4AgendaProduct Line Overview New Features Installation Adjustment Servicing
5Overview 95.5 AFUE 4-way multipoise 100 & 120 size140 size limited to Upflow & HorizontalAluminized steel primary and stainless steel secondary heat exchangersDirect Vent or Non-Direct Venting
6New Features Lower height, now 35” Standard widths 21” for 100 and 120 sizes24 ½” for 140 sizesThrough-the-top ventingMultiple venting optionsInternal Condensate system
7New Features Slide out blowers Ease of access for control board Two outer doorsEasy door attachmentsNo sharp edgesQuarter-turn knobs and latches
8New Features Redesigned primary heat exchanger More compactNo eyeletsUpdated tube-and-fin secondaryBetter efficiencyEliminated U-bendEasier to service with slide-out railsUp to 97 AFUE. Eliminates “gurgle” in downflow Eliminates hiding places for process oils
9New Technologies True installation flexibility Venting flexibility Vent pipes can exit cabinet in three different directionsLow-profile horizontal drain trap positionEasy to re-position the drain trapFewer tubes to connectDrain trap and tubes removed from the blower compartment
10CasingThis is a typical dimensional drawing. Note the intake and vent pipe knock-outs on the top plate of the casing. Not all families will have a 40,000 btuh model and not all 60,000 and 80,000 models will be in a 17 ½” wide casing. Refer to the product data for specific casing details.
11CasingThis is a typical dimensional drawing. Note the intake and vent pipe knock-outs on the top plate of the casing. Refer to the product data for specific casing details.
12CasingThis is a typical dimensional drawing. Note the intake and vent pipe knock-outs on the top plate of the casing. Refer to the product data for specific casing details.
13Casing 35” Combustion Air Opening Gas Entry Horizontal Drain Trap OpeningVent or Combustion Air OpeningCondensate Drain K.O.J Box K.O.Return Air OpeningCombustion Air OpeningGas EntryVent or Combustion Air OpeningHorizontal DrainTrap OpeningCondensate Drain K.O.J Box K.O.Return Air Opening
14Outer Door Assembly Two piece door design ¼ turn door knob attachment Doors are gasketedEliminates door rattling and leakageVestibule is sealedDoor does NOT change with furnace orientationLogo rotates for upflow and downflow positions
15Outer Door Assembly Vestibule functions as the burner compartment Combustion air piped directly to the vestibuleMultiple locations to connect combustion air pipeSealed burner box is not requiredSimplifies set-up
16Upflow Return Air Connections In the upflow position, any combination of return air connections may be used. Each connection at the furnace must have a field supplied filter and filter rack installed at external to furnace unless filters are located in the return grills. There are no provisions for an internal filter rack.
17Downflow Return Air Connections In the downflow position, only connect return air to the factory opening in the casing. Do not use the sides of the casing as a return air connection! Erratic limit switch operation may result. A field supplied filter and filter rack must be installed at the furnace or in the return grills of the duct system. There are no provisions for
18Horizontal Return Air Connections In the horizontal position, only connect return air to the factory opening in the casing, or in the side of the casing facing down. Do not use the top side of the casing as a return air connection! Erratic limit switch operation may result. A field supplied filter and filter rack must be installed at each return connection or in the return grills of the duct system. an internal filter rack. Horizontal right installations are similar.
23Terminations Direct Vent Ventilated Combustion Air Single Pipe Concentric VentField-fabricated 2-pipeVentilated Combustion AirVent to outdoorsCombustion air from attic or crawlspaceSingle PipeUses indoor air for combustion
24Ventilated Combustion Air Option The combustion air pipe for the Ventilated Combustion Air Option cannot be terminated in attics or crawlspaces that use ventilation fans designed to operate during the heating season. If ventilation fans are present in these areas, the combustion air pipe must terminate outdoors as a Direct Vent / 2-Pipe system.
