be controlled by the furnace control board.

Cooling Mode

When the thermostat calls for cooling or heat pump heating, the circuit between R, G, and Y (O is ignored by the blower) is completed. The blower runs at the selected cooling motor torque.

Manual Fan

Select the speed using the jumper on the control board.

Page 27

Fault Conditions

There is a green and a red LED (labeled “Status”) on the motor control board to provide system faults as described below. Refer to control board fault conditions.

Table 14 (page 40) to determine motor

OPERATING SEQUENCE

The operating sequences for the heating, cooling, and fan modes are described below. Refer to the ﬁeld and furnace wiring diagrams:

Figure 31 (page 30)

Heating Cycle

1. The thermostat calls for heat by energizing the W terminal with 24VAC.

2. The control veriﬁes the pressure switch is open.

3. If the pressure switch is open, the control energizes the inducer and waits for the pressure switch to close. The pressure switch must close within 10 seconds.

4. The control runs the inducer for a 30 second pre-purge.

5. The control energizes the Hot Surface Igniter (HSI) output for the appropriate warm-up time limit.

6. The control energizes the main gas valve for 3 seconds.

7. If the ﬂame proved and ignites the gas, the control deenergizes the HSI. The gas valve and inducer remains energized. The control goes to blower on delay.

8. If ﬂame is present, the control energizes the blower on the selected HEAT speed 30 seconds after the gas valve opened. The gas valve and inducer remain energized.

9. When the thermostat demand for heat is satisﬁed, the control de-energizes the gas valve. The Inducer output remains on for a 30 second post-purge period.

10. Blower off timing begins when the thermostat is satisﬁed.

The control will operate at the selected HEAT speed of 60, 90, 120, or 180 seconds. If the blower off delay jumper is not present, the fan should still operate for 120 seconds at the selected HEAT speed. The Indoor blower motor is de-energized after a blower off delay as selected by the movable jumper.

Cooling Cycle

1. The thermostat calls for cooling by energizing the Y terminal with 24VAC.

2. The control energizes the blower in cooling speed and sends 24VAC to the contactor in the condensing unit

3. When the thermostat removes the call for cooling, the contactor in the outdoor condensing unit is de-energized and the control continues to run the fan for a period of 60 seconds.

Fan Mode

• When the thermostat energizes the G terminal for

continuous fan (without calling for heat or cooling), the indoor fan is energized on the selected FAN speed. See

Figure 26 (page 24) for fan speed settings.

• If a call for cooling occurs during continuous fan, the

blower will switch over to the selected COOL speed.

• If the W terminal receives a call for heat during continuous

fan, the blower will de energize.

• A call for fan is ignored while in lockout.

Figure 25 (page 24), Figure 26 (page 24),

and Figure 32 (page 31).

MAINTENANCE

WARNING:

ELECTRICAL SHOCK, FIRE OR

EXPLOSION HAZARD Failure to follow safety warnings exactly could result in serious injury, death or property damage.

Improper servicing could result in dangerous operation, serious injury, death or property damage.

• Before servicing, disconnect all electrical

power to furnace.

• When servicing controls, label all wires prior

to disconnecting. Reconnect wires correctly.

• Verify proper operation after servicing.

• Proper maintenance is most important to achieve the best performance from a furnace. Follow these instructions for years of safe, trouble free operation.

• These maintenance instructions are primarily intended to assist qualiﬁed technicians experienced in the proper maintenance and operation of this appliance.

• Always reinstall the doors on the furnace after servicing.

Do not operate the furnace without all doors and covers in place.

• Verify the thermostat is properly installed and will not be affected by drafts or heat from lamps or other appliances.

• To achieve the best performance and minimize equipment failure it is recommended that a yearly maintenance checkup be performed. At a minimum, this check should include the following items:

Air Filter(s) - Air ﬁlter(s) are not supplied with the furnace as shipped from the factory. The installer must provide a high velocity ﬁlter that is appropriately sized to the return air duct opening or external ﬁlter rack.

WARNING:

Never operate the furnace without a ﬁlter in place. Dust and lint can build up on internal components, resulting in loss of efﬁciency, equipment damage, and possible ﬁre.

It is recommended that ﬁlter(s) be 1” or 2” thick and be cleaned or replaced monthly.

Filters designed to remove smaller particles such as pollen, may require additional maintenance. Filters for side return and bottom return applications are available from most local distributors.

Blower Compartment - Dirt and lint can create excessive loads on the motor resulting in higher than normal operating temperatures and shortened service life. It is recommended that the blower compartment be cleaned of dirt or lint that may have accumulated in the compartment or on the blower and motor as part of the annual inspection.

Page 28

Cleaning of Burners - If the burners must be cleaned, follow steps 1-12. See

for component location.

41)

1. Shut off gas supply to the furnace at the meter or at a manual valve in the supply piping.

2. Turn off all power to the furnace and set the thermostat to it’s lowest setting.

3. Remove the burner door from the furnace.

4. Turn the gas control switch to the OFF position.

5. Disconnect the wires from the gas valve, igniter, ﬂame sensor, and ﬂame rollout switch.

Figure 37 (page 41) or Figure 38 (page

CAUTION:

To prevent damage to the unit or internal components, it is recommended that two wrenches be used when loosening or tightening nuts. Do not over tighten!

