Page 1: Table Of Contents
INSTALLATION INSTRUCTIONS 80% Single Stage, ECM Motor Category I, Gas Furnace N8MXL SAFETY CONSIDERATIONS ......Cleaning Heat Exchanger .
Page 2: Safety Considerations
SAFETY CONSIDERATIONS 1. Use only with type of gas approved for this furnace. Refer to the furnace rating plate. WARNING 2. Install this furnace only in a location and position as spe- cified in the “Location” section of these instructions. 3.
Page 3 used with a night setback thermostat. Return−air temperature For accessory installation details, refer to the applicable must not exceed 80_F (27_C) db. Failure to follow these instruction literature. return−air temperature limits may affect reliability of heat NOTE: Remove all shipping brackets and materials before exchangers, motors, and controls.
Page 4 A10269 Fig. 2 − Clearances to Combustibles 441 01 1421 02 Specifications are subject to change without notice.
Page 5: Codes And Standards
Electrical Connections Current edition of National Electrical Code (NEC) NF- PA 70. Venting Current edition of NFGC NFPA 54 / ANSI Z223.1; Chapters 12 and 13. ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS PROCEDURE CAUTION FURNACE RELIABILITY HAZARD Improper installation or service of furnace may cause premature furnace component failure.
Page 6: Location
THE BLOWER IS LOCATED BELOW THE BURNER SECTION, AND CONDITIONED AIR IS DISCHARGED UPWARD. THE BLOWER IS LOCATED TO THE RIGHT OF THE BURNER SECTION, AND AIR CONDITIONED AIR IS DISCHARGED TO THE LEFT. THE BLOWER IS THE BLOWER IS LOCATED TO THE LEFT LOCATED ABOVE THE OF THE BURNER SECTION,...
Page 7 All fuel−burning equipment must be supplied with air for fuel CAUTION combustion. Sufficient air must be provided to avoid negative pressure in the equipment room or space. A positive seal must be made between the furnace cabinet and the return−air duct to PERSONAL INJURY AND/OR PROPERTY prevent pulling air from the burner area and from draft safeguard DAMAGE HAZARD...
Page 8 Table 3 – Minimum Space volumes for 100% combustion, Ventilation, and Dilution from Indoors OTHER THAN FAN-ASSISTED TOTAL FAN-ASSISTED TOTAL (1,000'S BTUH GAS INPUT RATE (1,000'S BTUH GAS INPUT RATE) ACH* Space Volume (ft. 0.60 1,050 1,400 1,750 1,100 1,650 2,200 2,750 3,300...
Page 9 1 SQ IN. CIRCULATING AIR PER 4000 VENT THROUGH ROOF DUCTS DUCTS BTUH* O UTDOORS 12" MAX (305mm) 12 ″ MAX 12 ″ (305mm) (305mm) 1 SQ IN. VENT 1 SQ IN. PER 2000 THR OUGH PER 1000 BTUH* R OOF BTUH* IN DOOR 1 SQ IN .
Page 10: Installation
INSTALLATION Ifan = combined input of all fan−assisted appliances in Btuh/hr ACH = air changes per hour (ACH shall not exceed 0.60.) UPFLOW INSTALLATION The following requirements apply to the Standard Method and to Bottom Return Air Inlet the Known Air Infiltration Rate Method. These furnaces are shipped with bottom closure panel installed in 1.
Page 11: Downflow Installation
5/ 16  (8mm) (8mm) 5/ 16   (44mm) PLENUM OPENING  (44mm) FLOOR (8mm) OPENING  (8mm) 5/ 16  (44mm) 3/ 4  3/ 4  (44mm) A89014 A96283 Fig. 10 − Leveling Legs Fig. 11 − Floor and Plenum Opening Dimensions 4.
Page 12 FURNACE APPROVED COIL ASSEMBLY COIL BOX COMBUSTIBLE FLOORING SHEET METAL PLENUM FLOOR OPENING A08556 Fig. 13 − Furnace, Plenum, and Coil Assembly or Coil Box Installed on a Combustible Floor Table 4 – Opening Dimensions − In. (mm) FURNACE PLENUM OPENING FLOOR OPENING CASING APPLICATION...
