INSTALLATION INSTRUCTIONS A97USMV Warm Air Gas Furnace Upflow/Horizontal Left and Right Air Discharge This manual must be left with the homeowner for future reference. This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to the potential for personal injury or death. CAUTION NOTICE A thermostat is not included and must be ordered separately. • A Comfort SyncTM thermostat must be used in communicating applications.
Unit Dimensions - inches (mm) * NOTE - C/D20 size units that require second stage air volumes over 1800 cfm (850 L/S) must have one of the following: 1. Single side return air with transition, to accommodate 20 x 25 x 1 in. (508 x 635 x 25 mm) air filter. 2. Single side return air with optional RAB Return Air Base 3. Bottom return air. 4. Return air from both sides. 5. Bottom and one side return air. See Blower Performance Tables for additional information.
A97USMV Exploded View Figure 1 506887-01 Issue 1213 Page 3 of 78
A97USMV Gas Furnace The A97USMV Category IV gas furnace is equipped with a variable capacity, variable speed integrated control. Each A97USMV is shipped ready for installation in the upflow, horizontal left air discharge or horizontal right air discharge position. Safety Information DANGER DANGER OF EXPLOSION! There are circumstances in which odorant used with LP/ Propane gas can lose its scent. In case of a leak, LP/ Propane gas will settle close to the floor and may be difficult to smell.
For installation in a residential garage, the furnace must be installed so that the burner(s) and the ignition source are located no less than 18 inches (457 mm) above the floor. The furnace must be located or protected to avoid physical damage by vehicles. When a furnace is installed in a public garage, hangar, or other building that has a hazardous atmosphere, the furnace must be installed according to recommended good practice requirements and current National Fuel Gas Code or CSA B149 standards.
• Air filters must be replaced upon construction completion. • • When the furnace is installed in an attic or other insulated space, keep insulation away from the furnace. The input rate and temperature rise must be set per the furnace rating plate. • When the furnace is installed in an unconditioned space, consider provisions required to prevent freezing of condensate drain system. • One hundred percent (100%) outdoor air must be provided for combustion air requirements during construction.
SETTING EQUIPMENT UNIT MUST BE LEVEL SIDE TO SIDE IN ALL APPLICATIONS FOR PROPER OPERATION. A SLIGHT TILT TOWARD THE DRAIN IS RECOMMENDED FOR PROPER DRAINAGE. TILT THE UNIT SLIGHTLY (MAX. 1/2”) FROM BACK TO FRONT TO AID IN THE DRAINING OF THE HEAT EXCHANGER.
Removing the Bottom Panel Remove the two screws that secure the bottom cap to the furnace. Pivot the bottom cap down to release the bottom panel. Once the bottom panel has been removed, reinstall the bottom cap. See Figure 7.
NOTE: Units with 1/2 hp blower motor are equipped with three flexible legs and one rigid leg. The rigid leg is equipped with a shipping bolt and a flat white plastic washer (rather than the rubber mounting grommet used with a flexible mounting leg). See Figure 9. The bolt and washer must be removed before the furnace is placed into operation. After the bolt and washer have been removed, the rigid leg will not touch the blower housing.
Setting and Upflow Unit When the side return air inlets are used in an upflow application, it may be necessary to install shims on the bottom of the furnace. Horizontal Applications The A97USMV furnace can be installed in horizontal applications with either right or left hand air discharge. Refer to Figure 11 for clearances in horizontal applications. NOTE: Heavy gauge sheet metal straps may be used to suspend the unit from roof rafters or ceiling joists.
Duct System Use industry approved standards to size and install the supply and return air duct system. This will result in a quiet and low static system that has uniform air distribution. NOTE: Operation of this furnace in heating mode (indoor blower operating at selected heating speed) with an external static pressure which exceeds 0.8 inches w.c. may result in erratic limit operation.
Pipe and Fittings Specifications All pipe, fittings, primer and solvent cement must conform with American National Standard Institute and the American Society for Testing and Materials (ANSI/ASTM) standards. The solvent shall be free flowing and contain no lumps, undissolved particles or any foreign matter that adversely affects the joint strength or chemical resistance of the cement. The cement shall show no gelation, stratification, or separation that cannot be removed by stirring.
OUTDOOR TERMINATION KITS USAGE Table 3 Joint Cementing Procedure All cementing of joints should be done according to the specifications outlined in ASTM D2855. DANGER NOTE: Time is critical at this stage. Do not allow primer to dry before applying cement. DANGER OF EXPLOSION! Fumes from PVC glue may ignite during system check. Allow fumes to dissipate for at least 5 minutes before placing unit into operation. 1. Measure and cut vent pipe to desired length. 2.
