HP 422690 I User Manual

HIGH-EFFICIENCY UPFLOW FURNACE

INSTALLER'S INFORMATION MANUAL

ATTENTION, INSTALLER! After installing the

furnace, show the user how to turn off gas and electricity to the furnace. Point out control and switch locations for turning off gas and electricity. Go over the User’s Information Manual and Section 23, “Maintaining Fu rnace In Good Working Order" in this manual with the user. Make sure the user understands the importance of following all safety precautions , including what could happen if they do not.

Attach the following documents to or adjacent to the furnace. Tell the user where these documents are located.

• User's Information Manual

• Installer's Information Manual

• Parts List

• Warranty Informat ion While these instructions have been written as accurately

and thoroughly as possible, they can not cover every system variation or contingency. Questions of interpretation may arise. For more information, solutions to particular problems or clarification, contact your local distributor or the manufacturer.

ATTENTION, USER! Your furnace installer should

give you the documents listed on opposite side. You should immediately read the User’s Information Manual for important safety information to keep you and your family safe. Keep these as long as you keep your furnace. Pass them on to future furnace purchasers or users. If any of the documents are missing or illegible, contact your installer or furnace manufacturer for replacement. Throughout this manual, when we use the word "you" we refer to the qualified service technician who is responsible for application, installation and service of your furnace.

?? 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.

• Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's inst ructions.

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

WARNING: Individuals who install this fu rnace, must have the training and experience necessary to install gas furnaces. They must also have training and experience necessary to install related comfort air conditioning appliances. Improper installation could create a hazard, resulting in the possibility of damage, injury or death.

422690 I

TABLE OF CONTENTS

SECTION 1. IMPORTANT SAFETY RULES ............................................................................................................. 2

SECTION 2. MEETING CODES .............................................................................................................................. 3

SECTION 3. DETERMINING BEST FURNACE LOCATION...................................................................................... 3

SECTION 4. PROVIDING VENTIN G AND COMBUSTION AIR.................................................................................. 5

SECTION 5. CONDENSATE DRAIN.......................................................................................................................14

SECTION 6. INSTALLIN G GAS PIPING ..................................................................................................................14

SECTION 7. INSTALLING ELECTRICAL WIRING...................................................................................................15

SECTION 8. SEQUENCE OF OPERATION ............................................................................................................17

SECTION 9. INSTALLIN G DUCT SYSTEM.............................................................................................................18

SECTION 10. SELECTIN G AND INSTALLING FILTER CABINETS ..........................................................................18

SECTION 11. CHECKS BEFORE STARTING FURNACE ........................................................................................20

SECTION 12. GAS SUPPLY PRESSURE AND PILOT ADJUSTMENT .....................................................................20

SECTION 13. MANIFOLD PRESSURE ADJUSTMENT...........................................................................................21

SECTION 14. CHECKING GAS INPUT RATE .........................................................................................................21

SECTION 15. DERATING FOR HIGH ALTITUDE ....................................................................................................22

SECTION 16. DETERMINING CORRECT ORIFICE SIZE ........................................................................................22

SECTION 17. CHANGING MAIN BURNER ORIFICES ............................................................................................23

SECTION 18. ADJUSTIN G BLOWER SPEED.........................................................................................................24

SECTION 19. MEASURING DUCT SYSTEM STATIC PRESSURE ..........................................................................24

SECTION 20. MEASURING AIR TEMPERATURE RISE ..........................................................................................25

SECTION 21. CHECKING CONTROLS ..................................................................................................................25

SECTION 22. SETTING BLOWER TIMINGS ...........................................................................................................26

SECTION 23. MAINTAINING FURNACE IN GOOD WORKING ORDER...................................................................26

SECTION 24. ACCESSORIES .............................................................................................................................27

SECTION 25. OTHER INFORMATION AND PUBLICATIONS ..................................................................................27

SECTION 1. IMPORTANT SAFETY RULES

To alert you to potential hazards, we use the signal words "WARNING" and "CAUTION" throughout this manual. "WARNING" alerts you to situations that could cause or result in serious injury or death. "CAUTION" alerts you to situations that could cause or result in minor or moderate injury or property damage. For a safe and reliable installation be sure to read and follow all warnings and cautions.

