LENNOX {' 2002 Lennox Industries Inc. Dallas, Texas, USA GAS UNITS KITS AND ACCESSORIES 504,605M 02/2002 HEAT EXCHANGER REPLACEMENT KIT INSTALLATION INSTRUCTIONS FOR REPLACEMENT HEAT EXCHANGER (32K47, 32K48, 32K49 & 32K79) USED WITH GHR26 & GHR32Q/V SERIES GAS FURNACES Package 1 of 1 contains the following: 1 - Heat exchanger assembly 1 - Burner box gasket 16 - #8-18 X 314" screws 1-2" plug 1 - Insulation shield 1 - Flanged insulation shield Check equipment for shipping damage. If you find any damage, immediately contact the last carrier. These instructions are intended as a general guide and do not supersede local codes in any way. See table 1 for unit model numbers and corresponding replacement kit catalog numbers. TABLE 1 UNIT MODEL NUMBER REPLACEMENT KIT CATALOG NUMBER GHR26_50 GHR32Q_50 32K47 GHR26W5 GHR32Q/V-75 32K48 GHR26-100 GHR32Q/V-100 32K49 GHR26-120, GHR32Q- 120 32K79 ELECTROSTATIC DISCHARGE (ESD) Precautions and Procedures CAUTION,WARNING Follow the procedure below and refer to figure 1 when disassembling furnace. Use papers or protective covering in front of furnace while removing heat exchanger assembly. Pay attention to wire routing and plumbing connections. Tools needed are: slotted screwdriver, 1/4 inch nut driver with long extension, 5/16 inch nut driver with long extension, and duckbill pliers. 1 - Turn off electrical and gas power supplies to furnace. 2 - Remove upper and lower furnace access panels. 3 - Remove 3/8 inch rubber cap from condensate drain plug and drain. Replace cap after draining. 4- Disconnect and remove intake pipe from air intake fitting. 5 - Mark all gas valve wires and disconnect them from valve. 6- Remove gas supply line connected to gas valve. Disconnect gas valve sensing hose from side of burner box. Remove six (or four) securing screws which hold the burner box cover in place and remove the cover. Remove gas valve/manifold assembly. 7 - Remove sensor wire from ignition control. Disconnect wiring from the ignitor. Disconnect wires from flame roll-out switch. 8 - Remove four screws which secure the burner box to the vestibule panel. Remove burner box. Remove and discard existing burner box gasket. Replacement gasket is provided, 9 - Remove wires from patch plates. NOTE - Take the opportunity to check the burners, ff necessary, clean burners using the procedure outlined in the unit installation instructions. 10 - Loosen three clamps which hold the flexible exhaust tee in place and remove the exhaust tee. 11 - Disconnect drain line attached to condensate trap. Remove screws that secure both condensate collars to either side of the furnace and remove collars. It may be necessary to cut the pipe to allow for removal of the condensate trap. Remove drain tubes from cold end header collector box. Page 1
PARTS IDENTIFICATION (GHR26 Unit in Downflow Application Shown) SECONDARY AUTO-RESET LIMIT (Located on Backside of Blower Wrapper) SUPPLY AiR BACK FILTER CLIP TOP CAP IGNITION CONTROL CONTROL VOLTAGE CIRCUIT BREAKER _ CONTROL "_'-_ '_ BOX CONTROL TRANSFORMER _ CABINET o!! COMBUSTION AIR INDUCER DOOR INTERLOCK SWITCH / t COLD END HEADER (COLLECTOR) BOX X COMBUSTION AiR INDUCER MOUNTING *ACKET FRESH AiR _-I INTAKE EXHAUST TEE _ INTAKE AtR_ --_ GASKET FITTING WITH BARBED PATCH FITTING PLATE i _/- -" " BUR_E_BURNERToP BOX BURNER BOX _ COVER / _ / I / l PRIMARY LIMIT AUTO-RESET (ALTERNATE BURNER BOX GASKET STYLES) COMBUSTION PROVING () SWITCH HOT ENDHEADER (COLLECTOR) CONDENSER COIL DuralokPtusTM HEAT EXCHANGER ASSEMBLY AIR FLUE COLLAR CONDENSATE COLLAR BOX ASSEMBLY _ FLAME ROLL-OUT SWITCH ORIFICE (MANUAL RESET) GLASS FLAME SENSOR IGNITOR GAS VALVE AND MANIFOLD CONDENSATE TRAP FIGURE 1 Page 2
12-Disconnectcondensatedraintubingfrom exhaust pipe.removescrewsthatsecurebothfluecollarsinto place.removefluecollars.it maybenecessary tocut the exitingexhaustpipeto allowfor removalof the fittings. 13- Disconnect wiring harness plug from the combustion air inducer. Remove combustion air inducer from bracket by removing four securing screws. Remove ground wire from bundle. 14 - Remove combustion air inducer bracket by removing two screws from collector box and two screws from vestibule panel. 15 - Disconnect combustion air pressure and condensate sensing hoses from cold end header collector box. Remove the pressure hose from two blank stems on cold end header collector box (early models only). 16-Mark and remove wires from pressure switch. Remove pressure switch/bracket assembly. Keep hoses attached to pressure switch. Remove pressure switch installation screws from both sides of the furnace. 17 - Disconnect harness connector plugs at the blower deck. Remove both plugs from the heat exchanger side of the blower deck. NOTE - The 9-pin harness connectors which join at the blower deck were replaced by a one-piece harness routed through a snap bushing in the blower deck in units produced after November 2001. 18 - Remove the primary limit from vestibule panel. 