Page 1: Table Of Contents
........ML193DF Parts Arrangement .....
Page 2: Unit Dimensions
ML193DF Unit Dimensions − inches (mm) 9/16 (14) COMBUSTION AIR INTAKE RETURN AIR OPENING EXHAUST AIR OUTLET 2−1/16 (52) 2−1/4 9/16 (57) (14) (127) TOP VIEW 27−3/4 1 (25) Front Panel (705) 9/16 19−7/16 9/16 (494) (14) (14) FLOW ELECTRICAL INLET...
Page 3: Ml193Df Parts Arrangement
ML193DF Parts Arrangement CONTROL BOX (Includes integrated control, transformer and door switch) BAG ASSEMBLY BLOWER MOTOR (hidden) BLOWER ACCESS PANEL COMBUSTION AIR INDUCER BLOWER DECK PRIMARY LIMIT BURNER ACCESS COLD END HEADER BOX PANEL HEAT EXCHANGER GAS VALVE BURNER BOX ASSEMBLY...
Page 4: Ml193Df Gas Furnace
A conversion kit (ordered separately) is re- Safety Information quired for use in propane/LP gas applications. The ML193DF can be installed as a Direct Vent or Non− WARNING Direct Vent gas central furnace. NOTE − In Direct Vent installations, combustion air is taken Improper installation, adjustment, alteration, service from outdoors and flue gases are discharged outdoors.
Page 5: Use Of Furnace As Construction Heater
85°F (29°C) dry bulb. exchanger failure. The ML193DF furnace may be installed in alcoves, closets, This ML193DF furnace must be installed so that its electri- attics, basements, garages, utility rooms and crawl cal components are protected from water.
Page 6: General
In Canada, refer to the CSA B149 installation codes. Combustion, Dilution & Ventilation Air If the ML193DF is installed as a Non−Direct Vent Fur- CAUTION nace, follow the guidelines in this section. NOTE − In Non−Direct Vent installations, combustion air Do not install the furnace in a corrosive or contami- is taken from indoors and flue gases are discharged out−...
Page 7 All gas-fired appliances require air for the combustion pro- dangerous negative pressure condition. Air for combustion cess. If sufficient combustion air is not available, the fur- and ventilation can be brought into the confined space ei- nace or other appliance will operate inefficiently and un- ther from inside the building or from outside.
Page 8 EQUIPMENT IN CONFINED SPACE − ALL AIR FROM OUTSIDE EQUIPMENT IN CONFINED SPACE − ALL AIR FROM OUTSIDE (Inlet Air from Crawl Space and Outlet Air to Ventilated Attic) (All Air Through Ventilated Attic) VENTILATION LOUVERS (Each end of attic) ROOF TERMINATED VENTILATION LOUVERS ROOF TERMINATED...
Page 9: Setting Equipment
Allow for clearances to combustible materials as indicated ML193DF09048C BLOWER MOTOR on the unit nameplate. Minimum clearances for closet or al- RIGID LEG remove shipping bolt and washer cove installations are shown in figure 11. WARNING Blower access panel must be securely in place when blower and burners are operating.
Page 10 Installation on Non−Combustible Flooring Figure 12 WARNING 1 − Cut floor opening keeping in mind clearances listed on Improper installation of the furnace can result in per- unit rating plate. Also keep in mind gas supply connec- sonal injury or death. Combustion and flue products tions, electrical supply, flue and air intake connections must never be allowed to enter the return air system and sufficient installation and servicing clearances.
Page 11 TABLE 2 COMBUSTIBLE FLOORING BASE OPENING SIZE Front to Rear Side to Side Cabinet Catalog FURNACE Width Number B Cabinet 11M60 18 − 3/4 (17.5") C Cabinet COOLING COIL 11M61 22 − 3/4 (21") PROPERLY SIZED FLOOR OPENING PLENUM FURNACE SUPPLY AIR PLENUM PROPERLY...
Page 12: Filters
Filters Pipe & Fittings Specifications All pipe, fittings, primer and solvent cement must conform This unit is not equipped with a filter or rack. A field−pro- with American National Standard Institute and the Ameri- vided filter is required for the unit to operate properly. Table can Society for Testing and Materials (ANSI/ASTM) stan- 3 lists recommended filter size.
Page 13 *Requires field−provided and installed 1−1/2" exhaust accelerator. ** Kit 51W11 is provided with a 1−1/2" accelerator which must be used for all ML193DF−045, −070 and −090 installations. † Termination kits 44W92, 44W93, 30G28 and 81J20 approved for use in Canadian installations to meet CSAB149.