We also use the words "must" and "should" in this manual. "Must" is mandatory. "Should" is advisory.

WARNING: Read and follow the safety rules in this section and throughout this manual. Failure to do so could cause improper furnace operation, resulting in

damage, injury or death.

Rule 1. Use only gas approved for use in this fu rnace, as indicated on fu rnace rating plate. Use only natural gas in furnaces designed for natural gas. Use only propane (LP) gas in furnaces designed for propane (LP) gas. Make sure furnace will operate properly on the gas type available to user. Do not use butane gas in this furnace.

WARNING: Use of a non-approved gas (such as butane) in this furnace could cause sooting or overheating of heat exchanger.

Rule 2. Do not install this fu rnace outdoors or in a mobile home, trailer or recreational vehicle. It is not design certified for these installations. This furnace is suitable for a home built on site or a manufactured home completed at

the final site. Rule 3. Air for combustion must not come from a corrosive

or contaminated atmosphere. Make sure all combustion and ventilation air requirements are adhered to in addition to local codes and ordinances.

Rule 4. This furnace is not to be used for temporary heating of buildings or structures under construction.

Rule 5. Provide adequate combustion and ventilation air to space where furnace is being installed unless combustion air is provided directly through an inlet air pipe. Connect this furnace to an approved vent system--venting combustion products outdoors.

Rule 6. Check for gas leaks anytime work is done on gas supply line, fu rnace gas control, pilot and pilot line or main burner manifold.

Rule 7. Never test for gas leaks with an open flame. Use a commercial soap solution made specifically for leak detection to check all connections.

Page 2 Installer’s Information Manual

Rule 8. Completely seal supply and return air ducts to furnace casing. Duct system must run to an area outside furnace room or closet. Seal duct work wherever it runs through walls, ceilings or floors of furnace room or closet.

SECTION 2. MEETING CODES

This furnace complies with American National Standard and National Standard of Canada for Gas Fired Central Furnaces, ANSI Z21.47 ? CAN/CGA-2.3. It is certified for operation with either natural gas or propane (LP) gas for indoor installation in a building constructed on site. It meets the requirement for a 100% shut -off gas control system.

Provide ample space for servicing and cleaning. Location must allow 30 inches minimum front clearance for service.

WARNING : Some insulating materials are combustible. When a furnace is installed in an attic or other insulated space, keep all insulating materials at least 12 inches away from furnace and combustion air inlet. Failure

to do so could cause a fire.

You may install fu rnace on non-combustible flooring or on wood flooring.

Before installing this furnace, make sure you know all applicable codes. Be sure to consult local authorities having jurisdiction over furnaces for information on electrical wiring, gas piping and venting. The installation of this furnace must conform with local building codes or in the absence of local codes, with ANSI Z223.1, National Fuel Gas Code or CAN/CGA B149, Canadian Installation Codes.

Electrical wiring must conform with local building codes or in the absence of local codes, with the current National Electrical Code, ANSI/NFPA 70 or current Canadian Electrical Code, CSA C22.1.

SECTION 3. DETERMINING BEST FURNACE LOCATION

You may install this upflow furnace in an alcove, attic, basement, closet, garage or utility room. Do not install furnace in an area subject to freezing temperatures.

This furnace operates best when return-air temperature is between 55°F and 80°F. Do not install furnace in a location subject to continuous higher or lower temperatures. Continuous operation outside of this range may shorten furnace life.

WARNING : Do not install furnace in any other position other than upflow. Doing so could cause heat exchanger blockage and damage to heat exchanger.