19 - Remove two screws from the front cabinet flange at the blower deck. Remove front screws from cabinet at blower deck on left and right sides. Cabinet sides must be slightly spread apart to clear heat exchanger passage. NOTE - To protect insulation in horizontal applications, slide the provided sheet metalshields between the coil section of the heat exchanger and the cabinet when removing and replacing heat exchanger. Remove indoor blower for horizontal installations. Remove sheet metal when complete. 20- Remove screws along vestibule sides and bottom which secure vestibule panel and heat exchanger assembly to cabinet. Remove heat exchanger, 21- Install replacement heat exchanger into cabinet (blower deck end first) making sure that the clamshells of the heat exchanger assembly are resting on the supports at the rear of the cabinet. This can be viewed by removing the indoor blower and examining through the blower opening. 22 - Secure the heat exchanger to the cabinet along the vestibule sides and bottom using the provided #8-32 X 3/4" screws. 23 - Reinstall primary limit on vestibule panel. 24-Reconnect 9-pin plug at the blower deck to the matching 9-pin plug from below the blower deck. Reconnect 2-pin or 3-pin plug (depending on unit) to matching plug from below the blower deck. 25-Reinstall pressure switch/bracket assembly and replace pressure switch screws on both sides of furnace from installed pressure switch, Reconnect wires to pressure switch. IMPORTANT MPL TRIDELTA / HONEYWELL PPS (Metal/Plastic Construction) POSITIVE (Marked With "-" POSITIVE (Marked With "+") TRIDELTA / HONEYWELL (All Metal Construction) TRIDELTA / HONEYWELL IS2 (NO Markings) Hose Connection Side OnIy) POSITIVE (NO Markings EiectricaI Terminal and Hose Connection Side) side marked "-") POSITIVE (btack side marked "+") FIGURE 2 Page 3
HORIZONTAL LEFT-HAND AIR DISCHARGE Connecthose (redsquare) to POSITIVEside on pressure switchandopen tap on FRONT of collectorbox. Pressure Switch DOWNFLOW AIR DISCHARGE Connect hose (black round To side on pressure switch and open tap on FRONT of collector box. Pressure Switch AIR FLOW Connect hose (red square) to POSITIVE side.. on pressure switch and open tap on FRONT of collector box. Connect hose (black round) To "'side on pressure switch and open tap on SIDE of collector box. HORIZONTAL RIGHT-HAND DISCHARGE Connectthe red squarehose to the POSITIVEside on pressure switchand the open tap on the FRONT of the collectorbox. f CONNECTIONS (Downfiow Air Discharge Application Shown) (Black round tubing beginning with =6 models) o no o[1 o _ BLANK STEMS EARLY MODEL _ UNITS ONLY _ Pressure Collector Box Switch _ must be on top side of unit. O O AIR FLOW i o o /_ POSI'TIVE CONNECTIONS (Red square tubing beginning with -6 models) FIGURE 3 Connect the black round hose to the side on the pressure switch and SIDE of the collector box. 26- Connect combustion air pressure and condensate sensing hoses from pressure switch to cold end header collector box, See figure 3 to confirm hose location.,&warning 27 - Reinstall the combustion air inducer bracket. 28 - Reinstall the combustion air inducer on the bracket. Reconnect the harness connector plug to the wiring harness. 29 - Replace flue collars with securing screws to either side of the furnace. Reconnect exhaust piping and exhaust drain tubing. 30 - Replace condensate collars with secunng screws to either side of the furnace. Reconnect drain line to condensate trap. Reconnect drain tubing from cold end header collector box. Reconnect condensate drain tubing from exhaust pipe. 31- Replace flexible exhaust tee to combustion air inducer and exhaust pipes and secure with three clamps, 32-Align replacement burner box gasket to securing holes closest to the end of the furnace, Use a small piece of tape to secure gasket to vest panel. Gasket must provide a continuous seal between the burner box and the vestibule panel, 33 - Replace four screws to secure reassembled burner box assembly to vestibule panel. Make sure burners line up in center of burner ports. 34 - Reconnect flame roll-out switch wires. 35-Reconnect sensor wire to ignition control and reconnect wiring harness plug from ignitor. Page 4
36-Reinstall gas valve manifoldassembly.replace burnerboxcover.reconnectgassupplylineto gas valve.attachgas valvepressuresensinghoseto burnerbox. 37- Reconnect gasvalvewirestogasvalve. 38- Reinstallintakevent pipeon rubberconnectoron intakefittingusinghoseclamp. 39- Replacebothupperandloweraccesspanels. 40- Refertotheunitinstallationinstructions toverifygas and electricalconnectionswhen re-establishing supply.use a leak detectingsolutionor other preferredmeanstocheckforgasleaks. A, CAUTION 41 - Light the burners and allow the unit to operate for 5 minutes to ensure that the heat exchanger is clean, dry, and operating safely. Follow the lighting instructions on the unit sticker or in the unit installation instruction manual. Page 5