25Indoor Air For Combustion Option Use a (minimum) 12-inch piece of PVCMaximum of 5 feetTight radius elbowFace away for better sound controlSecure pipe to adapterPilot drill 1/8” holeInstall sheet metal screwSeal with silicone12” (min)
26Alternate Indoor Air For Combustion Connection 12” (min)12” (min)
27Supply Air Flanges Flanges shipped flat If flanges are not bent, nuisance limit trips could occurBend flanges UP for upflow or horizontal coil installationsRemove or bend flanges DOWN for downflow coil installationsNo downflow for 140,000 inputSupply opening match current coil opening sizes
29Return Air Connections UpflowEither SideBottomAny combination of Sides and BottomDownflow (100,000 BTUH & 120,000 BTUH)Bottom only (“bottom” as referenced to furnace in upflow position)HorizontalSide (side facing down only)Airflow above 1800 cfm may require both side/bottom return or bottom only returnRemove closure panel for bottom return airThe furnace sides are the return air openings at the blower compartment as you view the furnace. The bottom of the furnace is where the closure pan is installed when viewed in the upflow position. The return air can never be connected to the back of the furnace. Never connect any ductwork or accessories to the heat exchanger compartment of the furnace.
30Return Air Connections In the horizontal position, only the side facing down can be used as a return air connection.
31Gas Piping Gas pipe can enter from either side Remove K/O on either side gas entryInstall grommet in casingFlex lines must connect outside of the casing per the NFGCSediment trap required per NFGC
32Optional Right Side Gas Entry No special fittings for left side entryValve inlet is ½” NPTInstall Street Ell, 2” nipple and 90º elbow togetherInstall Street Ell into gas valveRemove K/O from casingInstall gas pipe grommet in casing(Required For Direct Vent)Install gas line into elbowTighten gas lineUse backup wrench on gas valve!
33J-Box Installation J-box bracket and cover shipped in loose parts bag J-box can be relocated to opposite sideOther electrical knock-outs are available
34J-Box Installation Remove 7/8” knockout in casing Install J-box bracketAttach ground wire to green ground screwInstall cover after all other connections are madeOther electrical knock-outs are available
35Typical Disconnect At Furnace Power Cord Installation in Furnace J-Box (Where permitted)NOTE: Power cords must be able to handle the electrical requirements listed in Table 6. Refer to power cord manufacturer’s listings.Remove 7/8” K.O. in casing.Attach J box bracket to casing.3. Route listed power cord through 7/8--in. (22 mm) diameter hole in casing.Attach power cord to J--Box bracket with a strain relief bushing or aconnector approved for the type of cord used.5. Attach field ground wire to green ground screw on J-Box bracket.6. Connect line voltage leads as shown in wiring diagram7. Install cover to J--Box. Do not pinch wires between cover and bracket.If a field-supplied disconnect is provided at the furnace casing, the J box is not required provided: The disconnect is grounded to the green ground lead and the furnace casing.
36UpflowThis is how the inducer assembly looks in the upflow position. To install the furnace in the downflow or horizontal orientation, it will be necessary to relocate the condensate trap, the condensate trap relief tube and pressure switch tube.
37Downflow - Trap Unconverted PSC Inducer Models The installation instructions will show you how the furnace looks in the unconverted and converted orientations. Each step is numbered in the drawings to aid you in the conversion. The first drawing will be in the installed unconverted orientation and the second drawing will show you how it should look in the properly converted orientation. The 140 size furnace cannot be installed in the downflow orientation.
38Downflow - Trap Converted PSC Inducer Models Route tube throughSwitch Tube to PortOn Collector BoxAfter you remove the components in the unconverted drawing, use the numbered steps in the converted drawing to re-install the components for the required orientation. The 140 size furnace cannot be installed in the downflow orientation.To 15 ib-in
39Horizontal Left - Trap Unconverted PSC Inducer Models Horizontal left is when you view the furnace from the front and the air discharges to your left
40Horizontal Left - Trap Converted PSC Inducer Models Route Pressure SwitchRemember to follow all the steps and install the plug you removed in the remaining open port of the collector box.
41Horizontal Right - Trap Unconverted PSC Inducer Models Horizontal right is when you view the furnace from the front and the air discharges to your right
42Horizontal Right - Trap Converted PSC Inducer Models Remember to follow all the steps and install the plug you removed in the remaining open port of the collector box.