Select a location that meets all requirements described in this manual for the following:

?? Safety ?? Minimum Clearances ?? Combustion and Ventilation Air ?? Venting ?? Duct System ?? Gas Piping ?? Electrical Wiring

Locate fu rnace as near to the center of the air distribution system as possible.

WARNING : Do not install furnace on carpeting, tile or other combustible material except wood flooring.

Doing so could cause a fire.

Install fu rnace so all electrical components are protected from water.

Level fu rnace from front to back and from left to right within 1/4 inch. Furnace must be installed level for proper condensate drainage. Furnace will not operate if condensate does not drain.

When fu rnace is located within the heated space, exhaust fans can adversely affect its operation. Exhaust fans in kitchen, bathrooms, clothes dryers or anywhere within heated space, increase combustion air requirements of non-direct vented fu rnaces. This is because exhaust fans reduce the amount of combustion air available to the furnace. A fireplace also reduces amount of combustion air.

Sufficient air must be provided to ensure there will not be a negative pressure in fu rnace room or space. In addition, there must be a positive seal between fu rnace and return air duct to avoid pulling air from burner area.

When a cooling unit is installed with this furnace, the furnace must be installed parallel with or on the upstream side of the cooling unit to avoid condensation in fu rnace heat exchanger. With a parallel flow arrangement, the dampers or other means used to control flow of air must be adequate to prevent chilled air from entering the fu rnace and, if manually operated, must be provided with a means to prevent operation of either unit unless damper is in the

full heat or cool position. When furnace is in a residential garage, it must be installed

so that pilot and main burners are located no less than 18 inches above the floor. Also, fu rnace should be protected from physical damage by vehicles.

When fu rnace is in a public garage, airplane hanger, or other building having hazardous atmosphere, install unit in accordance with recommended good practice requirements of the National Fire Protection Association, Inc. Consult

local code authorities for additional location requirement s. See Figure 1 for furnace dimensions and clearances.

Installer’s Information Manual Page 3

GAS

INPUT*

(Btu/hr) (HP) “A” “B” “C” TOP SIDES BACK FRONT VENT (INCHES)

54,000 1/3 17 1/2 15 3/4” 15 15/16” 1 0 0 2 0 2 72,000 1/2 17 1/2 15 3/4” 15 15/16” 1 0 0 2 0 2 OR 3 72,000 3/4 20 1/2 18 3/4” 18 15/16” 1 0 0 2 0 2 OR 3 90,000 1/2 17 1/2 15 3/4” 15 15/16” 1 0 0 2 0 2 OR 3

90,000 3/4 20 1/2 18 3/4” 18 15/16” 1 0 0 2 0 2 OR 3 108,000 3/4 23 1/2 21 3/4” 21 15/16” 1 0 0 2 0 3 126,000 3/4 23 1/2 21 3/4” 21 15/16” 1 0 0 2 0 3

* See Furnace Rating Plate located on blower door. ** These are furnace dimensions. See Sections 9 and 10 for proper ductwork and floor opening dimensions. *** Certified for installation on wood flooring. 30-inch front clearance required for service. 18-inch front clearance required in an alcove.

MOTOR

SIZE*

FURNACE

WIDTH**

RETURN AIR

SIZE**

SUPPLY AIR

SIZE**

CLEARANCE TO COMBUSTIBLES***

(INCHES)

VENT SIZE

Figure 1. Furnace Dimensions and Clearances.

Page 4 Installer’s Information Manual

SECTION 4. PROVIDING VENTING AND COMBUSTION AIR

This furnace must be connected to a plastic venting system adequate to remove flue gases to the outside atmosphere. It must be vented in accordance with these instructions and local building codes.

The fu rnaces covered by this manual are design-certified as Category IV appliances. Category IV appliances operate with a positive vent static pressure and with a flue gas temperature that will produce significant condensate in the vent. The vent system for this furnace must be installed so as to prevent leakage of flue gases into the building. This furnace may be installed using either direct venting or nondirect venting.