Page 13: Horizontal Installation
HORIZONTAL INSTALLATION Not all horizontal furnaces are approved for side return air connections. (See Fig. 21.) WARNING FILTER ARRANGEMENT WARNING FIRE, EXPLOSION, AND CARBON MONOXIDE POISONING HAZARD CARBON MONOXIDE AND POISONING Failure to follow this warning could result in personal HAZARD injury, death, and/or property damage.
Page 14 Upflow and Horizontal Furnaces Downflow Furnaces Connect supply−air duct to flanges on furnace supply−air outlet. Connect supply−air duct to supply−air outlet on furnace. Bend Bend flange upward to 90_ with wide duct pliers. (See Fig. 14.) flange inward past 90_ with wide duct pliers. (See Fig. 14.) The The supply−air duct must be connected to ONLY the furnace supply−air duct must be connected to ONLY the furnace supply supply−outlet−air duct flanges or air conditioning coil casing...
Page 15 METHOD 2 USE (4) #8 x 3/4 (19 mm) SHEET METAL SCREWS FOR EACH STRAP. THE STRAPS SHOULD BE VERTICAL AGAINST THE FURNACE SIDES AND NOT PULL AWAY FROM THE FURNACE SIDES. METHOD 1 FOLD ALL STRAPS UNDER FURNACE AND SECURE WTH (4) #8 x 3/4 (19 mm) SHEET METAL SCREWS (2 SCREWS IN SIDE AND 2 SCREWS IN BOTTOM).
Page 16: Gas Piping
Return Air Connections WARNING WARNING FIRE OR EXPLOSION HAZARD FIRE HAZARD Failure to follow this warning could result in personal injury, death, and/or property damage. Failure to follow this warning could cause personal injury, death and/or property damage. If local codes allow the use of a flexible gas appliance connector, always use a new listed connector.
Page 17 Table 5 – Air Delivery − CFM (With Filter)* WIRE− Test Airflow Delivery @ Various External Static Pressures (in. w.c.) UNIT LEAD- SPEED SIZE COLOR Gray 1230 1190 1155 1120 1080 1045 1010 Yellow Orange 0451412 Blue −− Gray 1185 1140 1095 1055...
Page 18 Table 6 – Maximum Capacity of Pipe* NOMINAL IRON INTERNAL LENGTH OF PIPE - FT. (M) PIPE DIAMETER SIZE IN. (mm) In. (mm) 1/2 (13) 0.622 (16) 175 (53) 120 (37) 97 (30) 82 (25) 73 (22) 3/4 (19) 0.824 (21) 360 (110) 250 (76) 200 (61)
Page 19 A02163 Fig. 20 − Downflow Return Air Configurations and Restrictions A02162 Fig. 21 − Horizontal Return Air Configurations and Restrictions 2” (51mm) Street Elbow A08551 Fig. 22 − Burner and Manifold 441 01 1421 02 Specifications are subject to change without notice.
Page 20: Electrical Connection
Table 7 – Electrical Data Operating Maximum Voltage* Range Volts− Minimum Maximum Fuse or FURNACE Maxi- Mini- Hertz− Maximum Unit Wire Size Wire Length‡ CKT BKR† MODEL Amps Phase Unit Amps Ampacity# ft (m) 0451412 115-60-1 14.0 47.0 (14.3) 15.0 0701712 115-60-1 14.0...
Page 21: Volt Wiring
NOTE: The J−Box cover need not be removed from the J−Box 4. Secure field ground wire to green ground screw on J−Box bracket. in order to move the J−Box. Do NOT remove green ground 5. Connect line voltage leads as shown in Fig. 25. screw inside J−Box.
Page 22 HEAT J2 JUMPER OFF DELAY TWINNING AND/OR COMPONENT TEST TERMINAL 24 V THERMOSTAT TERMINALS HUMIDIFIER TERMINAL 3 AMP FUSE (24 VAC 0.5 AMP MAX) TRANSFORMER 24 VAC CONNECTIONS LED OPERATION & DIAGNOSTIC LIGHT LOW VOLTAGE MAIN HARNESS CONNECTOR HOT SURFACE IGNITOR (HSI) BLOWER SPEED &...