6. Using two wrenches, separate the ground-joint union in the gas supply piping at the furnace.

7. Remove the piping between the Gas Valve and the groundjoint union. (If applicable).

8. Remove all screws securing the Manifold Assembly to the Burner Box.

9. Carefully remove the burner assembly from the furnace.

DO NOT DAMAGE THE IGNITER WHILE REMOVING THE BURNER ASSEMBLY.

10. Inspect the burners for accumulated dust or debris. If

necessary carefully clean them with a soft wire brush and a vacuum cleaner. DO NOT DAMAGE THE IGNITER

WHILE CLEANING THE BURNER.

11. Replace all the parts in reverse order from which they

were removed.

12. Follow the lighting instructions found on the furnace door to return the furnace to operation. Verify proper operation after servicing.

Vent System - Check the inlet pipe (if applicable) and outlet pipe to ensure they are not blocked by debris. Any damaged section of vent pipe must be replaced, and any obstruction or blockage must be removed prior to operating the furnace.

Heat Exchanger & Burner Maintenance - The furnace should operate for many years without soot buildup in the ﬂue passageways, however, the ﬂue, vent system, and burners should be inspected and cleaned (if required) by a qualiﬁed service technician annually to ensure continued safe operation. Pay attention to any deterioration from corrosion or other sources.

WARNING:

Holes in the vent pipe or heat exchanger can cause combustion products to enter the home. Replace the vent pipe or heat exchanger if leaks are found. Failure to prevent the circulation of combustion products into the living space can create potentially hazardous conditions including carbon monoxide poisoning that could result in personal injury or death.

Lubrication - The bearings in the blower motor and inducer

blower used in these furnaces are pre-lubricated and sealed by the manufacturer. No further oiling of the bearings is required for the life of the motor.

Page 29

LEFT SIDE

RIGHT SIDE

TOP VIEW

BOTTOM VIEW

FRONT VIEW

J951X*U UPFLOW /

1 1/4

BOTTOM VIEW

TOP VIEW

LEFT SIDE

RIGHT SIDE

FRONT VIEW

HORIZONTAL FURNACES

MODEL #’S DIM. -A- DIM -B- DIM -C-

J951X038BU J951X054BU J951X072CU J951X090CU J951X108DU J951X120DU

17 1/2 15 7/8 16 1/8

21 19 3/8 19 5/8

24 1/2 22 7/8 23 1/8

FIGURES & TABLES

FLANGES

23 1/2

Front Brace

Bottom

Panel

NOTE: Dimensions shown in inches.

2 3/4

22 1/2

25 3/8

22 1/2

Vent pipe

(Ø 3”)

34 1/2

17 1/4

Figure 29. J951X*U Cabinet Dimensions

J951X*D DOWNFLOW FURNACES

MODEL #’S DIM. -A- DIM. -B- DIM. -C-

J951X054BD 17 1/2 15 7/8 16 1/8

J951X072CD

J951X090CD

NOTE: Dimensions shown in inches.

21 19 3/8 19 5/8

22 1/2

22 1/4

25 1/2

T-stat

(Ø 7/8)

Electric

(Ø 7/8)

Gas

(Ø 1 5/8)

17 7/8

Condensate

(Ø 1 1/16)

2 3/4

Electric (Ø 7/8)

Gas (Ø 1 5/8)

3 1/4

Flue

Combustion Air

FLANGES

T-stat

(Ø 7/8)

Vent pipe

(Ø 3”)

Combustion

Air

7 1/2

Electric (Ø 7/8)

Gas

(Ø 1 5/8)

24 7/8

T-stat

(Ø 7/8)

Electric (Ø 7/8)

22 1/2

Gas (Ø 1 5/8)

4 Knockouts (both sides)

Cond. (Ø 1 1/16)

Front

Brace

18 1/2

22 1/4

Vent pipe

(Ø 3”)

34 1/2

Cond. (Ø 1 1/16)

22 1/2

Vent pipe

(Ø 3”)

17 1/4

10 1/4

Figure 30. J951X*D Cabinet Dimensions

22 1/2

17 1/4

22 1/2

25 3/8

Cond. (Ø 1 1/16)

29 1/2

17 7/16

Page 30

Electrical Information

IGNITOR

INDUCER

FLAME SENSOR

DOOR

SWITCH

GAS

VALV E

FLAME

ROLLOUT

SUPPLY

AIR LIMIT

PRESSURE

SWITCH

24 V

120 V

WHITE

BLACK

WHITE W/ BLK STRIPE

BLK W/ WHITE STRIPE

1234

123456789

VENT

LIMIT

BLOWER

LIMIT

BLOWER

DECK

LIMIT

BLOWER

LIMIT

MOTOR

12345NLCG

NOTE: FOR

BLOWER

WIRING SEE

BLOWER TABLE

LITERAT URE

123

456

123

456

789

RCYGW

LOW

HIGH

EAC

XFMR

HUM

COM

GREEN

YELLOW

RED

3 AMP FUSE

24V

COM

L1A

NEUTRALS

1234

24V

MOTOR

CHOKE

BLACK

FIELD WIRING

LEGEND:

LOW VOLTAGE

HIGH VOLTAGE

WIRING DIAGRAM

For Single Stage Furnaces

Refer to the Installation Instructions

provided with the furnace for the

proper heating and cooling speeds

for your application.