WARNING : Do not connect this furnace to a vent system shared by any other appliance. Do not connect it to any other type of vent system other than described by these instructions. Improper venting could allow combustion products to collect in building during use resulting in nausea

or death by asphyxiation.

GENERAL VENTING GUIDELINES

?? Vent system and combustion air supply components

must be constructed of schedule 40 PVC, PVC -DWV, SDR26, SDR 21 or ABS plastic pipe, fittings, sealants, and installation procedures that conform to the following ANSI/ASTM standards:

PVC ASTM D-1785 SDR26, SDR21 ASTM D-2241 PVC-DWV ASTM D-2665 PVC-DWV Cellular Core ASTM F-891 PVC Primer And Solvent Cement ASTM D-2564 ABS Pipe And Fittings ASTM D-2235 Procedure For Cementing Joints ASTM D-2855

?? All condensate formed in the vent must run back

toward fu rnace for proper drainage. Install vent pipe with no less than a 1/4 inch per foot slope from furnace to vent terminal.

?? Install vent pipe without dips or sags that may hold

water. Support horizontal portions of vent pipe every 5 feet (3 feet for SDR-21 or SDR-26 pipe).

?? Some models are shipped with a 3-inch to 2-inch

reducer bushing. When venting with two-inch pipe, install reducer bushing in flue outlet fitting.

Figure 2. Vent Connection to Furnace.

PVC PIPE INSTALLATION INSTRUCTIONS

1. Cut ends of pipe square using a miter box, power saw or PVC tubing cutter. Put a 10 to 15 degree chamfer on end of pipe. Remove any burrs, dirt, grease, and moisture. Check joint for proper fit.

2. Freely coat outside end of pipe and inside of fitting socket with cleaner-primer. The purpose of the primer is to dissolve and penetrate the surface of the pipe.

Several coats may be necessary to do this.

3. While primer is still wet, apply a heavy coat of solvent cement to outside of pipe. Next, using outward strokes to keep excess cement out of socket, apply a generous coat of cement to the inside of socket.

4. While both surfaces are still wet with cement, insert pipe into fitting socket until it bottoms out, using a slight twisting motion (1/4 turn). Hold pipe in socket 30

seconds to allow cement to set.

5. Allow joint to cure before handling.

Caution: Keep solvent cement container sealed when not in use. Do not use solvent cement that has thickened or is gel-like.

WARNING : PVC cements are highly flammable. Do not use near open flames. A fire or explosion could result. Avoid prolonged breathing or contact with skin or

eyes.

?? Protect vent from freezing. Long runs of vent pipe

installed in an unconditioned space may require insulation to prevent freezing of condensate.

?? Furnace can be vented from either left or right side.

See Figure 2. As shipped, furnace is setup for venting through the left side. Right side venting is accomplished by rotating flue outlet fitting and adding a street elbow to the drain fitting. Street elbow and instructions are supplied in the furnace parts package.

Installer’s Information Manual Page 5

TERMINATION LOCATION AND CLEARANCES

Vent pipe and combustion-air-supply pipe (when direct vented) may terminate through a roof or through a sidewall. Roof termination has the advantages of better pipe protection and fewer condensate -damage concerns. Use

the following guidelines when choosing a vent location: ?? Flue gases can be corrosive. When sidewall venting,

protect walls with a corrosion resistant material. Also, terminate away from plants and shrubs.

?? Locate termination consistent with the National Fuel

Gas Code, ANSI Z223.1/NFPA 54 or the CAN/CGA B149 Installation Codes.

?? Locate termination away from other air intake or

exhaust vents such as dryer vents, other gas appli ance vents, or plumbing vents. Allow at least 3 foot to any

other vent.

?? Terminal must not be located above a walkway,

driveway or within 10 feet of an adjacent building.

?? Do not locate termination underneath a veranda,

porch, or deck.