Venting Practices Piping Suspension Guidelines 1. In areas where piping penetrates joist or interior walls, hole must be large enough to allow clearance on all sides of pipe through center of hole using a hanger. 2. When furnace is installed in a residence where unit is shut down for an extended period of time, such as a vacation home, make provisions for draining condensate collection from trap and lines.
2. Inspect the venting system for proper size and horizontal pitch. Determine that there is no blockage, restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition. 3. Close all building doors and windows and all doors between the space in which the appliances remaining connected to the common venting system are located and other spaces of the building. Turn ON clothes dryers and any appliances not connected to the common venting system.
Figure 17 Page 16 of 78 Issue 1213 506887-01
Maximum Allowable Intake or Exhaust Vent Length (feet) *Size intake Exhaust not and exhaust pipe length separately. Values in combined total. Both Intake and Exhaust must table are be same for pipe Intake size.
TYPICAL EXHAUST AND INTAKE PIPE CONNECTIONS IN UPFLOW APPLICATIONS * When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible. Figure 18 TYPICAL EXHAUST AND INTAKE PIPE CONNECTIONS IN HORIZONTAL APPLICATIONS (RIGHT HAND DISCHARGE SHOWN) * When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
VENT TERMINATION CLEARANCES FOR DIRECT VENT INSTALLATiONS IN THE USA AND CANADA Figure 20 506887-01 Issue 1213 Page 19 of 78
General Guidelines for Vent Terminations In Direct Vent applications, combustion air is taken from outdoors and the flue gases are discharged to the outdoors. This gas furnace is classified as a direct vent, Category IV gas furnace. In Direct Vent applications, the vent termination is limited by local building codes. In the absence of local codes, refer to the current National Fuel Gas Code ANSI Z223-1/NFPA 54 in U.S.A., and current CSA-B149 Natural Gas and Propane Installation Codes in Canada for details.
Details of Intake and Exhaust Piping Terminations for Direct Vent Installations NOTE: In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged to outdoors. Intake and exhaust pipes may be routed either horizontally through and outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof is preferred. Figures 23 through 29 show typical terminations. 1.
FIELD SUPPLIED WALL TERMINATION OR See venting Table 5 for maximum venting lengths with this arrangement. * Use wall support every 24” (610 mm). Use two wall supports if extension is greater than 24” (610 mm) but less than 48” (1219 mm).
EXHAUST PIPE TERMINATION SIZE REDUCTION FIELD SUPPLIED WALL TERMINATION with INTAKE ELBOW * 070 and 090 units installed with flush mount termination must use the 1-1/ 2” accelerator supplied with the kit. Table 7 5. On field supplied terminations for sidewall exit, exhaust piping may extend a maximum of 12 inches (305 mm) for 2” PVC and 20 inches (508 mm) for 3” (76 mm) PVC beyond the outside wall. Intake piping should be as short as possible. See Figures 22 and 23. 6.
DIRECT VENT CONCENTRIC WAL TERMINATION 71M80, 69M29 OR 60L46 (US) 44W92 or 44W93 (Canada) FLUSH-MOUNT SIDE WALL TERMINATION 51W11 Figure 27 Figure 28 Figure 29 Page 24 of 78 Issue 1213 506887-01
DIRECT VENT APPLICATION USING EXISTING CHIMNEY NOTE: Do not discharge exhaust gases directly into any chimney or vent stack. If vertical discharge through an existing unused chimney or stack is required, insert piping inside chimney until the pipe open end is above top of chimney and terminates as illustrated. In any exterior portion of chimney, the exhaust vent must be insulated.
Figure 32 A97USMV With Evaporator Coil Using a Separate Drain Furnace Figure 33 Evaporator Coil Using A Separate Drain CAUTION A separate drain line must be run to the drain from the condensate trap. DO NOT connect the condensate trap drain into the drain line from the evaporator coil.
Evaporator Coil using a Common Drain IMPORTANT When combining the furnace and evaporator coil drains together, the A/C condensate drain outlet must be vented to relieve pressure in order for the furnace pressure switch to operate properly.
Trap / Drain Assembly using 1/2” PVC or 3/4” PVC Figure 38 Page 28 of 78 Issue 1213 506887-01
Gas Piping IMPORTANT CAUTION Compounds used on threaded joints of gas piping must be resistant to the actions of liquified petroleum gases. If a flexible gas connector is required or allowed by the authority that has jurisdiction, black iron pipe shall be installed at the gas valve and extend outside the furnace cabinet. The flexible connector can then be added between the black iron pipe and the gas supply line. WARNING Do not exceed 600 in.-lbs. (50 ft.-lbs.
NOTE: BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET Figure 36 Horizontal Applications Possible Gas Piping Configurations NOTE: BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET Figure 37 Page 30 of 78 Issue 1213 506887-01
GAS PIPE CAPACITY - FT³/HR (kL/HR) 1 NOTE: Capacity given in cubic feet of gas per hour (kilo liters of gas per hour) and based on 0.60 specific gravity gas.