If any of the original wire as supplied with

the furnace must be replaced, it must be

replaced with wiring material having a

temperature of at least 105 C.

Use copper conductors only.

Diagnostic Description

Green LEDRed LED

Control Fault (No Power) OffOff

L1 / Neutral Polarity Fault FlashFlash

1 Hour Lockout

nOnOnoitarepO lamroN

Pressure Switch Closed Fault On Flash

Pressure Switch Open FaultFlash On

Open Limit Switch Fault FlashOff

Diagnostic Description

Low Flame Sensor Signal

Flame Present

FAULT CONDITIONS

Yellow LED

Continuous Flash

Alternating Flash

10284900

(Replaces 1027315A)

08/19

BLACK

WHITE

BLACK

YELLOW

GREEN

BLUE

GREEN

BLUE

GRAY

BLACK

WHITE

BLACK

BLUE

ORANGE

RED

WHITE

BLACK

WHITE BLACK

BLUE

ORANGE

RED

BLACK

BLUE

ORANGE

RED

GRAY

GREEN

BK/WH STRIPE

(ON SELECT

MODELS)

(ON SELECT

MODELS)

PRESSURE

SWITCH

(ON SELECT

MODELS)

WHITE (NEUTRAL)

BLACK 120 VAC

GROUND

(ON

SELECT

MODELS)

MOTOR

CHOKE

BLACK

BLACK BLACK

(ON SELECT

MODELS)

Figure 31. Wiring Diagram

Page 31

LADDER DIAGRAM

Single Stage Furnaces

DOOR

SWITCH

BLOWER

MOTOR

HUMIDIFIER

INDUCER

TRANSFORMER

XFORMER

CHOKE

(SOME MODELS)

P1-7

EAC

P2-3

HUM

P2-1

120 VAC

FLAME SENSOR

ELECTRONIC

AIR CLEANER

HOT SURFACE IGNITOR

L1 GND N

GND

NEUTRAL

P2-6

NEUTRAL

P2-4

NEUTRAL

See Note

3A FUSE

P1-9

24V

GND

LEGEND:

FIELD WIRING LOW VOLTAGE

HIGH VOLTAGE

MICRO

24V

K5 HI

24 VAC

TO MOTOR

RELAYS

P1-8

P1-3

P1-6

P1-5

P1-4

P1-2

COM

MED-HI

MED-LO

SUPPLY AIR

LIMIT

PRESSURE

SWITCH

GAS

VLV

BLOWER

MOTOR

ROLL-OUT

LIMIT

BLOWER

LIMIT

SWITCH

VENT LIMIT

BLOWER

DECK LIMIT

SWITCH

See Note

Quantity and types of limits and switches may vary with models.

(10299670)

1029967A

02/2020

Figure 32. Ladder Diagram

Page 32

Gas Information

Cubic Feet Per Hour Required =

Input To Furnace (Btu/hr)

Heating Value of Gas (Btu/Cu. Ft.)

(CUBIC FEET PER HOUR)

TIME FOR

ONE REVOLUTION

(SECONDS)

10 360 1,800 3,600

12 300 1,500 3,000

14 257 1,286 2,571

16 225 1,125 2,250

18 200 1,000 2,000

20 180 900 1,800

22 164 818 1,636

24 150 750 1,500

26 138 692 1,385

28 129 643 1,286

30 120 600 1,200

32 113 563 1,125

34 106 529 1,059

36 100 500 1,000

38 95 474 947

40 90 450 900

42 86 429 857

44 82 409 818

46 78 391 783

48 75 375 750

50 72 360 720

52 69 346 692

54 67 333 667

56 64 321 643

58 62 310 621

60 60 300 600

62 58 290 581

64 56 281 563

GAS FLOW RATES

CUBIC FEET PER

REVOLUTION OF GAS METER

1 5 10

GAS FLOW RATES

(CUBIC FEET PER HOUR)

TIME FOR

ONE REVOLUTION

(SECONDS)

66 55 273 545

68 53 265 529

70 51 257 514

72 50 250 500

74 49 243 486

76 47 237 474

78 46 231 462

80 45 225 450

82 44 220 439

84 43 214 429

86 42 209 419

88 41 205 409

90 40 200 400

92 39 196 391

94 38 191 383

96 38 188 375

98 37 184 367

100 36 180 360

102 35 176 353

104 35 173 346

106 34 170 340

108 33 167 333

110 33 164 327

112 32 161 321

114 32 158 316

116 31 155 310

118 31 153 305

120 30 150 300

CUBIC FEET PER

REVOLUTION OF GAS METER

1 5 10

NOMINAL PIPE

DIAMETER (IN.)