43Horizontal Trap Grommet An accessory rubber grommet is available to seal the condensate trap to the casing in horizontal installation. This grommet is only required when direct venting (sealed combustion) is requiredRequired accessory for Direct Vent applications (only)Maintains a sealed vestibule
44Repositioning Vent Elbow The vent elbow provides venting flexibility by rotating 360 degrees to allow the vent to exit the casing through the sides or through the blower compartment when the accessory internal vent kit is used. Do not run the vent and combustion air pipes through the blower compartment without using the accessory internal vent kit. The internal vent kit seals the blower compartment from the vestibule of the furnace. If the kit is not used, products of combustion may be drawing into the blower compartment and circulated through the airstream into the living space.Loosen the Vent Elbow Clamp.Remove the Vent Elbow.Re-install in the desired position.Torque clamp 15 lb-in.
45Condensate Trap and Drain Elbow Clear trapShown for clarityProduction TrapWhite, Opaque front/Clear backThe trap is clear in the back to allow service technicians to verify the trap is clean after flushing it out. Cleaning the trap is recommended as part of a regular maintenance program. The gasket between the trap and collector box should be replace if the trap is removed for service. The rubber drain elbow and clamp is shipped in the loose parts bag and is used to complete the condensate drain to the furnace casing.
46Condensate Trap Mounting Screw Hole Expanded View Outlet Relief Port InletsFront View Back ViewMounting Screw HoleThere are 2 sets of drain openings in the rear of the trap. One is for the inducer assembly and the other is for the collector box. The trap cannot be disassembled and is only shown as a reference. The relief port acts as a “vent” and is connected to the opposite corner of the collector box.
47Right Side Drain Production trap will be opaque front/clear back Connect field supplied CPVC fittings to drain tubeClamp may be located inside casingConnect condensate drain to code approved drain or condensate pump approved for furnace condensate
48Right Side DrainThis is the image shown in the installation instructions. Connect the field supplied CPVC pipe to the outlet of the drain elbow. If PVC drain is used, a CPVC to PVC adapter is shipped in the loose parts bag. Remember to clamp the drain pipe to the drain elbow to prevent condensate leaks.
49Left Side Drain Cut the tube as shown Install formed end of grommet in the left side of the casingConnect the elbow to the short end of Z pipeSlide clamps on elbow and pipeRoute Z pipe behind inducerThe inducer can be removed if necessary to install the Z pipe
50Left Side DrainThis is how the left side drain looks without any components in front or behind it. Note is this example, the ½” CPVC to ¾” adapter is attached to the formed end
52Vent Sizing New tables based on Maximum Equivalent length Starts with a maximum lengthDeduct for type of fitting usedNo restriction on number of elbowsDiameters up to 4 inches on larger sizesExpanded exposed vent pipe tablesWinter design down to -40 deg. F (C)½ inch insulation addedClosed cell Armaflex type
53Maximum Equivalent Length Table The vent and intake air pipe maximum lengths decrease as the installation altitude increases. The vent tables go up to 10,000 ft. (3048m)
54Deductions Table and Example Different types of elbow have different equivalent lengths. These lengths are subtracted from the maximum allowable length of vent or combustion air pipe. The two terminations shown have 0 losses and are figured into the maximum vent lengths.
55Vent Table Notes1. Use only the vent pipe sizes shown for each furnace. It is NOT necessary to choose the smallest diameter pipe possible for venting. 2. NA – Not allowed. Pressure switch will not close, or flame disturbance may result. 3. Size both the combustion air and vent pipe independently, then use the larger size for both pipes. 4. Assume the two 45_ elbows equal one 90_ elbow. Wide radius elbows are desirable and may be required in some cases. 5. Elbow and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count. 6. The minimum pipe length is 5 ft. (2 M) linear feet (meters) for all applications. 7. Use 3–in. (76 m) diameter vent termination kit for installations requiring 4–in. (102 mm) diameter pipe.
56Sizing The Vent PipeFollow the example above to size the vent and combustion air pipe. This example is for a complete rigid PVC vent system.
