Lennox International Inc. Lennox Merit Series Gas Furnace Upflow/Horizontal Air Discharge manual

Page 1 08/13 *2P0813* 507121-01 *P507121-01* E 2013 Lennox Industries Inc. Dallas, Texas, USA AIR FLOW UPFLOW AIR FLOW AIR FLOW HORIZONTAL RIGHT HORIZONTAL LEFT INSTALLATION INSTRUCTIONS ML193UH MERIT ® SERIES GAS FURNACE UPFLOW / HORIZONTAL AIR DISCHARGE 507121-01 08/2013 Supersedes 06/2013 THIS MANUAL MUST BE LEFT WITH THE HOMEOWNER FOR FUTURE R[...]

Page 2 ML193UH Unit Dimensions - inches (mm) 6−9/16 (167) Left 9 (229) Right 23 (584) (19) 3/4 (19) 1 Bottom Return Air Opening GAS PIPING INLET (Either Side) Side Return Air Opening (Either Side) 1 Bottom Return Air Opening EXHAUST AIR OUTLET ELECTRICAL INLET (Either Side) SUPPL Y AIR OPENING FRONT VIEW SIDE VIEW TOP VIEW A B 9/16 (14) C 3/4 27?[...]

P age 3 ML193UH Gas Furnace The ML193UH Category IV gas furnace is shipped ready for installation in the upflow or horizontal position. The fur nace is shipped with the bottom panel in place. The bottom panel must be removed if the unit is to be installed in hori zontal or upflow applications with bottom return air. The ML193UH can be install[...]

Page 4 Gas Code is available from the following address: American National Standards Institute, Inc. 11 West 42nd Street New York, NY 10036 In Canada, installation must conform with current National Standard of Canada CSA‐B149 Natural Gas and Propane Installation Codes, local plumbing or waste water codes and other applicable local codes. In orde[...]

P age 5 D Air filters must be replaced upon construction comple tion. D The input rate and temperature rise must be set per the furnace rating plate. D One hundred percent (100%) outdoor air must be pro vided for combustion air requirements during construc tion. Temporary ducting may supply outdoor air to the furnace. Do not connect duct d[...]

Page 6 will build to the point that a downdraft can occur in the fur nace vent pipe or chimney. As a result, combustion gases enter the living space creating a potentially dangerous situ ation. In the absence of local codes concerning air for combus- tion and ventilation, use the guidelines and procedures in this section to install ML193UH fu[...]

P age 7 Air from Outside If air from outside is brought in for combustion and ventila tion, the confined space shall be provi ded with two perma nent openings. One opening shall be within 12” (305mm) of th e top of the enclosure and one within 12” (305mm) of the bottom. These openings must communicate directly or by ducts with the outdoor[...]

Page 8 FIGURE 8 EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE (All Air Through Ventilated Attic) NOTE -The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645mm 2 p er 1.17kW) per hour of the total input rating of all equipment in the enclosure. OUTLET AIR VENTILATION LOUVERS (Each end of at[...]

P age 9 FIGURE 11 SETTING EQUIPMENT UPFLOW APPLICA TION HORIZONTAL APPLICATION FRONT VIEW SIDE VIEW FRONT VIEW END VIEW UNIT FRONT AIR FLOW UNIT FRONT 1/2” max. 1/2” max. AIR FLOW AIR FLOW SIDE VIEW UNIT FRONT Unit must be level side-to-side. Unit may be positioned from level to 1/2” toward the front to aid in draining.[...]

Page 10 WARNING Improper installation of the furnace can result in per sonal injury or death. Combustion and flue products mus t never be allowed to enter the return air system or air in th e living space. Use sheet metal screws and joint tape to seal return air system to furnace. In platform installations with f urnace return, the fur nace s[...]

P age 11 FIGURE 14 Optional Return Air Base (Upflow Applications Only) NOTE- Optional side return air filter kits are not for use with return air base. 1 Both the unit return air opening and the base return air opening must be covered by a single plenum or IAQ cabinet. Minimum unit side return air opening dimensions for units requiring 1800 cfm of [...]

Page 12 The ML193UH furnace can be installed in horizontal ap plications with either right- or left-hand air discharge. Refer to fig ure 17 for clearances in horizontal applications. Horizontal Application Installation Clearances Left End Right End Right-Hand Discharge Left-Hand Discharge Top Bottom (Floor)** Bottom (Floor)** Left End Right End [...]