1/2 130 90 75 65 55 50 45 40

3/4 280 190 150 130 115 105 95 90

1 520 350 285 245 215 195 180 170

1 1/4 1,050 730 590 500 440 400 370 350

1 1/2 1,600 1,100 890 760 670 610

The cubic feet per hour listed in the table above must be greater than the cubic feet per hour of gas ﬂow required by the furnace. To determine the cubic feet per hour of gas ﬂow required by the furnace, divide the input rate of the furnace by the heating value (from gas supplier) of the gas.

Table 6. Gas Flow Rates

CAPACITY OF BLACK IRON GAS PIPE (CU. FT. PER HOUR)

FOR NATURAL GAS W/ SPECIFIC GRAVITY = 0.60

LENGTH OF PIPE RUN (FEET)

10 20 30 40 50 60 70 80

NOTE:

Table 7. Gas Pipe Capacities

Page 33

HIGH ALTITUDE DERATION – PROPANE GAS

ALTITUDE ABOVE

SEA LEVEL

0 to 1,999 FT

2,000 to 2,999 FT

3,000 to 4,999 FT

5,000 to 5,999 FT

6,000 to 7,999 FT

8,000 to 10,000 FT

INPUT (BTU)

38,000

(SC MODELS)

38,000

(SD MODELS)

54,000 72,000 90,000 108,000 118,000 120,000

56 60 56 56 56 56 55 55 ORIFICE SIZE

10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 MANIFOLD PRESSURE

56 60 56 56 56 56 55 55 ORIFICE SIZE

9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 MANIFOLD PRESSURE

56 60 56 56 56 56 55 55 ORIFICE SIZE

8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 MANIFOLD PRESSURE

57 61 57 57 57 57 56 56 ORIFICE SIZE

10.0 8.5 10.0 10.0 10.0 10.0 10.0 10.0 MANIFOLD PRESSURE

57 61 57 57 57 57 56 56 ORIFICE SIZE

9.0 8.0 9.0 9.0 9.0 9.0 9.0 9.0 MANIFOLD PRESSURE

57 61 57 57 57 57 56 56 ORIFICE SIZE

8.5 7.5 8.5 8.5 8.5 8.5 8.5 8.5 MANIFOLD PRESSURE

Table 8. High Altitude Deration – Propane Gas

LOCAL HEATING VALUES FOR NATURAL GAS

ALTITUDE ABOVE

SEA LEVEL

650 700 750 800 850 900 950 1,000 1,050

BTU PER CUBIC FOOT

2,000 FT LOW LOW LOW LOW LOW LOW

3,000 FT LOW LOW LOW LOW LOW LOW

4,000 FT LOW LOW LOW LOW LOW

5,000 FT LOW LOW LOW LOW LOW

6,000 FT LOW LOW LOW LOW

7,000 FT LOW LOW LOW LOW

8,000 FT LOW LOW LOW

9,000 FT LOW LOW LOW

10,000 FT LOW LOW

HIGH HIGH HIGH HIGH HIGH HIGH HIGH

HIGH HIGH HIGH HIGH HIGH HIGH

HIGH HIGH HIGH HIGH HIGH

Table 9. Natural Gas Heating Values

HIGH HIGH HIGH

HIGH HIGH HIGH HIGH

Page 34

HIGH ALTITUDE DERATION – NATURAL GAS WITH HIGH HEATING VALUE

ALTITUDE ABOVE

SEA LEVEL

0 to 1,999 FT

2,000 to 2,999 FT

3,000 to 3,999 FT

4,000 to 4,999 FT

5,000 to 5,999 FT

6,000 to 6,999 FT

7,000 to 7,999 FT

8,000 to 8,999 FT

9,000 to 9,999 FT

INPUT (BTU)

38,000

(SC MODELS)

38,000

(SD MODELS)

54,000 72,000 90,000 108,000 118,000 120,000

45 51 47 47 47 47 46 45 ORIFICE SIZE

3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45 ORIFICE SIZE

3.0 3.2 3.2 3.2 3.2 3.2 3.2 3.3 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45 ORIFICE SIZE

2.8 3.0 3.0 3.0 3.0 3.0 3.2 3.1 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45 ORIFICE SIZE

2.7 2.8 2.8 2.8 2.8 2.8 2.8 2.9 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45 ORIFICE SIZE

2.5 2.5 2.7 2.7 2.7 2.7 2.7 2.8 MANIFOLD PRESSURE

49 53 49 49 49 49 48 48 ORIFICE SIZE

3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 MANIFOLD PRESSURE

49 53 49 49 49 49 48 48 ORIFICE SIZE

3.4 3.2 3.3 3.3 3.3 3.3 3.3 3.3 MANIFOLD PRESSURE

49 53 49 49 49 49 48 48 ORIFICE SIZE

3.2 3.0 3.0 3.0 3.0 3.0 3.0 3.0 MANIFOLD PRESSURE

49 53 49 49 49 49 48 48 ORIFICE SIZE

3.0 2.8 2.8 2.8 2.8 2.8 2.8 2.8 MANIFOLD PRESSURE

Table 10. High Altitude Deration – Natural Gas with HIGH Heating Value

HIGH ALTITUDE DERATION – NATURAL GAS WITH LOW HEATING VALUE)