57Sizing The Vent Pipe DRAFT COPY - ICP CONFIDENTIAL Follow the example above to size the vent and combustion air pipe. This example is for a polypropylene vent system that uses a flexible section of vent material.DRAFT COPY - ICP CONFIDENTIAL
58Vent Pipe Support Helps support vent pipe Notches in coupling slide over buttresses on adapterAdds to unit serviceabilityProvides an optional disconnect point
59Combustion Air Adapter Attach to K.O. on casingAny unused top or side K.O. may be usedConnect 2” combustion air pipe to casingGluing is not recommendedPilot drill 1/8” hole and secure with ½” #7 sheet metal screwSeal with silicone
60Comparing the Two Adapters (Both fit 2” PVC pipe) Combustion Air Pipe AdapterVent PipeSupport2 3/8”2”Internal pipe stopNo pipe stop
61Vent Coupling & Adapter Coupling is notchedProvides for proper orientation of couplingNotches slide over buttresses on adapter
62Vent Pipe Coupling & Combustion Air Pipe Adapter Gaskets
63Continuous Vent Pipe Vent pipe Vent coupling w/clamps Inserts through coupling to vent elbowVent coupling w/clampsSlides over adapterVent coupling adapterAttaches to furnace casingPasses through adapterInserts into Vent Elbow360° Vent ElbowConnects to vent pipe
64Flush Mount Vent Pipe Vent pipe Vent coupling w/clamps Inserts ½ way into couplingVent coupling w/clampsSlides over adapterVent coupling adapterAttaches to furnace casingVent pipe from inducerPasses through adapter360° Vent couplingVent pipe connects to couplingIn this arrangement, the vent pipe from the inducer is a separate pipe from the rest of the vent system. The pipes are “split” in the middle of the vent coupling. The vent pipe from the inducer must be cemented or sealed to the vent pipe adapter. The advantage to this arrangement is if the furnace needs major service, the vent can be disconnected without cutting the vent pipe. The pipe from the inducer can then be removed by removing the adapter from the furnace casing.
65Flush Mount Vent Pipe Measure the vent pipe Insert pipe through K.O and adapter w/gasket installedInsert pipe into vent elbowSlide adapter down on furnace casingMark the pipe at the top of the adapterRemove pipe from vent elbowCut pipe squareThis method is used to make a removable connection at the top plate of the furnace.
66Optional Flush Mount Vent Pipe Clean and prime vent pipePipe is inserted in vent elbowClean and prime pipeAdapter with gasket is glued to vent pipeInsert vent pipe into vent elbowApply cement to pipe and adapterSlide adapter over vent pipeIf pipe is not glued to the adapter, the pipe will leak water!
67Optional Flush Mount Vent Pipe Attach vent pipe adapter to furnace casing with screwsInstall vent couplingAlign notches in vent coupling over stand-offs on vent pipe adapterPush down to seat couplingSeat coupling on adapterTorque clamp 15 lb-in.
68Optional Flush Mount Vent Pipe Insert remaining vent pipe into couplingTorque clamp on coupling 15 lb-in.Torque clamp on vent elbow 15 lb-in.
69Vent Through Casing Side Install adapter/gasketInstall coupling-Align notched and fully seat on vent pipe adapterAttach remaining vent pipeTorque all clamps 15 lb-in.
70Combustion Air Pipe (Non-Direct Vent) 12”12”12”Requires a (minimum) 12-inch pipe w/tight radius elbowPipe can be attached to any un-used 2-inch K.O.Orient elbow or pipe away from frontNo combustion air disk requiredCan be screened using ½” metal or plastic screening
72Single- and Two-Stage Inducer Assemblies Three unique sizes for eachPSC ball bearing motorProvides optimum performanceAdjustable vent couplingAdjusts to 4 positionsLoosen the clamp, rotate the coupling, re-tighten the clampIntegral condensate drainageNo external hoses requiredService replacement will be fully assembled
73Key Features Inducer Assembly Drain outlets with gasketsMounting tabsInlet gasketFlue gas inlet
75Integrated Inducer Vent/Drain Flue gases exit through the inner openingEach type of inducer has a set of concentric outlets behind the inducer elbow. The outlet on the outside allows any condensate from the vent pipe to pass back through the inducer housing and out one of the 2 drain openings in the back of the inducer. The inner outlet is for flue gases to exit into the non-metallic vent pipe.The larger opening channels condensate from the vent through the inducer and out the drain openings in the back of the inducer.
76Vent Condensate Drainage Flue gases exit through the inner openingThe larger opening channels condensate from the vent through the inducer and out the drain openings in the back of the inducer.DRAFT COPY - ICP CONFIDENTIAL
77Collector Box-Front View Inducer drain openingsInducer attachment points w/brass inserts (red circles)Condensate trap gasketCondensate trap openings for upflow and horizontal rightCondensate trap openings for downflow and horizontal leftPressure Switch/Relief portOutlet to inducerPressure Switch/Relief portThe inducer assembly attaches to the collector box at 5 points. A brass insert is molded into the collector box to prevent stripped or broken mounting point. There are 2 sets of 3 condensate trap openings. Each orientation will use 2 opening for drainage to the trap. The remaining opening will be plugged, as will the other set of 3 openings on the opposite corner of the collector box.