Electrical ELECTROSTATIC DISCHARGE (ESD) Precautions and Procedures CAUTION Electrostatic discharge can affect electronic components. Take precautions during furnace installation and service to protect the furnace’s electronic controls. Precautions will help to avoid control exposure to electrostatic discharge by putting the furnace, the control and the technician at the same electrostatic potential.
8. One line voltage “HUM” 1/4” spade terminal is provided on the furnace integrated control. Any humidifier or other 120V accessory rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to one of the provided neutral terminals. See Figure 41 for location of terminal. This terminal is energized in the heating mode when the indoor blower is operating. 9. One 24V “H” terminal is provided on the furnace integrated control terminal block.
Typical A97USMV Field Wiring Diagram for Standard Non-Communicating Thermostat Figure 44 Page 34 of 78 Issue 1213 506887-01
506887-01 Issue 1213 Page 35 of 78
Figure 46 Page 36 of 78 Issue 1213 506887-01
Field Wiring Connections for Non-Communicating Thermostat Applications D IP S w itch S ettin g s an d O n -B o ard L in ks (fig u re N O T AG ) D IP S w itch 1 T h erm o stat 1H eat / 1 C oo l N O T E - U se D IP sw itch 3 to set second-stage heat O N de lay. O F F -7 m in utes. O N -12 m inutes. ON 1 H ea t / 2 C oo l N O T E - U se D IP sw itch 3 to set second-stage heat O N de lay. O F F -7 m in utes. O N -12 m inutes.
Field Wiring for Non-Communicating Applications (continued) D IP S w itch S ettin g s an d O n -B o ard L in ks (fig u re N O T AG ) D IP S w itch 1 T h erm o stat 2 H ea t / 2 C oo l OFF W 915 (Y 1 to Y 2) T w o-S tag e C o o lin g W 914 (D S to R ) D eh u m id ific atio n o r H arm o n y III£ W 951 (O to R ) H eat P u m p s C ut Intact Intact W irin g C o n n ectio n s S1 T’STAT CONTROL TERM.
506887-01 Issue 1213 Page 39 of 78
Typical A97USMV Wiring Diagram Figure 47 Page 40 of 78 Issue 1213 506887-01
Integrated Control Figure 48 506887-01 Issue 1213 Page 41 of 78
Low Voltage Field Wiring Single Stage 2 Stage Table 14 Page 42 of 78 Issue 1213 506887-01
Thermostat Selection Switch Settings Table 15 NOTE - When this furnace is used with a Comfort SyncTM communicating thermostat, all indoor blower speed selections and DIP switch settings are made by the communicating thermostat. These units are equipped with an integrated control. This control manages ignition timing, combustion air inducer speed, heating mode fan OFF delays and indoor blower speeds based on selections made using the control DIP switches and onboard links.
Switches 8 and 9 - Cooling Mode Blower SpeedThe unit is shipped from the factory with the DIP switches positioned for high speed (4) indoor blower motor operation during the cooling mode. The table below provides the cooling mode blower speeds that will result from different switch settings.
Switches 14 through 19 - Heating Mode Blower Speed These switches are factory set at the OFF position which provides 100% of normal speed during HIGH HEAT demand, 70% of normal speed during MIDRANGE HEAT demand and 40% of normal speed during LOW HEAT demand. Switches 14, 15 and 16 are used to adjust the LOW HEAT blower motor speed. Switches 17, 18 and 19 are used to adjust the HIGH HEAT blower motor speed. Table 18 provides the heating mode blower speeds that will result from different switch settings.
BLOWER DATA Page 46 of 78 Issue 1213 506887-01
BLOWER DATA 506887-01 Issue 1213 Page 47 of 78
BLOWER DATA Page 48 of 78 Issue 1213 506887-01
BLOWER DATA 506887-01 Issue 1213 Page 49 of 78
BLOWER DATA Page 50 of 78 Issue 1213 506887-01
BLOWER DATA 506887-01 Issue 1213 Page 51 of 78
BLOWER DATA Page 52 of 78 Issue 1213 506887-01
BLOWER DATA 506887-01 Issue 1213 Page 53 of 78
BLOWER DATA Page 54 of 78 Issue 1213 506887-01
TABLE 22 506887-01 Issue 1213 Page 55 of 78
TABLE 23 Page 56 of 78 Issue 1213 506887-01
Unit Start Up BEFORE PLACING THE UNIT INTO OPERATION Smell all around the furnace area for gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor. FOR YOUR SAFETY READ BEFORE OPERATING WARNING The gas valve on these units are equipped with a gas control switch. Use only your hand to move the control switch. Never use tools. If the switch will not move by hand, do not try to repair it. Force or attempted repair may result in a fire or explosion.