IN THE UNITED STATES:

?? Allow a minimum clearance of 4 feet from electric

meters, gas meters, regulators, and relief equipment.

?? When non-direct venting, terminal must be at least 4

feet below, or 4 feet horizontally from or one foot above any door, window or gravity air inlet into a building. Terminal must also be at least 3 feet above any forcedair inlet located within 10 feet horizontally.

?? When direct venting, vent terminal must be at least one

foot from any opening through which flue gases could enter a building.

IN CANADA:

?? Allow 6 feet clearance to any mechanical air supply or

service regulator vent and 6 feet horizontally to any gas meter, electric meter, or relief device.

?? Do not terminate above a meter/regulator assembly

within 3 feet horizontally of the vertical center line of the regulator

?? Do not terminate within one foot (3 feet for 108,000 and

126,000 Btu models) of a window or door that can be opened, a non-mechanical-air-supply inlet, or the combustion-air inlet of any other appliance

EXISTING VENT CONSIDERATIONS

When a Category I fu rnace is removed or replaced, the old venting system may not be properly sized to vent the remaining appliance(s), for example, a gas water heater. An improperly sized venting system may promote the

formation of condensate, leakage or spillage.

The following steps shall be followed with each appliance connected to the old venting system placed in operation, while any 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 CAN/CGA B149 Installation Codes. Determine that there is no blockage or restriction, leakage, corrosion and other

deficiencies which could cause an unsafe condition;

3. In so far as is practical, close all building doors and windows and all doors between space in which appliance(s) connected to the venting system are located and other spaces of building.

4. Close fireplace damp ers.

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 shall operate at maximum speed. Do not operate a summer exhaust fan.

6. Follow the lighting instructions. Place the appliance being inspected in operation. Adjust thermostat so appliance shall operate continuously;

7. Test for drafthood equipped appliance spillage at the drafthood relief opening after 5 minutes of main burner

operation. Use the flame of a match or candle;

8. 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 burning appliance to their previous conditions of use;

9. If improper venting is observed during any of the above tests, the venting system must be corrected. Follow the National Fuel Gas Code, ANSI Z223.1/NFPA 54 or CAN/CGA B149 Installation Codes to correct improper vent operation. Any "common vent" re-sizing must approach minimum size determined using current venting tables.

DIRECT OR NON-DIRECT VENTING?

This furnace may be installed using either direct venting or non-direct venting.

A direct-vented fu rnace takes all air for combustion directly into the fu rnace through a pipe from outdoors. To direct vent this furnace you must install two pipes to the outdoors. One pipe supplies combustion air that the furnace needs to operate. The other pipe vents flue gases to the outdoors.

Use direct venting when indoor air may be contaminated with chemicals such as chlorine, fluorine, bromine or iodine. When these chemicals are burned with natural gas or propane gas, acids are produced that may decrease heat exchanger life. You should also consider direct venting when furnace is installed in a space with limited combustion and ventilation air. See “CONFINED SPACE

Page 6 Installer’s Information Manual

INSTALLATION” under the “NON-DIRECT VENTING” instructions.

A non-direct vented furnace takes all air for combustion from the room in which fu rnace is installed. Non-direct venting requires only one pipe for venting the flue gases to the outdoors but you must make sure there is enough air for combustion and ventilation.

DIRECT VENTING INSTRUCTIONS (two pipe system)

DETERMINING VENT LENGTH

See Table 1 for maximum vent and combustion-air pipe length. Include any termination elbows when determining maximum allowable vent length. Minimum vent length is five feet with 0 elbows.

Table 1 shows the maximum allowable pipe lengths for direct vent systems depending on:

?? altitude (elevation) of the installation ?? gas input rating of furnace ?? diameter of the air and vent pipes ?? number of elbows

Note that some of the larger furnace models may require a high altitude pressure switch at elevations between 3000 and 6000 feet. For example, the table shows that the 126,000 Btu/hr model may need a high altitude pressure switch when installed at elevations between 3000 and 4000 feet. Above 4000 feet, this model requires a high altitude switch for all installations.