78Single Stage Pressure Switches Single stage furnaces have 2 pressure switchesHousing Pressure Switch (HPS)Tapped into Inducer HousingConnects electrically to the CPU of the furnace control boardCollector Box Pressure Switch (LPS)Tapped into Collector BoxConnects electrically to GVR via furnace control boardThe HPS has a lower set point than the LPSHPS functions as a blocked vent switchLPS functions as a blocked drain switch
79Single Stage Pressure Switches Note the label shows where the reference tube for the switch is connected to, either “COLLECTOR BOX-LPS” or “HOUSING-HPS”. The nominal break point is shown on each switch. There are different switches for different input furnaces. Use the exact replacement switch for the model furnace you are working on. The switches shown are for reference only
80Single Stage Wiring Diagram Refer to the legendHPSInducer Housing Pressure Switch, SPST (N.O.)LPSCollector Box Pressure Switch, SPST (N.O.)
81Single Stage Pressure Switches The switches are wired in parallel.
83Heat Exchanger Assembly Front View Primary cell panel is not shown in this image. This is the primary and secondary heat exchanger assembly.
84Heat Exchanger Assembly Rear View This is the rear view. Note how the flue gas flows from the inlet of the primary through the primary and secondary heat exchangers.DRAFT COPY - ICP CONFIDENTIAL
85Primary Assembly Completely redesigned heat exchanger The insulated primary cell panel is a one piece design that attaches to primary cell inlet plate. The snap-disk type limit switch attaches to an opening in the primary cell panel.Completely redesigned heat exchangerCompact multi-pass designAluminizedService replacement sold fully assembled to the Primary Cell Inlet Plate
86Condensing Heat Exchanger Fin and tube type designStainless steel tubesAluminum finsTubes are straight throughTurbulators are “locked” in each tube
87Burners, HSI and Flame Sensor One piece burner design for each sizeBurners are “ganged” togetherEliminates burner misalignmentNote igniter and flame sensor locationsIgniter mounts from the top of the burner assemblyFlame sensor mounts through tab on burnerFlame sensor is positioned underneath burnerIgniter resistance at room temp40 to 70 ohmsFlame sensing current4 to 6 micro amps DC
88Manifold Assembly Features (Top plate removed for clarity) Four screws attach manifold hereManifold is the same type for all families
89Burner AssemblyIgniter resistance is 40 to 70 room temperature and is stable over the life of the igniter
92Blower Assemblies Improved blower rails Forward-facing mounting screws Mounting Screw LocationsImproved blower railsForward-facing mounting screwsLonger main harness (not shown)Blower can be removed without harness removalForward-facing control board
93Torsion-Flex Blower Motors The torsion flex PSC motor is used in these modelsMounting arms attached to motorIsolated with rubber grommets
94Typical Blower Assembly (Expanded) This is the expanded view of the blower assembly. The blower wheel set screw torque is 160 in-lbs, +/- 20 in.-lbs
95Motor Mounting HolesThere are 2 sets of holes in the blower so if one set gets stripped, the whole motor can be rotated to the other set of holes.For example:One or more of the screws were stripped in the blower marked with a blue circle.Remove all 4 mounting screws, rotate the motor to the holes with the arrows and re-install the screws.
96Remember!Either set of screw holes can be used to mount the blower as long as…The same hole position is used for each mounting armDo not use a left-side hole for one mounting leg then a right side hole for another mounting leg.This stresses the mounting arms and can cause them to break
97Propane Conversion Regulator spring change required for all models Low Gas Pressure Switch (LGPS) required for ALL modelsBurners will use “Mixing Screws”1 screw is installed in each burner venturiProvide better mixing of propane and combustion airIncludes drill bit to drill the correct size holeA factory accessory conversion kit is required for installations using propane gas. Along with a regulator spring change in the gas valve, all propane installations require Mixing Screws in each burner venturi and a low gas pressure switch. Instructions are included in the conversion kit.