Page 23: Venting
VENTING GENERAL VENTING REQUIREMENTS The furnace shall be connected to a listed factory built chimney Follow all safety codes for proper vent sizing and installation or vent, or a clay−tile lined masonry or concrete chimney. Venting requirements, including local building codes, the current edition into an unlined masonry chimney or concrete chimney is of National Fuel Gas Code ANSI Z223.1/NFPA 54 (NFGC), prohibited.
Page 24: Appliance Application Requirements
This furnace is permitted to be vented into a clay tile−lined Table 9 – Minimum Allowable Input Rating of Space−Heat- masonry chimney that is exposed to the outdoors below the roof ing Appliance in Thousands of BTUH per Hour line, provided: INTERNAL AREA OF CHIMNEY 1.
Page 25 CHIMNEY INSPECTION CHART For additional requirements refer to the National Fuel Gas Code NFPA 54/ANSI Z223.1 and ANSI/NFPA 211 Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances Crown Rebuild condition: crown. Missing mortar or brick? Is chimney property lined with clay tile liner? Repair Reline...
Page 26: Additional Venting Requirements
To prevent condensation in the furnace and vent system, the NOTE: An accessory flue extension is available to extend from following precautions must be observed: the furnace elbow to outside the furnace casing. See Specification Sheet for accessory listing. If flue extension is used, fasten the 1.
Page 27 Caution!! For the following applications, use the minimum vertical vent heights as specified below. For all other applications, follow exclusively the National Fuel Gas Code. MIN. VENT MIN. VERTICAL VENT FURNACE FURNACE INPUT VENT ORIENTATION DIAMETER HEIGHT ORIENTATION (BTUH/HR) IN (MM)* FT.
Page 28 SEE NOTES: 1,2,4,7,8,9 on the page following these figures SEE NOTES: 1,2,4,5,6,7,8,9 on the page following these figures A03207 A03213 Fig. 31 − Downflow Application−Vent Elbow Left then Up Fig. 33 − Horizontal Left Application−Vent Elbow Left SEE NOTES: 1,2,4,5,7,8,9 on the page following these figures SEE NOTES:1,2,3,4,5,7,8,9 on the page following...
Page 29 SEE NOTES: 1,2,4,7,8,9 on the page following these figures SEE NOTES: 1,2,4,5,7,8,9 on the page following these figures A03214 A03219 Fig. 35 − Horizontal Right Application−Vent Elbow Right Fig. 37 − Horizontal Right Application−Vent Elbow Left then Up SEE NOTES: 1,2,4,5,7,8,9 on the page SEE NOTES: 1,2,4,5,7,8,9 on the page following these figures following these figures...
Page 30: Start−Up, Adjustment, And Safety Check
START−UP, ADJUSTMENT, AND SAFETY WARNING CHECK General ELECTRICAL SHOCK HAZARD Failure to follow this warning could result in personal WARNING injury, or death. Blower access door switch opens 115−v power to control. FIRE HAZARD No component operation can occur unless switch is closed. Caution must be taken when manually closing this switch Failure to follow this warning could result in personal for service purposes.
Page 31 1. Determine the correct gas input rate. d. Turn gas valve ON/OFF switch to ON. The input rating for altitudes above 2,000 ft. (610 M) must e. Manually close blower door switch. be reduced by 4 percent for each 1,000 ft. (305 M) above f.
Page 32: Check Safety Controls
(3.) Return and supply ducts for excessive restrictions WARNING causing static pressures greater than 0.50−In. W.C. c. Adjust air temperature rise by adjusting blower speed. In- crease blower speed to reduce temperature rise. Decrease FIRE HAZARD blower speed to increase temperature rise Failure to follow this warning could result in personal d.
Page 33: Checklist
2. Check draft safeguard switch. THERMOSTAT SUBBASE TERMINALS WITH The purpose of this control is to cause the safe shutdown THERMOSTAT REMOVED of the furnace during certain blocked vent conditions. (ANITICIPATOR, CLOCK, ETC., MUST BE OUT OF CIRCUIT.) a. Verify vent pipe is cool to the touch. HOOK-AROUND b.