Page 14: Joint Cementing Procedure
DO NOT turn ABS or cellular core pipe. If an ML193DF furnace replaces a furnace which was com- NOTE − Assembly should be completed within 20 sec- monly vented with another gas appliance, the size of the ex- isting vent pipe for that gas appliance must be checked.
Page 15: Vent Piping Guidelines
Vent Piping Guidelines How many? The ML193DF can be installed as either a Non−Direct Vent or a Direct Vent gas central furnace. NOTE − In Non-Direct Vent installations, combustion air is taken from indoors and flue gases are discharged outdoors.
Page 16 TABLE 7 Maximum Allowable Intake or Exhaust Vent Length in Feet *Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake and Exhaust must be same pipe size. Standard Termination at Elevation 0 − 10,000 ft. 2"...
Page 17 TYPICAL EXHAUST PIPE CONNECTIONS Pipe size determined in table 7. 2” 2” 2” 2” 2” 3” TRANSITION INTAKE DO NOT transition from smaller EXHAUST *2” to larger pipe size in horizontal TOP VIEW runs of exhaust pipe. * When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible. NOTE −...
Page 18 Ventilation Air section must be followed. doors. The ML193DF is then classified as a direct vent, Follow the next two steps when installing the unit in Direct Category IV gas furnace.
Page 19: Vent Termination Clearances
VENT TERMINATION CLEARANCES FOR NON−DIRECT VENT INSTALLATIONS IN THE USA AND CANADA INSIDE CORNER DETAIL Fixed Operable Fixed Closed Closed Operable AREA WHERE TERMINAL AIR SUPPLY INLET VENT TERMINAL IS NOT PERMITTED US Installations Canadian Installations Clearance above grade, veranda, 12 inches (305mm) or 12 in.
Page 20 VENT TERMINATION CLEARANCES FOR DIRECT VENT INSTALLATIONS IN THE USA AND CANADA INSIDE CORNER DETAIL Fixed Operable Fixed Closed Closed Operable AREA WHERE TERMINAL AIR SUPPLY INLET VENT TERMINAL IS NOT PERMITTED US Installations Canadian Installations Clearance above grade, veranda, 12 inches (305mm) or 12 in.
Page 21 (610mm) as shown in figures 28 and 29. In addition, 2" (51mm) close coupled wall termination kits must be extended *ML193DF−045, −070 and −090 units with the flush−mount termination for use in this application. See figures 35 and 36. must use the 1−1/2"accelerator supplied with the kit.
Page 22 Intake Front View of Intake and Exhaust Exhaust Intake Exhaust TABLE 9 2" (51mm) 3" (76mm) Vent Pipe Vent Pipe A− Clearance above grade or average snow 12" (508MM) Min. 12" (508MM) Min. accumulation 12" B−Horizontal 6" (152MM) Min. 6" (152MM) Min. separation between 24"...
Page 23 FIELD SUPPLIED WALL TERMINATION OR FIELD SUPPLIED WALL TERMINATION OR (15F74) WALL RING TERMINATION KIT (15F74) WALL RING TERMINATION KIT With INTAKE ELBOW NOTE − FIELD PROVIDED NOTE − FIELD PROVIDED REDUCER MAY BE REDUCER MAY BE 1/2" (13mm) ARMAFLEX 1/2"...
Page 24 1−1/2" (38mm) accelerator EXHAUST VENT Front View provided on 71M80 & 44W92 kits for ML193DF045P36B− & SIZE 070P36B TERMINATION PIPE PER INTAKE FLASHING TABLE 8. 12” (305mm) (Not Furnished) INTAKE Minimum Above Average Snow Accumulation Top View 1/2" (13mm) Foam Insulation in Unconditioned Space SHEET METAL STRAP (Clamp and sheet metal strap...
Page 25 WALL TERMINATION KITS (CLOSE−COUPLE) EXTENDED VENT FOR GRADE CLEARANCE 2 inch (51 mm) 22G44 (US) 3 inch (76 mm) 44J40 (US) If intake and exhause pipe is less than 12 in. (305 mm) above snow accumulation or other obstructions, field− fabricated piping must be installed.
Page 26 ML193DF DIRECT VENT APPLICATION SIZE TERMINATION STRAIGHT−CUT OR USING EXISTING CHIMNEY ANGLE−CUT IN DIRECTION PIPE PER TABLE 8. OF ROOF SLOPE * 12" (305mm) ABOVE AVE. SNOW 1/2" (13mm) FOAM 8" − 12" 3" − 8" EXHAUST VENT ACCUMULATION (76mm−...
Page 27 1−1/2 in. (same on left NON−DIRECT VENT FIELD SUPPLIED WALL TERMINATION EX- side) TENDED OR (15F74) WALL TERMINATION VENT PIPE EXTENDED FIGURE 40 ML193DF NON−DIRECT VENT APPLICATION USING EXISTING CHIMNEY SIZE TERMINATION STRAIGHT−CUT OR ANGLE−CUT IN DIRECTION PIPE PER TABLE 8.