98Converting The Gas Valve The furnace is shipped with the gas valve configured for Natural Gas. In the propane conversion kit, there is a propane regulator spring. This spring allows the regulator in the valve to operate at the required pressure for propane. Note that the natural gas spring is silver and the propane spring is white. The approximate number of turns to pre-set the regulator spring are shown. Final adjustment must be made when starting the furnace.
100LGPS Installation 14 3/16” casing Or, vent passes across vestibule Install switch as shownManifold removedAdd wires to switchInstall manifoldA low gas pressure switch is used on the inlet pressure tap. The switch will shut down the furnace if the pressure in the propane tank falls below 7.2 in.-w.c.
101Low Gas Pressure Switch Installation The switch installation is covered in the propane conversion instructions.
102Low Gas Pressure Switch Installation Optional Location Additional fitting are supplied in the kit if more room is needed to install the switch.
104Control Board Features Single-stage PSC24vac Thermostat ConnectionsR, W, Y, GInducer Pre/Post Purge15 Sec/5 SecHeat On Delay25 SecEACYesHeat Off Delay90, 120, 150, 180Hum24 vac Q.C.Cool On Delay3 SecHum MethodWhen Pressure Switch ClosesCool Off Delay90 SecBlower SpeedsUp to 4 speed taps at motor, 2 are controlledOptional Cool Off DelayCut J1 Jumper (non reversible)Heat AirflowSelectable HeatComponent Self TestCool AirflowSelectable High Cool OnlyNon-Volatile MemoryContinuous FanSame as Heat
105Single-Stage PSC Control Component Layout All thermostat and accessory connections are made at the control board of the furnace.
106Optional 3-Second Cooling Off Delay CUT J2 JUMPER TO REDUCE90 SECOND COOLING OFF-DELAY TO 3 SECONDS(NON-REVERSIBLE)
107Single-Stage PSC Control Fan Speed Selection SELECT HEATING AND COOLING SPEEDS REQUIREDCONTINUOUS FAN SPEED IS HEATING SPEEDSTORE EXTRA SPEEDS ON SPARE 1 AND SPARE 2 TERMINALS
108Heating Off Delay Single-Stage Control 901201501802 PIN JUMPER: 1 TO 2 90 SECONDS 2 TO SECONDS3 TO SECONDS 4 TO SECONDS
109Single-Stage Control Component Self Test To initiate the component last sequence, shut OFF the room thermostat or disconnect the “R” thermostat lead.Briefly short the TEST/TWIN terminal to the COM/24V terminal (Red Arrow)Once initiated the Status LED will flash the last Status Code and then turn ON the inducerThe inducer motor will run for the entire component test.The hot surface igniter, blower motor FAN speed (if equipped), blower motor Heat speed and blower motor COOL speed will be turned ON for 15 seconds each.Gas Valve and Humidifier will not be turned on.
110Status Codes Code Description Heartbeat NO PREVIOUS CODE • Stored status codes are erased automatically after 72 hours or as specified above.2PRESSURE SWITCH DID NOT OPEN. Check for: Obstructed pressure switch tubing, Pressure switch stuck closed.3PRESSURE SWITCH DID NOT CLOSE OR RE-OPENED. Check for: If LPS is open longer than 6 minutes, inducer shuts off for 18 minutes before re-try. If HPS remains open for 72 seconds after the gas valve closes (after 3 successive trials) the furnace control will lockout for 3 ½ hours before re-try4LIMIT CIRCUIT FAULT. Indicates a limit or flame rollout switch is open. Blower will run for 4 minutes or until open switch remakes whichever is longer. If open longer than 3 minutes, code changes to lockout #7. If open less than 3 1/2 minutes status code #4 continues to flash until blower shuts off. Flame rollout switch requires manual reset. Check for: Dirty filter or restricted duct system-Improper limit switch or no limit gasket. Defective switch or connections- Improper gas input adjustment- Loose blower wheel5ABNORMAL FLAME PROVING SIGNAL, Flame is proved while gas valve is de-energized. Inducer will run until fault is cleared. Check for: Leaky gas valve; Stuck-open gas valve; Dirty flame sensor insulator6IGNITION PROVING FAULT -Control will try three more times before lockout #14 occurs. If flame signal lost during blower time limits. Thirty seconds after being turned ON or ten seconds during steady-state operation. Check for:- Oxide buildup on flame sensor (clean with fine steel wool) - Proper flame sense microamps (.5 microamps D.C. min., nominal) Manual valve shut-off- Control ground continuity- Gas valve defective fumed 'OFF'- Low inlet gas pressure-Defective hot surface igniter-Flame sensor must not be grounded-Green/yellow wire MUST be connected to furnace sheet metal.