All furnace models require the high altitude pressure switch when installed at elevations above 6000 feet.

The high-altitude pressure switch is supplied with the LP Conversion Kit #4226000 and the Natural Gas Conversion Kit #4225600. These kits also contain the other components required for furnace installation at high elevations.

NOTE: Table 1 assumes Sweep 90? elbows like that in Figure 3a. If using Hard 90? elbows similar to the one in

Figure 3b, decrease the vent length by 3 feet for every elbow used.

(a) (b) Figure 3. (a) Sweep 90? Elbow. (b) Hard 90? Elbow.

When using a concentric vent kit the following exceptions apply:

?? 90,000 BTU input furnaces must be vented with 3-inch

pipe.

?? For 108,000 BTU input furnaces, reduce the maximum

vent length by 5 feet when 2 sweep elbows are used, 10 feet when 3 sweep elbows are used, 15 feet when 4 sweep elbows are used and so on. For hard 90° elbows reduce vent length in 8-foot interv als.

?? 126,000 BTU input furnaces may not be vented using a

concentric vent.

Installer’s Information Manual Page 7

Table 1. Maximum Pipe Length--Direct Vent

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 40 40 37 33 30 27 23 20

72,000

3" 40 40 40 40 40 40 40 40 0'-1000' 90,000

2" 30 26 22 19 15 11 - -

90,000

3" 40 40 40 40 40 40 40 40

108,000

3" 40 40 40 40 40 40 40 40

126,000

3" 40 40 40 40 35 30 25 20

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 40 37 33 29 25 21 19 15

72,000

3" 40 40 40 40 40 40 40 40 1001'-2000' 90,000

2" 25 22 19 16 12 - - -

90,000

3" 40 40 40 40 40 40 40 40

108,000

3" 40 40 40 40 40 40 40 40 126,000

3" 40 38 33 28 22 16 11 -

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 35 33 29 25 21 17 13 -

72,000

3" 40 40 40 40 40 40 40 40 2001'-3000' 90,000

2" 22 19 16 14 - - - -

90,000

3" 40 40 40 40 40 40 40 40 108,000

3" 40 40 40 40 40 40 40 40

126,000

3" 35 30 25 20 15 10 - -

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 30 28 26 24 22 20 18 17

72,000

3" 40 40 40 40 40 40 40 40 3001'-4000' 90,000

2" 15 13 11 - - - - -

90,000

3" 40 40 40 40 40 40 40 40 108,000

3" 40 40 40 40 40 40 40 40

126,000

3" 30 25 20 15 10 - - -

126,000

3" 40 40 40 40 35 30 25 20

See Note 2 below.

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 26 22 17 14 12 - - -

72,000

3" 40 40 40 40 40 40 40 40 4001'-5000' 9

0,000

3" 40 40 40 40 40 40 40 40

108,000

3" 40 40 40 35 30 25 20 15

108,000

3" 40 40 40 40 40 40 40 40

See Note 2 below.

126,000

3" 40 40 40 40 35 30 25 20

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 21 18 14 11 - - - -

72,000

3" 40 40 40 40 40 40 40 40 5001'-6000' 90,000

3" 40 40 40 40 40 40 40 40

108,000

3" 40 35 30 25 20 15 10 -

108,000

3" 40 40 40 40 40 40 40 40

See Note 2 below.

126,000

3" 40 40 40 40 35 30 25 20

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 40 40 40 40 36 32 28 24 72,000

3" 40 40 40 40 40 40 40 40 6001'-7000' 90,000

3" 40 40 40 40 40 40 40 40

See Note 2 below.

108,000

3" 40 40 40 40 40 40 40 40

126,000

3" 40 40 40 40 35 30 25 20

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 40 40 40 37 35 32 28 24

72,000

3" 40 40 40 40 40 40 40 40 7001'-8000' 90,000

3" 40 40 40 40 40 40 40 40

See Note 2 below.