ALTITUDE ABOVE

SEA LEVEL

0 to 1,999 FT

2,000 to 2,999 FT

3,000 to 3,999 FT

4,000 to 4,999 FT

5,000 to 5,999 FT

6,000 to 6,999 FT

7,000 to 7,999 FT

8,000 to 8,999 FT

9,000 to 9,999 FT

INPUT (BTU)

38,000

(SC MODELS)

38,000

(SD MODELS)

54,000 72,000 90,000 108,000 118,000 120,000

45 51 47 47 47 47 46 45 ORIFICE SIZE

3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45 ORIFICE SIZE

3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45 ORIFICE SIZE

3.1 3.4 3.3 3.3 3.3 3.3 3.3 3.4 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45 ORIFICE SIZE

2.9 3.2 3.1 3.1 3.1 3.1 3.1 3.2 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45 ORIFICE SIZE

2.8 3.1 2.9 2.9 2.9 2.9 2.9 3.1 MANIFOLD PRESSURE

45 51 47 47 47 47 46 45

2.6 2.9 2.8 2.8 2.8 2.8 2.8 2.9

ORIFICE SIZE

MANIFOLD PRESSURE

48 53 49 49 49 49 48 48 ORIFICE SIZE

3.3 3.5 3.4 3.4 3.4 3.4 3.4 3.5 MANIFOLD PRESSURE

48 53 49 49 49 49 48 48 ORIFICE SIZE

3.0 3.3 3.2 3.2 3.2 3.2 3.2 3.3 MANIFOLD PRESSURE

48 53 49 49 49 49 48 48 ORIFICE SIZE

2.8 3.1 2.9 2.9 2.9 2.9 2.9 3.1 MANIFOLD PRESSURE

Table 11. High Altitude Deration – Natural Gas with LOW Heating Value

Page 35

Venting Information

T PERMITTED

VENT TERMINAL

CLEARANCE LOCATION

Clearance above grade, veranda, porch, deck,

A =

balcony, or maximum expected snow level.

Clearance to window or door

B =

that may be opened.

C = Clearance to permanently closed window * * *

Vertical clearance to ventilated sofﬁt located above the terminal within a horizontal distance

D =

of 2 feet (61cm) from the center line of the terminal.

E = Clearance to unventilated sofﬁt. * * *

F = Clearance to outside corner. * * *

G = Clearance to inside corner. * * *

Clearance to each side of center line extended

H =

above meter/regulator assembly.

I = Clearance to service regulator vent outlet. 3 feet (1.83m) * *

Clearance to non-mechanical air supply inlet to

J =

building or the combustion air inlet to any other appliance.

K = Clearance to mechanical air supply inlet. 6 feet (1.83m)

Clearance above paved sidewalk or driveway

L =

located on public property.

Clearance under veranda, porch, deck, or

M =

balcony.

AIR SUPPLY INLET

CANADIAN INSTALLATIONS

DIRECT VENT (2-PIPE) &

CONVENTIONAL VENT (1-PIPE)

appliances < 10,000 Btuh (3kW)

12 inches (30cm) for appliances

10,000 Btuh - 100,000 Btuh (30kW)

appliances > 100,000 Btuh (30Kw)

3 feet (91cm) within a height 15 feet above the meter/regulator assembly

appliances < 10,000 Btuh (3kW)

12 inches (30cm) for appliances

10,000 Btuh - 100,000 Btuh (30kW)

appliances > 100,000 Btuh (30Kw)

FURNACES

12 inches (30cm) 12 inches (30cm) 12 inches (30cm)

6 inches (15cm) for

36 inches (91cm) for

* * *

6 inches (15cm) for

36 inches (91cm) for

7 feet (2.13m)

12 inches (30cm)

AREA WHERE TERMINAL IS NO

DIRECT VENT

(2-PIPE) FURNACES

6 inches (15cm) for

appliances < 10,000 Btuh (3kW)

9 inches (23cm) for appliances

10,000 Btuh - 50,000 Btuh (30kW)

12 inches (30cm) for

appliances > 50,000 Btuh (30Kw)

6 inches (15cm) for

appliances < 10,000 Btuh (3kW)

9 inches (23cm) for appliances

10,000 Btuh - 50,000 Btuh (30kW)

12 inches (30cm) for

appliances > 50,000 Btuh (30Kw)

3 feet (91cm) above if within

10 feet (3m) horizontally

US INSTALLATIONS

4 ft. (1.2m) below or to side

* *

4 ft. (1.2m) below or to side

3 ft. (91cm) above if within

* 7 ft. (2.13m)