111Status Codes Code Description 7 LIMIT CIRCUIT LOCKOUT. Lockout occurs If a limit or flame rollout switch is open longer than 3 ½ minutes. Control will auto-reset in 3 hrs. Refer to Code 4.8GAS HEATING LOCKOUT • Control will NOT auto reset.Check for - Mis-wired gas valve -Defective control (valve relay)9POLARITY Line voltage (220 VAC) polarity reversed.1 + 2BLOWER ON AFTER POWER UP (115VAC or 24VAC)- Blower runs for 90 seconds, if unit is powered up during a call for heat (R to W/W1 closed) or (R to W/W1) opens during the blower on delay period.6 + 1IGNITION LOCKOUT Control will auto reset in 3 ½ hours. Refer to Code 6OFFSECONDARY VOLTAGE FUSE IS OPEN • Check for - Short circuit in secondary voltage (24VAC) wiring.On (solid)CONTROL CIRCUITRY LOCKOUT Auto reset after 72 minutes. Lockout due to: Gas Valve relay stuck open. Flame sense circuitry failure. Software check error. Reset power to clear lockout. Replace control if status code repeats.
112Sequence Of OperationNOTE: Furnace control must be grounded for proper operation or control will lock out. Control is grounded through green/yellow wire routed to gas valve and manifold bracket screw. Using the schematic diagram in Fig. 64, follow the sequence of operation through the different modes. Read and follow the wiring diagram very carefully.NOTE: If a power interruption occurs during a call for heat (W), the control will start a 108–sec blower–only ON period two sec after power is restored, if the thermostat is still calling for gas heating. The Green LED light will flash Code 1+2 during the 108–sec period, after which the LED will be flashing a heartbeat, as long as no faults are detected. After the 108–sec period, the furnace will respond to the thermostat normally.
113The blower door must be installed for power to be conducted through the blower door interlock switch ILK to the furnace control CPU, transformer TRAN, inducer motor IDM, blower motor BLWM, hot–surface igniter HSI, and gas valve GV.
114ThermostatThermostatThe wall thermostat “calls for heat,” closing the R–to–W circuit. The furnace control performs a self–check, verifies the pressure switch contacts LPS and HPS are open, and starts the inducer motor IDM.
115ThermostatThermostatInducer Prepurge Period– As the inducer motor IDM comes up to speed, the HUM terminal is energized at 220v, and the low pressure switch contacts LPS close to begin an 18 second prepurge period, and 24 vac is supplied for a field installed humidifier at the HUM 24 vac terminal. The high pressure switch contacts HPS are ignored until one minute after the gas valve is energized.
116ThermostatThermostatIgniter Warm–Up– At the end of the prepurge period, the Hot–Surface igniter HSI is energized for a 20–sec igniterwarm–up period.Trial–for–Ignition Sequence– When the igniter warm–up period is completed, the main gas valve relay contacts GVR close to energize the gas valve GV, the gas valve opens. The gas valve GV permits gas flow to the burners where it is ignited by the HSI. Five sec after the GVR closes, a 2–sec flame proving period begins. The HSI igniter will remain energized until the flame is sensed oruntil the 2–sec flame proving period begins.Flame–Proving– When the burner flame is proved at the flame–proving sensor electrode FSE, the furnace control CPU begins the blower–ON delay period and continues to hold the gas valve GV open. If the burner flame is not proved within two sec, the control CPU will close the gas valve GV, and the control CPU will repeat the ignition sequence for up to three more Trials–For–Ignition before going to Ignition–Lockout.Lockout will be reset automatically after 3–1/2 hours or by momentarily interrupting 220 vac power to the furnace, or by interrupting 24 vac power at 24VAC or COM to the furnace control CPU (not at W, G, R, etc.). If flame is proved when flame should not be present, the furnace control CPU will lock out of Gas–Heating mode and operate the inducer motor IDM until flame is no longer proved.