108,000

3" 40 40 40 40 40 40 40 40

126,000

3" 40 40 40 40 35 30 25 20

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 40 40 37 34 31 28 24 21

72,000

3" 40 40 40 40 40 40 40 40 8001'-9000' 90,000

3" 40 40 40 40 40 40 40 40

See Note 2 below.

108,000

3" 40 40 40 40 40 40 40 40

126,000

3" 40 40 40 35 30 25 20 15

54,000

2" 40 40 40 40 40 40 40 40

72,000

2" 40 37 35 31 27 24 21 18

72,000

3" 40 40 40 40 40 40 40 40 9001'-10000'

90,000

3" 40 40 40 40 40 40 40 40

See Note 2 below.

108,000

3" 40 40 40 40 40 40 40 40

126,000

3" 40 35 30 25 20 15 - -

ALLOWABLE PIPE LENGTH (feet of each pipe)

ALTITUDE FURNACE PIPE

NUMBER OF SWEEP ELBOWS (each pipe) (SEE NOTE 1)

INPUT DIA. 1 2 3 4 5 6 7 8

NOTE 1: The table assumes the use of sweep elbows. If using hard 90? elbows , the vent length should be decreased an

NOTE 2: The shaded portions of the table require the high altitude pressure switch in order to operate the furnace at the listed

Page 8 Installer’s Information Manual

additional 3 feet for every elbow used.

vent lengths.

DIRECT-VENT TERM INATION

You may terminate vent and combustion air pipes either vertically (through the roof) or horizontally (through a side wall). Vertical (through the roof) venting is preferred because it offers protection from pipe damage and condensate damage. You may use concentric vent termination except on 126,000 BTU input furnaces. Follow the instructions supplied with the concentric-vent kit.

For vertical direct venting, combustion air inlet pipe must terminate next to vent pipe and 12 inches above roof (18” in Canada) or highest expected snow accumulation. Extend vent pipe at least 6 inches above combustion air inlet. See Figure 4a for vertical direct vent termination.

Attach a combustion air pipe to combustion-air-inlet collar on top of fu rnace. Use rubber coupling and hose clamps supplied with furnace. See Figure 5.

Figure 5. Combustion Air Pipe Connection to Fu rnace for Direct Vent.

NON-DIRECT VENTING INSTRUCTIONS (one pipe system)

Figure 4a. Vertical Termination for Direct Venting. Combus tion-air-inlet termination must always be pointed

downward to keep out rain and snow. Furnace will not operate properly with water in combustion compartment.

Note: When properly installed, vent pipe is designed to drain condensate and will not be affected by rainwater.

For horizontal direct venting, combustion air inlet must terminate next to vent pipe and at least 12 inches above grade or highest expected snow accumulation. Extend vent pipe at least 12 inches above combustion air inlet. See Figure 4b.

Figure 4b. Horizontal Termination for Direct Venting.

DETERMINING VENT LENGTH

See Table 2 for maximum vent pipe length. Include any termination elbows when determining maximum allowable vent length. Minimum pipe length is five feet with 0 elbows.

Table 2 shows the maximum allowable pipe length for nondirect vent systems depending on:

?? altitude (elevation) of the installation ?? gas input rating of furnace ?? diameter of the vent pipe ?? number of elbows

Note that some of the larger furnace models may require a high altitude pressure switch at elevations between 3000 and 6000 feet. For example, the chart shows that the 126,000 Btu/hr model may need a high altitude pressure switch when installed at elevations between 3000 and 4000 feet. Above 4000 feet, this model requires a high altitude switch for all installations.

All furnace models require the high altitude pressure switch when installed at elevations above 6000 feet.

NOTE: Table 2 assumes Sweep 90? elbows like that in Figure 3a. If using Hard 90? elbows similar to the one in Figure 3b, decrease the vent length by 3 feet for every elbow used.

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