* *

CONVENTIONAL VENT

(1-PIPE) FURNACES

of opening; 1 ft. (300mm)

above opening

of opening; 1 ft. (300mm)

above opening

10 feet (3m) horizontally

a: In accordance with the current CSA B149.1 Natural Gas and Propane Installation Guide Code b: In accordance with the current ANSI Z223.1 / NFPA 54 Natural Fuel Gas Code c: A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings. d: Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the ﬂoor. * For clearances not speciﬁed in ANSI Z223.1 / NFPA 54 or CSA B149.1, the following statement shall be included: “Clearance in accordance with local installation codes, and the requirements of the gas supplier and the manufacturers installation instructions”

Table 12. Vent Termination Clearances

Page 36

J951X*U & J951X*D Series

HORIZONTAL VENTING w/ 2-Pipes

(Upflo

VER

(Upflo

w Furnace Shown)

90°

Elbow

See Table 2 for 2” PVC pipe

lengths (ﬁeld supplied)

Clamps (Optional)

Coupling with 2 Hose

COMBUSTION AIR

90° Elbow

Straps or Other Suitable

Supports at minimum of 5 ft. Intervals

Upward Pitch - 1/4” per foot

(Flue Pipe)

First support placed as close

to furnace connection as possible

FLUE PIPE

PVC Tee

PVC Trap

Wall

Seal/Caulk

Around Pipes

at Building

90°

Elbow

7”

Normal

Snow Level

12” Min.

TICAL VENTING w/ 2-Pipes

w Furnace Shown)

Support System on

Vertical Rise

See Table 2 for 2” PVC pipe

lengths (ﬁeld supplied)

Couplings with 2

COMBUSTION AIR

Hose Clamps (Optional)

FLUE PIPE

PVC Tee

PVC Trap

First Support as Close to Furnace as Possible

90° Elbow

(both ends)

Support System on

Vertical Rise

COMBUSTION AIR

See Table 2 for 2” PVC pipe

lengths (ﬁeld supplied)

FLUE PIPE

PVC Tee

PVC Tr

Figure 33. Horizontal & Vertical Venting

Page 37

J951X*U SERIES UPFLOW - 1 PIPE OPTIONS

Plug

See VIEW A for drain line positions

See VIEW B for drain line positions

COMBUSTION

AIR

NOTE 5

Grommet

OPTION 1

See VIEW A for drain line positions

See

Rubber

FLUE PIPE

PVC Tee

PVC Trap

PVC Tee

PVC Trap

COMBUSTION

AIR

See

FLUE PIPE

NOTE 5

OPTION 2

Rubber

Grommet

See VIEW P for drain line positions

Plug

VIEW -A-

Field Supplied

Drain Line Attached

to PVC Trap

Inline Drain Tube

(Factory Supplied)

See NOTE 4

NOTES:

1. See Accessories section (page 17) for optional PVC Tee conﬁgurations and drainage options.

2. Drain lines must be trapped with a J-Trap or ﬁeld supplied loop. Traps may be positioned inside or outside the cabinet. All drain lines must be routed externally from the cabinet.

3. Inline drain is required only if “X” is greater than 6 feet.

4. Tubing needs to be cut to length and attached during unit installation.

5. Horizontal piping from inducer to ﬂue pipe must be sloped 1/4” per foot to ensure drainage to PVC trapt.

Collector Box Drain

(Factory Equipped)

See NOTES 2 & 3

(Do Not Trap)

Inline Drain Tube

(Field Supplied)

See NOTE 3

VIEW -B-

J951X*U SERIES UPFLOW - 2 PIPE OPTIONS

COMBUSTION AIR

Collector Box Drain (Factory Equipped)

See NOTES 2 & 3

COMBUSTION AIR

OPTION 3

See

Rubber

Grommet

FLUE PIPE

PVC Tee

PVC Trap

See

FLUE PIPE

NOTE 5

PVC Tee

PVC Trap

Rubber

Grommet

NOTE 5

Figure 34. Venting Options for Upﬂow Installations (J951X*U Series)

Plug

OPTION 4

Page 38

J951X*U SERIES HORIZONTAL RIGHT - 1 PIPE OPTION

Option

J951X*U SERIES HORIZONTAL LEFT - 1 PIPE OPTION

Rubber

Grommet

FLUE PIPE

COMBUSTION

AIR

COMBUSTION

AIR

Option

Rubber

Grommet

FLUE PIPE

See VIEW C for

drain line positions

Plug

(Factory Supplied)

Inline Drain

See NOTE 3

VIEW -C-

Inline Drain

(Factory Supplied)

See NOTE 2

Collector Box Drain (Factory Equipped)

See NOTE 2

NOTES:

1. See Accessories section (page 17) for optional PVC Tee conﬁgurations and drainage options.

2. Drain lines must be trapped with a J-Trap or ﬁeld supplied loop. Traps may be positioned inside or outside the cabinet. All drain lines must be routed externally from the cabinet.