Page 28 5 − If unit will be started immediately upon completion of ML193DF with Evaporator Coil installation, prime trap per procedure outlined in Unit Start−Up section. Condensate line must slope downward away from the Condensate trap and Field−Provided Vent trap to drain. If drain level is above condensate trap, evaporator coil must drain separately as shown.
Page 29 TRAP / DRAIN ASSEMBLY USING 1/2" PVC OR 3/4" PVC OPTIONAL Condensate Drain Connection Adapter 1/2 inch slip X Adapter 1/2 inch slip X 1/2 inch mpt (Not Furnished) Condensate Drain 1/2 inch mpt (Not Furnished) Connection In Unit Vent 90°...
Page 30: Gas Piping
Gas Piping IMPORTANT Compounds used on threaded joints of gas piping CAUTION must be resistant to the actions of liquified petro- leum gases. If a flexible gas connector is required or allowed by the authority that has jurisdiction, black iron pipe Leak Check shall be installed at the gas valve and extend outside After gas piping is completed, carefully check all piping...
Page 31 Left Side Piping MANUAL AUTOMATIC (Standard) MAIN SHUT−OFF GAS VALVE MANUAL VALVE AUTOMATIC (with manual MAIN SHUT−OFF Plug (With 1/8 in. NPT GAS VALVE shut−off valve) VALVE Plugged Tap (with manual Plug (With 1/8 in. NPT Shown) shut−off valve) Plugged Tap Shown) GROUND JOINT UNION...
Page 32: Electrical
Removal of the Furnace from Common Vent 5 − After the main burner has operated for 5 minutes, test for leaks of flue gases at the draft hood relief opening. In the event that an existing furnace is removed from a Use the flame of a match or candle.
Page 33 CABINET C22.1) for Canada. A green ground wire is provided in the field make−up box. NOTE − The ML193DF furnace contains electronic compo- nents that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.
Page 34 HEAT when there is no cooling or heating demand. CONDENSING UNIT 2 − When the ML193DF is running in the heating mode, COOLING the indoor blower will run on the heating speed. INDOOR BLOWER CONDENSING 3 −...
Page 35 TYPICAL ML193DF WIRING DIAGRAM FIGURE 52 Page 35...
Page 36: Unit Start Up
CAUTION The gas valve on the ML193DF is equipped with a gas control switch. Use only your hand to move switch. Never Before attempting to perform any service or mainte- use tools. If the switch will not move by hand, do not try to nance, turn the electrical power to unit OFF at dis- repair it.
Page 37 Placing the furnace into operation: MANIFOLD MANIFOLD PRESSURE ML193DF units are equipped with an automatic hot sur- PRESSURE ADJUSTMENT face ignition system. Do not attempt to manually light OUTLET SCREW burners on this furnace. Each time the thermostat calls for heat, the burners will automatically light. The ignitor does not get hot when there is no call for heat on these units.
Page 38: Gas Pressure Measurement
4500 feet (1372 m) is the jurisdiction of local au- TABLE 12 thorities. Manifold and Supply Pressure (Outlet) inches w.c. ML193DF units require no manifold pressure adjustments Supply Model for operation at altitudes up to 10,000 feet (3048 m) above Manifold Pressure in.wg.
Page 39: Testing Non Direct Appliances For Proper Air
6 − Follow the lighting instruction to place the appliance nected to the venting system are not in operation. being inspected into operation. Adjust thermostat so After the ML193DF gas furnace has been started, the fol- appliance will operate continuously. lowing test should be conducted to ensure proper venting 7 −...
Page 40: Other Unit Adjustments
Other Unit Adjustments HEAT FAN-OFF TIME IN SECONDS NOTE − See troubleshooting flow charts if any safety switches are found to be open. Primary Limit The primary limit is located on the heating compartment NO JUMPER vestibule panel. This limit is factory set and requires no ad- To adjust fan−off timing, reposition jumper across pins to justment.
Page 41: Blower Motor Performance
BLOWER DATA ML193DF045P36B PERFORMANCE (Less Filter) ML193DF090P48C PERFORMANCE (Less Filter) Air Volume / Watts at Various Blower Speeds Air Volume / Watts at Various Blower Speeds External External Static Medium- Medium- Static Medium- Medium- High High Pressure High Pressure High in.
Page 42: Service
3 − Remove the clean out cap from the condensate trap Service and empty water. Inspect the trap then reinstall the drain plug. WARNING Cleaning Heat Exchanger If cleaning the heat exchanger becomes necessary, follow ELECTRICAL SHOCK, FIRE, the below procedures and refer to figure 1 when disassem- OR EXPLOSION HAZARD.