117DRAFT COPY - ICP CONFIDENTIAL ThermostatThermostatBlower–On Delay– If the burner flame is proven, the blower motor is energized on HEAT speed 30 sec after thegas valve GV is energized. Simultaneously, the electronic air cleaner terminal EAC is energized and remains energized as long as the blower motor BLWM is energized.DRAFT COPY - ICP CONFIDENTIAL
118DRAFT COPY - ICP CONFIDENTIAL Heat–Off Delay– When the thermostat is satisfied, the R–to–W circuit is opened, de–energizing the gas valve GV, stopping gas flow to the burners, and de–energizing the humidifier terminal HUM24 VAC. The inducer motor IDM, and HUM terminal will remain energized for an 18–sec post–purge period. The blower motor BLWM and air cleaner terminal EAC will remain energized for 108, 144, 180, or 216 sec (depending on the heat–OFF delay selection). Note board selections are shown as 90, 120, 150, 180. The furnace control CPU is factory–set for a 144–sec heat–OFF delay.DRAFT COPY - ICP CONFIDENTIAL
119Start-upRefer to the installation instructions for specific start-up detailsStart-up procedures are:Verify installation is completeVerify the correct orifices are installedPrime the condensate trapPurge the gas supply lineCheck the inlet gas pressure
120Start-up Continued Start-up procedures (continued) are: Adjust the manifold pressureSet the temperature riseSet the blower off delaySet the cooling airflowCheck safety control operationReview installation checklist
121Priming The Condensate Trap 1. Remove upper and middle collector box drain plugs oppositeof the condensate trap.2. Connect field-supplied 5/8--in. (16 mm) ID tube with attached funnel to upper collector box drain connection.3. Pour one quart (liter) of water into funnel/tube. Water should run through collector box, overfill condensate trap,and flow into open field drain.4. Remove funnel; replace collector box drain plug.5. Connect field-supplied 5/8-in. (16 mm) ID tube to middle collector box drain port.6. Pour one quart (liter) of water into funnel/tube. Water should run through collector box, overfill condensate trap,7. Remove funnel and tube from collector box and replace collectorbox drain plug.
122Start-up Continued Start-up procedures are: Check the inlet gas pressureUse a good quality fluid-filled manometer to measure the inlet pressure at the gas valveSet the furnace to call for heatVerify inlet gas pressure does not drop below minimum inlet pressure4.5 IWC for Natural Gas12.0 for PropaneAdjust the manifold pressureManifold/orifice tables are providedUse a good quality fluid-filled manometer to measure the manifold pressure at the gas valveAdjust manifold pressure at the regulator of the gas valve
124Start-up Continued Start-up procedures (cont.) are: Set the temperature riseTemperature rise shown on the unit rating plateRun the furnace at steady stateMeasure the temperature in the supply air and the return airMeasure supply temperature away from the line of sight of the heat exchangerSubtract the return air temperature from the supply air temperatureChange blower speed to increase or decrease the temperature riseChange blower speed at the heating relay on the furnace control boardIdeal point is at the mid-point of the rise or slightly above the midpoint.
125Start-up procedures (cont.) are: Start-up ContinuedStart-up procedures (cont.) are:Set the blower off delayMove the jumper on the control board to the desired off delay timeSet the cooling airflowBlower airflow tables are in the installation instructions.Typical cooling speed is high speedChange motor speeds at the cooling relay on the furnace control board
126Single-Stage PSC Control Component Layout All thermostat and accessory connections are made at the control board of the furnace.
127Single-Stage PSC Control Fan Speed Selection SELECT HEATING AND COOLING SPEEDS REQUIREDCONTINUOUS FAN SPEED IS HEATING SPEEDSTORE EXTRA SPEEDS ON SPARE 1 AND SPARE 2 TERMINALS
128Heating Off Delay Single-Stage Control 901201501802 PIN JUMPER: 1 TO 2 90 SECONDS 2 TO SECONDS3 TO SECONDS 4 TO SECONDS
129Start-up Continued Start-up procedures (cont.) are: Check safety control operationPressure switch operationLimit switch operationFlame sensing circuitReview installation checklistThe safety controls are checked in the traditional manner, such as blocking the vent outlet to verify the pressure switch opens and shuts the furnace down. The limit is checked by slowly restricting the return air to the furnace until the limit switch opens. The flame sensor can be checked by removing the wire from the flame sensor, then setting the furnace to call for heat. After completing the installation and start up, review the installation instructions to verify the installation is complete.