3. Tubing needs to be cut to length and attached during unit installation.

J951X*U SERIES HORIZONTAL RIGHT - 2 PIPE OPTION

Option

Rubber

Grommet

FLUE PIPE

J951X*U SERIES HORIZONTAL LEFT - 2 PIPE OPTION

See VIEW D for

drain line positions

FLUE PIPE

Plug

Rubber

Grommet

VIEW -D-

Collector Box Drain (Factory Equipped)

See NOTE 2

Option

See VIEW C for

drain line positions

COMBUSTION AIR

Flange

COMBUSTION AIR

See VIEW D for

Plug

drain line positions

Plug

Figure 35. Venting Options for Horizontal Installations (J951X*U Series)

Page 39

Plug

J951X*D SERIES DO

WNFLOW - 1 PIPE OPTIONS

See

or drain line positions

See VIEW G for drain line positions

See VIEW F for drain line positions

See VIEW E for drain line positions

J951X*D SERIES DO

Plug

Option

Plug

VIEW E for drain line positions See VIEW F for drain line positions

Inline Drain

(Factory Supplied)

See NOTE 4

NOTES

1. See Accessories section (page 17) for optional PVC Tee conﬁgurations and drainage options.

2. Drain lines must be trapped with a J-Trap or ﬁeld supplied loop. Traps may be positioned inside or outside the cabinet. All drain lines must be routed externally from the cabinet.

3. Inline drain is required only if “X” is greater than 6 feet.

4. Tubing needs to be cut to length and attached during unit installation.

5. Horizontal piping from inducer to ﬂue pipe must be sloped 1/4” per foot to ensure drainage to PVC trap.

COMBUSTION

AIR

VIEW -E-

See

NOTE 5

Grommet

FLUE PIPE

Rubber

(Factory Supplied)

Collector Box Drain (Factory Equipped)

See NOTE 2

PVC Tee

PVC Trap

Inline Drain

See NOTE 4

Field Supplied

Drain Line Attached

to PVC Trap

(Do Not Trap)

Rubber

Grommet

Option

Plug

Collector Box Drain

(Factory Equipped)

See NOTE 2

COMBUSTION

FLUE PIPE

VIEW -F-

AIR

Plug

Field Supplied

Drain Line Attached

to PVC Trap

(Do Not Trap)

PVC Tee

PVC Trap

See

FLUE PIPE

NOTE 5

Rubber

Grommet

See VIEW G f

Inline Drain

(Field Supplied)

See NOTES 2 & 3

COMBUSTION

AIR

Option

VIEW -G-

Collector Box Drain

(Factory Equipped)

See NOTE 2

Plug

Option

WNFLOW - 2 PIPE OPTIONS

Rubber

Grommet

Flange

COMBUSTION AIR

Flange

COMBUSTION AIR

FLUE PIPE

Option

Plug

PVC Tee

PVC Trap

See

FLUE PIPE

NOTE 5

Rubber

Grommet

See

NOTE 5

Rubber

Grommet

FLUE PIPE

PVC Tee

PVC Trap

Figure 36. Venting Options for Downﬂow Installations (J951X*D Series)

Plug

Option

Flange

COMBUSTION AIR

Page 40

TROUBLESHOOTING

If the furnace fails to operate check the following:

• Is the thermostat operating properly?

• Are the blower compartment door(s) in place?

• Is the furnace disconnect closed?

• Has the circuit breaker tripped or the control board fuse

burned open?

• Is the gas turned on?

• Are any manual reset switches open?

• Is the ﬁlter dirty or plugged?

• Is the ﬂame sensor coated? (Remove and clean with

steel wool. (Do not use emery cloth or sandpaper!)

• Is there blockage in the condensate drain switch? Also

verify that there is no double trapping of condensate.

• Is the secondary heat exchanger free of debris and

clogs?

• Is evaporator coil clean and free of debris (If applicable).

• Are all the LED’s on the furnace control board constantly

ON? If not, refer to

31 (page 30)

condition.

• Are all the LED’s on the motor control board constantly

ON? If not, refer to

The furnace will lock out after 5 failed attempts for ignition and will try again every hour if the call for heat remains.

• If the Inducer Blower is operating, and items above have

been veriﬁed, check the Blower Limit Switch and reset if necessary. See

for component location.

41)

• If the furnace operates when the Blower Limit Switch is

reset, contact a qualiﬁed service technician to identify and repair the problem.

• If the furnace still doesn’t operate, check the Flame Roll-

out Switches and reset if necessary.

• If the furnace operates when the Flame Rollout Switch

is reset, contact a qualiﬁed service technician to identify and repair the problem.

DIAGNOSTIC DESCRIPTION GREEN LED RED LED

Control Fault (No Power) Off Off

L1/Neutral Polarity Fault Flash Flash

1 Hour Lockout Alternating Flash

Normal Operation On On

Pressure Switch Closed Fault On Flash

Pressure Switch Open Fault Flash On

Open Limit Switch Fault Flash Off

Table 13 or the wiring diagram, Figure

or Figure 32 (page 31) to determine fault

Table 14 to determine fault condition.