Page 43 19 − Reinstall heat exchanger into cabinet making sure that 38 − Follow lighting instructions to light and operate fur- the clamshells of the heat exchanger assembly are nace for 5 minutes to ensure that heat exchanger is resting on the support located at the rear of the cabi- clean and dry and that furnace is operating properly.
Page 44: Planned Service
Return air duct − Must be properly attached and provide Planned Service an air seal to the unit. A service technician should check the following items dur- Operating performance − Unit must be observed during ing an annual inspection. Power to the unit must be shut off operation to monitor proper performance of the unit and the for safety.
Page 45: Troubleshooting
Troubleshooting: Heating Sequence of Operation HEATING SEQUENCE OF OPERATION ABNORMAL HEATING MODE NORMAL HEATING MODE POWER ON GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER DELAY OFF. CONTROL SELF−CHECK OKAY? LED #1 ON LED #2 ON (RESET CONTROL BY TURNING MAIN POWER OFF.) POLARITY REVERSED.
Page 46 Troubleshooting: Heating Sequence of Operation (Continued) HEATING SEQUENCE CONTINUED NORMAL HEATING MODE ABNORMAL HEATING MODE 15-SECOND COMBUSTION AIR INDUCER PREPURGE INITIATED BY CLOSED PRESSURE SWITCH. LEDS SIGNAL ALTERNATING FAST FLASH UNTIL IGNITOR WARM-UP −− 20 SECONDS. IS VOLTAGE ABOVE 90 VOLTS? VOLTAGE IS ABOVE 95 VOLTS, THEN RESTARTS HEATING...
Page 47: Troubleshooting: Cooling Sequence Of Operation
Troubleshooting: Cooling Sequence of Operation COOLING SEQUENCE OF OPERATION NORMAL COOLING MODE ABNORMAL COOLING MODE POWER ON IGNITION CONTROL MAIN POWER ON. GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER OFF WITH NORMAL DELAY. CONTROL SELF DIAGNOSTIC CHECK. SIGNAL CIRCUIT BOARD FAILURE AT LED. IS CONTROL OPERATING NORMALLY? INTERRUPT MAIN POWER TO RESET CONTROL.
Page 48 Troubleshooting: Continuous Fan Sequence of Operation CONTINUOUS HEAT SPEED FAN SEQUENCE OF OPERATION LED: SLOW FLASH RATE REMAINS UNCHANGED THROUGHOUT SEQUENCE. MANUAL FAN SELECTION MADE AT THERMOSTAT. CONTROL (G) ENERGIZES SYSTEM FAN AT HEAT SPEED. EAC TERMINAL IS ENERGIZED. HUM TERM. ENERGIZES THERMOSTAT CALLS FOR HEAT (W).
Page 49: Repair Parts List
Repair Parts List The following repair parts are available through Lennox dealers. When ordering parts, include the complete furnace model number listed on the CSA nameplate −− Example: ML193DF04536B. All service must be performed by a licensed pro- fessional installer (or equivalent), service agency, or gas supplier. Cabinet Parts Heating Parts Upper access panel...
Page 50: Start Up Checklist
Start−Up & Performance Check List UNIT SET UP Furnace: Model Number_______________ Serial Number_________________ SUPPLY Line Voltage GAS SUPPLY LP Propane Gas Natural Gas Piping Connections Tight Leak Tested Flter Supply Line Pressure W.C.________ RETURN AIR Gas Supply Pressure DUCT SYSTEM SUPPLY AIR DUCT Sealed Insulated (if necessary)
Page 51 UNIT OPERATION HEATING MODE COOLING MODE GAS MANIFOLD PRESSURE W.C._____ INDOOR BLOWER AMPS______ COMBUSTION SAMPLE CO CO PPM_______ TEMPERATURE DROP ______ Return Duct Temperature _________ INDOOR BLOWER AMPS______ Supply Duct Temperature _______ Temperature Drop = _________ TEMPERATURE RISE TOTAL EXTERNAL STATIC (dry coil) Supply Duct Temperature ________ Supply External Static _______ Return Duct Temperature...
Page 52 Requirements for Commonwealth of Massachusetts Modifications to NFPA−54, Chapter 10 4 − INSPECTION. The state or local gas inspector of the side wall, horizontally vented, gas−fueled equipment Revise NFPA−54 section 10.8.3 to add the following re- shall not approve the installation unless, upon inspec- quirements: tion, the inspector observes carbon monoxide detec- For all side wall, horizontally vented, gas−fueled equipment...

Lennox MERIT ML193DF Installation Instructions Manual

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