P age 13 FIGURE 19 *GAS CONNECTION RAISED PLA TFORM SERVICE PLA TFORM INT AKE PIPE EXHAUST PIPE Return Air -- Horizontal Applications Return air may be brought in only through the end of a fur nace installed in the horizontal position. The furnace is equipped with a removable bottom panel to facilitate instal lation. See figure 15. Filters Th[...]

Page 14 CAUTION Solvent cements for plastic pipe are flammable liq uids and should be kept away from all sources of ignition. Do not use excessive amounts of solvent ce me nt when making joints. Good ventilation should be maintained to reduce fire hazard and to minimize breathing of solvent vapors. Avoid contact of ce ment with skin and eyes.[...]

P age 15 TABLE 3 OUTDOOR TERMINATION USAGE* Input Size Vent Pipe Dia. in. STANDARD CONCENTRIC Flush Mount Kit Wall Kit Wall Ring Kit Field Fabricated 1-1/2 inch 2 inch 3 inch 2 inch 3 inch 2 inch 51W11 (US) 51W12 (CA) 22G44 (US) 4 30G28 (CA) 44J40 (US) 4 81J20 (CA) 15F74 71M80 (US) 4 44W92 (CA) 69M29 (US) 4 44W92 (CA) 60L46 (US) 4 44W93 (CA) 045[...]

Page 16 NOTE - Assembly should be completed within 20 sec onds after last application of cement. Hammer blows should not be used when inserting pipe. 8 - After assembly, wipe excess cement from pipe at end of fitting socket. A properly made joint will show a bead around its entire perimeter. Any gaps may indicate an improper assembly due to insu[...]

P age 17 Vent Piping Guidelines The ML193UH 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 out doors. In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged o[...]

Page 18 TABLE 5 Maximum Allowable Intake or Exhaust Vent Length in Feet NOTE - 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. NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in[...]

P age 19 FIGURE 24 TYPICAL EXHAUST PIPE CONNECTIONS IN UPFLOW DIRECT OR NON-DIRECT VENT APPLICATIONS TRANSITION 2” 2” 2” 3” 2” 2” or Pipe size determined in table 5 DO NOT transition from smaller to larger pipe in horizontal runs of exhaust pipe. EXHAUST *2” * When transitioning up in pipe size, use the shortest length of 2” PVC pip[...]

Page 20 FIGURE 26 TYPICAL AIR INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT VENT APPLICATIONS *2” TRANSITION 2” 3” Pipe size determined in table 5 2” 2” 2” 2” or AIR INTAKE * When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible. NOTE − Intake and exhaust pipe must be the same diameter . or FIGURE 27 TYPIC[...]

P age 21 Intake Piping The ML193UH furnace may be installed in either direct vent or non-direct vent applications. In non-direct vent applications, when intake air will be drawn into the furnace from the surrounding space, the indoor air quality must be considered and guidelines listed in Combustion, Dilution and Ventilation Air section must be fol[...]

Page 22 CAUTION If this unit is being installed in an application with combustion air coming in from a space serviced by an exhaust fan, power exhaust fan, or other device which may create a negative pressure in the space, take care when sizing the inlet air opening. The in let air opening must be sized to accommodate the maximum volume of exhau[...]

P age 23 TABLE 7 Maximum Allowable Exhaust Vent Pipe Length (in ft.) Without Insulation In Unconditioned Space For Winter Design Temperatures Single - Stage High Efficiency Furnace Winter Design Temperatures 1 °F (°C) Vent Pipe Diameter Unit Input Size 045 070 090 110 135 32 to 21 (0 to -6) PVC PVC PVC PVC PVC 2 in. 26 44 44 24 N/A 2-1/2 in. 18 3[...]

Page 24 FIGURE 33 ** VENT TERMINATION CLEARANCES FOR NON-DIRECT VENT INSTALLATIONS IN THE USA AND CANADA K D E L B C F G A B J A M I H INSIDE CORNER DETAIL VENT TERMINAL AIR SUPPLY INLET AREA WHERE TERMINAL IS NOT PERMITTED Fixed Closed Operable B Fixed Closed Operable B B A = B = C = D = E = F = G = H = I = J = K = L = M = US Installations 1 Canad[...]

P age 25 FIGURE 34 VENT TERMINATION CLEARANCES FOR DIRECT VENT INSTALLATIONS IN THE USA AND CANADA K D E L B C F G A B J A M I H INSIDE CORNER DETAIL VENT TERMINAL AIR SUPPLY INLET AREA WHERE TERMINAL IS NOT PERMITTED Fixed Closed Operable B Fixed Closed Operable B B A = B = C = D = E = F = G = H = I = J = K = L = M = US Installations 1 Canadian In[...]