IMPORTANT NOTE:

Figure 37 (page 41) or Figure 38 (page

DIAGNOSTIC DESCRIPTION RED LED GREEN LED

Control Fault (No Power) Off Off

Normal Operation On On

Motor Fault On Flash

Twin Fault (No Motor Fault) Flash On

Communications Fault Flash Flash

Table 14. Motor Control Board Fault Conditions

FURNACE COMPONENTS

The descriptions below are various functional components that affect the operation and shutting down of this furnace. Some of these components and their locations are shown in

Figure 37 (page 41) or Figure 38 (page 41). If any

component of the furnace must be replaced, use only factory authorized replacement parts speciﬁed in the Replacement Parts List provided online.

Condensate Drain Switch: The Condensate Drain Switch will shut down the furnace if the condensate drain from the Collector Pan becomes clogged.

Blower Limit Switch: Prevents operation when blower is not operational.

Flame Sensor: Veriﬁes when a ﬂame has carried over from the igniter to the opposite end burner. If no ﬂame is detected, the furnace will shut down within 4 seconds.

Flame Roll-Out Switch: Veriﬁes that the burner ﬂames are drawn into the heat exchanger tubes. If the burner ﬂames are not properly drawn into the heat exchanger, the ﬂame roll-out switch will close the gas valve and initiate the shutdown cycle.

Gas Valve: Controls the ﬂow of gas to the burners. When the gas valve is energized it automatically opens and regulates the gas pressure in the manifold.

Inducer Assembly: Vents products of combustion to the outside.

Pressure Switches: Veriﬁes that the inducer is drawing the combustion gases through the heat exchanger. The pressure switch prevents furnace operation with excessive ﬂue/condensate blockage or improper inducer operation.

Supply Air Limit Switch: Prevents the air temperature leaving the furnace from exceeding the maximum allowable outlet air temperature.

DIAGNOSTIC DESCRIPTION YELLOW LED

Low Flame Sensor Signal Continuous Flash

Flame Present On

Table 13. Control Board Fault Conditions

Page 41

Assembly

Switch

(behind

Manifold

nace Control Board

DOWNFLOW FURNACE (J951X*D SERIES)

Flame

Furnace Control Board

Blower Assembly

Main Air Limit Switch

UPFLOW / HORIZONTAL FURNACE (J951X*U SERIES)

Sensor

Inducer Limit Switch

Pressure Switch

(Inducer)

Inducer Assembly

Blower Door Switch

Motor Choke

Finish

Flange

Roll-Out

Switch

Assembly

Igniter

Gas Valve

Pressure Switch

(Condensate)

Transformer

1234567

Motor Control Board

Figure 37. J951X*U Component Locations

Blower Assembly

blower panel)

Blower Door Switch

(behind blower panel)

Inducer Limit Switch

Gas Valve

Igniter

Finish Flange

Fur

Transformer

Inducer Assembly

Pressure Switch

Flame Sensor

Figure 38. J951X*D Component Locations

Burner

Roll-Out

Gas

Page 42

Page 43

Page 44

INSTALLATION CHECKLIST

INSTALLER NAME:

CITY: STATE:

INSTALLATION ADDRESS:

CITY: STATE:

UNIT MODEL #

UNIT SERIAL #

Minimum clearances per Figure 1

(page 5)?

Has the owner’s information been reviewed with the home-owner?

Has the literature package been left near the furnace?

YES NO

ATTENTION INSTALLERS:

It is your responsibility to know this product better than your customer. This includes being able to install the product according to strict safety guidelines and instructing the customer on how to operate and maintain the equipment for the life of the product. Safety should always be the deciding factor when installing this product and using common sense plays an important role as well. Pay attention to all safety warnings and any other special notes highlighted in the manual. Improper installation of the furnace or failure to follow safety warnings could result in serious injury, death, or property damage.

These instructions are primarily intended to assist qualiﬁed individuals experienced in the proper installation of this appliance. Some local codes require licensed installation/service personnel for this type of equipment. Please read all instructions carefully before starting the installation. Return these instructions to the customer’s package for future reference.

ELECTRICAL SYSTEM

Electrical connections tight? YES NO

Line voltage polarity correct? YES NO

Supply Voltage: ............................................................... VOLTS

Has the thermostat been calibrated? YES NO

Is the thermostat level? YES NO

Is the heat anticipator setting correct? YES NO

GAS SYSTEM

Gas Type: (circle one)

Gas pipe connections leak tested? YES NO

Gas Line Pressure: .......................................................... (in - W.C.)

Installation Altitude:............................................................(FT.)

Deration Percentage: .........................................................(%)

Furnace Input:....................................................................(Btuh)

Supply Air Temperature: ...................................................(° F)

Return Air Temperature: ...................................................(° F)

Temperature Rise: ............................................................(° F)

COMBUSTION AIR & VENTING SYSTEM

Natural

Gas

Propane

MH63349

(03/20)

G7SC MGC2S G7SD G7SL

Is there adequate fresh air supply for combustion and ventilation?

Vent free from restrictions? YES NO

Filter(s) secured in place? YES NO

Filter(s) clean? YES NO

Flue connections tight? YES NO

Is there proper draft? YES NO

YES NO

1027035A

(Replaces 10270350)