9. Replace the access panel. 10. Turn on all electrical power to the unit. 11. Set the thermostat to desired setting. NOTE: To obtain accurate reading, shut off all other gas appliances connected to meter. NOTE: When unit is initially started, steps 1 through 11 may need to be repeated to purge air from gas line. 12. If the Appliance will not operate, follow the instructions “Turning Off Gas to Unit” and call the gas supplier. Turning Off Gas to Unit 1. Set the thermostat to the lowest settling. 2.
Table 25 NOTE - A natural to LP/propane gas changeover kit (table 24) is necessary to convert this unit. Refer to the changeover kit installation instructions for the conversion procedure. High Altitude Information NOTE: In Canada,certification for installationa at elevations over 4500 feet (1372 m) is the jurisidiction of local authorities. These units require no manifold pressure adjustments for operation at altitudes up to 7,500 feet (2286 m) above sea level.
Figure 50 Page 60 of 78 Issue 1213 506887-01
Other Unit Adjustments Primary Limit The primary limit is located on the heating compartment vestibule panel. This limit is factory set and requires no adjustment. Flame Rollout Switches (Two) These manually reset switches are located on the inside of the burner box. If tripped, check for adequate combustion air before resetting. Pressure Switches (Two) The pressure switches are located on the cold end header box.
Heating Sequence of Operation The integrated control initiates a pressure switch calibration at the initial unit start-up on a call for heat. The ignition control will also initiate a calibration any time main power is turned off and back on and a heating demand is present. Additional calibrations may be initiated by the service technician during field test sequence. The following heating sequence of operation assumes completion of a successful calibration.
5. If second-stage heat is required, the thermostat second stage heat contacts close and send a signal to the integrated control. The integrated control either increases the firing rate to 70 percent (if the current rate is at or below 60 percent) or increases the firing rate by 10 percent (if the current rate is above 60 percent).
3. Check amp-draw on the blower motor with the blower access panel in place. Motor Nameplate_____________ Actual___________ Service WARNING Winterizing and Condensate Trap Care 1. Turn off power to the unit. 2. Have a shallow pan ready to empty condensate water. 3. Remove the drain cap from the condensate trap and empty water. Inspect the trap then reinstall the drain cap. ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD.
18. Remove screws along vestibule sides and bottom which secure vestibule panel and heat exchanger assembly to cabinet. Remove two screws from blower rail which secure bottom heat exchanger flange. Remove heat exchanger from furnace cabinet. 19. Back wash heat exchanger with soapy water solution or steam. If steam is used it must be below 275°F (135°C). 20. Thoroughly rinse and drain the heat exchanger. Soap solutions can be corrosive. Take care to rinse entire assembly. 21.
Planned Service Return air duct - Must be properly attached and provide an air seal to the unit. A service technician should check the following items during an annual inspection. Power to the unit must be shut off for the service technician's safety. Operating performance - Unit must be observed during operation to monitor proper performance of the unit and the vent system. Burners - Must be inspected for rust, dirt, or signs of water.
Integrated Control Diagnostic Codes Press the diagnostic push button and hold it to cycle through a menu of options. Every five seconds a new menu item will be displayed. Release the button when the desired mode is displayed. When a solid "P" is displayed, the furnace capacity/ size can be programmed. When the solid "E" is displayed, the control enters the Error Code Recall mode.
Page 68 of 78 Issue 1213 506887-01
506887-01 Issue 1213 Page 69 of 78
Page 70 of 78 Issue 1213 506887-01
Troubleshooting: Heating Sequence of Operation Ignition and Call for Low Fire With Two Stage Thermostat 506887-01 Issue 1213 Page 71 of 78
Troubleshooting : Heating Sequence of Operation (continued) Call for High Fire With Two Stage Thermostat Page 72 of 78 Issue 1213 506887-01
Troubleshooting : Heating Sequence of Operation (continued) Call for Heat Satisfied 506887-01 Issue 1213 Page 73 of 78
Troubleshooting : Heating Sequence of Operation (continued) Ignition and Call for Heat with Single Stage Thermostat Page 74 of 78 Issue 1213 506887-01
Troubleshooting : Cooling Sequence of Operation Call for Cooling 506887-01 Issue 1213 Page 75 of 78
Troubleshooting : Continuous Fan Sequence of Operation Continuous Low Speed Indoor Blower Sequence of Operation Page 76 of 78 Issue 1213 506887-01
REPAIR PARTS LIST The following repair parts are available through Allied Air distributors. When ordering parts, include the complete furnace model number listed on the nameplate. All service must be performed by a licensed professional installer (or equivalent), service agency, or gas supplier.
REQUIREMENTS for COMMONWEALTH of MASSACHUSETTS Modifications to NFPA-54, Chapter 10 Revise NFPA-54 section 10.8.