Page 26 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. NOTE - Flue gas may be slightly acidic and may adversely affect some building materials. If any vent termination is used and the flue gasses may[...]

P age 27 7 - If intake and exhaust piping must be run up a si de wall to position above snow accumulation or other ob structions, piping must be supported. At least one bracket must be used within 6” from the top of the el bow and then every 24” (610mm) as shown in figure 42, to prevent any movement in any direction. When exhaust and inta[...]

Page 28 FIGURE 42 * 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). NOTE − One wall support must be within 6” (152 mm) from top of each pipe (intake and exhaust) to prevent movement in any direction. NOTE − FIELD−PROVIDED REDUCER MA Y BE REQUIRED TO ADAP[...]

P age 29 ML193UH DIRECT VENT APPLICATION USING EXISTING CHIMNEY NOTE - Do not discharge exhaust gases directly into any chimney or vent stack. If ver tical 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 terminate as illus trated. In any exteri[...]

Page 30 NOTE - If necessary the condensate trap may be installed up to 5’ away from the furnace. Use PVC pipe to connect trap to furnace condensate outlet. Piping from furnace must slope down a minimum of 1/4” per ft. toward trap. 1 - Determine which side condensate piping will exit the unit, location of trap, field-provided fittings and length[...]

P age 31 FIGURE 48 (Unit shown in upflow position with remote trap) *5’ max. T o Drai n PV C Pipe Only Field Provided V ent Min. 1” Above Condensate Drain Connection 1” Min. 2” Max. CONDENSATE TRAP LOCA TIONS *Piping from furnace must slope down a minimum of 1/4” per ft. toward trap. FIGURE 49 ML193UH With Evaporator Coil Using A Separ[...]

Page 32 FIGURE 51 ML193UH with Evaporator Coil Using a Separate Drain (Unit shown in horizontal left-hand discharge position) . 5’ max. PVC Pipe Only 4”min 5”max Evaporator Coil Drain Pan Condensate Drain Connection Field Provided Vent (4” min. to 5” max. above condensate connection) *Piping from furnace and evaporator coil must slope dow[...]

P age 33 FIGURE 54 Drain T rap Assembly (Furnished) V ent Drain T rap Clean Out 5 Feet Maximum Coupling 3/4 inch slip X slip (Not Furnished) 90 ° Elbow 3/4 inch PVC (Not Furnished) 3/4 inch PVC Pipe (Not Furnished) 1/2 inch PVC Pipe (Not Furnished) Condensate Drain Connection In Unit Drain Assembly for 1/2 inch Drain Pipe 90 ° Elbow 3/4 inch PVC [...]

Page 34 Gas Piping CAUTION 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) t[...]

P age 35 GROUND JOINT UNION AUTOMATIC GAS VALVE (with manual shut-off valve) FIELD PROVIDED AND INSTALLED Left Side Piping (Standard) DRIP LEG MANUAL MAIN SHUT-OFF VALVE Right Side Piping (Alternate) NOTE - BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET Bellows Grommet Plug Plug GROUND JOINT UNION DRIP LEG MANUAL MAIN SHUT-OFF VALVE Gas Valve [...]

Page 36 TABLE 9 GAS PIPE CAPACITY - FT 3 /HR (kL/HR) Nominal Iron Pipe Size -Inches(mm) Internal Diameter -Inches(mm) Length of Pipe-Feet(m) 10 (3.048) 20 (6.096) 30 (9.144) 40 (12.192) 50 (15.240) 60 (18.288) 70 (21.336) 80 (24.384) 90 (27.432) 100 (30.480) 1/2 (12.7) .622 (17.799) 175 (4.96) 120 (3.40) 97 (2.75) 82 (2.32) 73 (2.07) 66 (1.87) 61 ([...]

P age 37 Electrical ELECTROSTATIC DISCHARGE (ESD) Precautions and Procedures CAUTION Electrostatic discharge can affect elec tronic components. Take precautions to neutralize electrostatic charge by touching your hand and tools to metal prior to handling the control. INTERIOR MAKE-UP BOX INSTALLATION FIGURE 59 MAKE-UP BOX Right Side remove and r[...]