Page 34 Table 11 – Gas Rate (Cu Ft./Hr.) SIZE OF TEST DIAL SIZE OF TEST DIAL SECONDS SECONDS FOR 1 REVOLUTION FOR 1 REVOLUTION 2 Cu Ft. 5 Cu Ft. 1 Cu Ft. 2 Cu Ft. 5 Cu Ft. Cu Ft. 1800 1636 1500...
Page 35 Table 12 – Orifice Size* and Manifold Pressure (In. W.C.) for Gas Input Rate A10180 441 01 1421 02 Specifications are subject to change without notice.
Page 36 Table 12 − Orifice Size* and Manifold Pressure (In. W.C.) for Gas Input Rate (CONT) A10180A 441 01 1421 02 Specifications are subject to change without notice.
Page 37 Table 13 – Orifice Size* And Manifold Pressure (In. W.C.) For Gas Input Rate A10181 441 01 1421 02 Specifications are subject to change without notice.
Page 38 Table 13− Orifice Size* And Manifold Pressure (In. W.C.) For Gas Input Rate (CONT) A10181A 441 01 1421 02 Specifications are subject to change without notice.
Page 39: Service And Maintenance Procedures
SERVICE AND MAINTENANCE INTRODUCTION PROCEDURES GENERAL These instructions are written as if the furnace is installed in an Untrained personnel can perform basic maintenance functions upflow application. An upflow furnace application is where the such as cleaning and replacing air filters. All other operations blower is located below the combustion and controls section of must be performed by trained service personnel.
Page 40: Care And Maintenance
Fig. 43 − Service Label CARE AND MAINTENANCE WARNING WARNING CARBON MONOXIDE POISONING AND FIRE HAZARD FIRE OR EXPLOSION HAZARD Failure to follow this warning could result in personal Failure to follow this warning could result in personal injury, death and/or property damage. injury, death and/or property damage.
Page 41: Cleaning And/Or Replacing Filter
CLEANING AND/OR REPLACING AIR FILTER 9. If a greasy residue is present on blower wheel, remove wheel from the blower housing and wash it with an appro- The air filter arrangement will vary depending on the application. priate degreaser. To remove wheel: The filter is exterior to the furnace casing.
Page 42: Cleaning Heat Exchanger
NOTE: If thermostat terminals are jumpered at the time blower NOTE: Be very careful when removing burner assembly to access door switch is closed, blower will run for 90 sec before avoid breaking igniter. See Fig. 44 and 45 for correct igniter beginning a heating or cooling cycle.
Page 43: Sequence Of Operation
(6.) Using vacuum cleaner, remove residue from each WARNING cell. (7.) Using vacuum cleaner with soft brush attachment, clean burner assembly. FIRE OR EXPLOSION HAZARD (8.) Clean flame sensor with fine steel wool. Failure to follow this warning could result in personal injury, death and/or property damage.
Page 44: Wiring Diagrams
nace, or by interrupting 24 vac power at 24VAC or (25 sec), allowing the furnace heat exchangers to heat up COM to the furnace control CPU (not at W, G, R, etc.) more quickly, then restarts at the end of the blower−ON If flame is proved when flame should not be present, delay period at HEAT speed.
Page 45 Fig. 47 − Wiring Diagram 441 01 1421 02 Specifications are subject to change without notice.
Page 46 441 01 1421 02 Specifications are subject to change without notice.
Page 47 Fig. 48 − Troubleshooting Guide 441 01 1421 02 Specifications are subject to change without notice.
Page 48: Parts Replacement Information Guide
The qualified installer or service agency must use only facto- ry−authorized replacement parts, kits, or accessories when modifying this product. Copyright 2017 International Comfort Products Lewisburg, TN 37091 USA 441 01 1421 02 Specifications are subject to change without notice.

International comfort products N8MXL Installation Instructions Manual

Quick Links

Related Manuals for International comfort products N8MXL

Summary of Contents for International comfort products N8MXL

Table of Contents