Page 38 Generator Use - Voltage Requirements The following requirements must be kept in mind when specifying a generator for use with this equipment: D The furnace requires 120 volts + 10% (Range: 108 volts to 132 volts) D T he furnace operates at 60 Hz + 5% (Range: 57 Hz to 63 Hz) D The furnace integrated control requires both polarity an d proper[...]

P age 39 Integrated Control FIGURE 1 INTEGRATED CONTROL (Automatic Hot Surface Ignition System) BLOWER OFF DELAY JUMPER PUSH BUTTON LED TWIN TERMINAL DESIGNA TIONS HUM LINE XFMR EAC COOL HEAT PARK CONT NEUTRALS Humidifier (120VAC) Input (120VAC) Transformer (120VAC) Indoor Air Qality Accessory Air Cleaner (120VAC) Blower - Cooling Speed (120VAC) Bl[...]

Page 40 Unit Start-Up FOR YOUR SAFETY READ BEFORE OPERATING WARNING Do not use this furnace if any part has been under water. A flood-damaged furnace is extremely dan gerous. Attempts to use the furnace can result in fire or explosion. Immediately call a qualified service technician to inspect the furnace and to replace all gas controls, cont[...]

P age 41 4 - Move gas valve switch to OFF. 5 - Replace the upper access panel. Failure To Operate If the unit fails to operate, check the following: 1 - Is the thermostat calling for heat? 2 - Are access panels securely in place? 3 - Is the main disconnect switch closed? 4 - Is there a blown fuse or tripped breaker? 5 - Is the filter dirty or plugg[...]

Page 42 Proper Combustion Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking com bustion. Take combustion sample beyond the flue outlet and compare to the tables below. TABLE 12 ML193 Unit CO 2 % For Nat CO 2 % For L.P. -045 7.2 - 7.9 8.6 - 9.3 -070 -090 -110 -135 The maximum carbon monoxid[...]

P age 43 Testing for Proper Venting and Sufficient Combustion Air for Non-Direct Vent Applications 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 monox ide poisoning or death. The following steps shall be fo[...]

Page 44 Other Unit Adjustments Primary Limit . The primary limit is located on the heating compartment vestibule panel. This limit is factory set and requires no ad justment. Flame Rollout Switches (Two) These manually reset switches are located on the front of the burner box. Pressure Switch The pressure switch is located in the heating compart[...]

P age 45 Twinning the ML193UH The control board in this furnace is equipped with a provi sion to ”t w in” (interconnect) two(2) adjacent furnaces with a common plenum such that they operate as one (1) large unit. When twinned, the circulating blower speeds are synchro nized between the furnaces. If either furnace has a need to run the blo[...]

Page 46 Service WARNING ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD. Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage. Improper servicing could result in dangerous opera tion, serious injury, death, or property damage. Before servicing, disconnect all electrical power to furn[...]

P age 47 Repair Parts List The following repair parts are available through Lennox dealers. When ordering parts, include the complete furnace model num be r listed on the CSA nameplate -- Example: ML193UH045XP36B-01. All service must be performed by a licensed professional installer (or equivalent), service agency, or gas supplier. Cabinet Parts Up[...]

Page 48 Start-Up & Performance Check List Gas Supply Pressure SUPPL Y AIR Line V oltage GAS SUPPLY Natural Gas LP Propane Gas Piping Connections Tight Leak Tested Supply Line Pressure “W.C.________ 1 INTAKE / EXHAUST PIPE All Joints Primed and Glued Terminations Installed Properly Pipes Sup ported Condensate Trap Primed / Line Sloped Heat [...]

P age 49 Contractor's: Name_________________________Telephone_____________Checklist Completed____________________ Job Address_____-________________________________Technician's Name___________________________________ 1 HEATING MODE GAS MANIFOLD PRESSURE “W.C._____ COMBUSTION SAMPLE CO 2 % ______ CO PPM_______ 2 INDOOR BLOWER AMPS______ 3[...]

Page 50 Requirements for Commonwealth of Massachusetts Modifications to NFPA-54, Chapter 10 Revise NFPA-54 section 10.8.3 to add the following re  quirements: Fo r all side wall, horizontally vented, gas-fueled equipment installed in every dwelling, building or structure used in whole or in part for residential purposes, including those owned or[...]

P age 51 FOR THE PROVINCE OF ONTARIO, HORIZONTAL SIDEWALL VENT APPLICATIONS ONLY For exterior horizontal venting applications, the 2” X 1.5” reducer for 2” venting at the point where the exhaust pipe exits th e st ruc tur e i s no t r equired in direct or nondirect vent applications in the Province of Ontario. In these applica tions, th[...]