Sears N9MP2100J20B1, N9MP2050B12B1, N9MP2080F16B1 Circulating Fan G Request, Heating W Request

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10. Sequence of Operation & Diagnostics

The following is the normal operating sequence for the control system.

Cooling (¥) Request:

24 VAC signals applied to Y & G terminals of EFT (electronic fan timer) control.

•Cool motor speed energized after 5 second Cool Fan On Delay time.

Y & G signals removed from EFT.

•Cool motor speed de-energized after 90 second Cool Fan Off Delay time.

Circulating Fan (G) Request:

24 VAC signals applied to G terminals of EFT control.

•Heat motor speed energized without delay.

G signal removed from EFT.

•Heat motor speed de-energized without delay.

Heating (W) Request:

24 VAC signals applied to W terminal of EFT control.

•Inducer motor turns on.

•The gas valve solenoid energizes.

•Following a 3 second prepurge delay, the pilot valve opens and the ignitor begins to warm up.

•After the pilot lights, the main burners energize and light.

•Timed from the opening of the main gas valve, the control will delay 30 seconds before switching the fan to Heat speed.

W signal removed from EFT.

•The gas valve de-energizes and the main burners go out.

•The inducer runs at its present speed for a 30 second postpurge period.

•Timed from the gas valve de-energizing, the Heat fan speed de-energizes after the selected Heat Fan Delay time expires.

Heating Request with Gas Supply Line Shut Off:

24 VAC signals applied to W terminal of EFT control.

•Inducer motor turns on.

•The gas valve solenoid energizes.

•Following a 3 second prepurge delay, the pilot valve opens and the ignitor begins to warm up.

•The ignitor glows red-hot for 30 seconds, then turns off.

•The igniter stays off for 25 seconds, then begins to warm-up again.

•The igniter glows red-hot for 30 seconds, then turns off.

•The pilot valve closes 3 seconds after the igniter de-energizes.

•The inducer de-energizes 5 seconds after the pilot valve closes.

•The SmartValve proceeds to soft lockout and flashes error code 6.

•The control exits soft lockout after 5 minutes and begins another ignition sequence.

44001 102004

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Contents SingleStage Table of ContentsThis page for future reference KeepYES NOE YESSafety Rules Location and Clearances InstallationFrozenWater Pipe Hazard Typical Downflow Installation Installation RequirementsTypical Upflow Installation Dimensions & Clearances Leveling Requirements Air Openings and Connecting DuctsCombustion Ventilation Air Example Venting and Combustion Air CheckUnusually Tight Construction Ventilation AirVent and Combustion Air Piping For Two Pipe InstallationSingle Pipe N9MP1 Models Direct Vent N9MP2 ModelsPiping Insulation Guidelines TocompensateforoxygenburnedSee.Confined Space InstallaContaminated Combustion Air Vent and Combustion Air Piping GuidelinesN9MP1 & *9MPD Models Sizing Combustion Air and Vent PipeVent Termination Clearances Carbon Monoxide POISONING, Fire and Explosion HazardClearance Description 440O110200415cmforappliances10,OOOBTUH3kW,12 Condensate Drain Trap Freeze Protection CondensateDrain TrapUpflow Installations Top Vent See Figure Upflow Installations Top VentUpflow Installations Vent thru Left Side See Figure UpflowInstallationsVentthru LeftSideSwitch Side ViewOnly All ModelsVentthru RightSideAll Models Vent thru Right Side See Figure Downflow Left Side Vent and Trap SeeFigure Inlet 4=Downflow Right Side Vent and Trap See Figure Downflow Right Side Vent and TrapPVC 3/4 Coupling & Clamps 112ID Drain Hose On SomeHorizontal Left-Thru Top See Horizontal Left Thru TopHorizontal Left-Side Vent Horizontal Left-Side Vent See FigureYellowor black Horizontal Right thru Top16ID Rubber Tube\\ Relief Tube ExtensionHorizontal Right Side Vent SeeFigure HorizontalRight-SideVentConnecting Vent and Combustion Air Piping Connecting Tee Trap to Condensate Trap and Main Drain LineOpen Tee Tee TrapProper Sealing Procedure for Combustion Connecting Vent Pipes and TerminationVent Pipe Connection Fire HazardHorizontal Termination Using Exterior RisersVertical Termination Vent Termination ShieldingConcentric Vent and Combustion Air Sidewall Termination Multi Vent Termination ClearancesSidewall Inlet Vent and Exhaust Air Termination CmbustincncentricRoof -AirTerminationventandSupply Pressure Manifold Gas Pressure AdjustmentGas Supply Pressure IAIternate Input Ratings, USA onlyPressure NaturalFor the 50,000, 75,000, 100,000 and 125,000 Btuh Models TaiGeneral Derating Rules High Altitude Air Pressure SwitchElectrical SHOCK, Fire or Explosion Hazard Changing OrificesManual shut- off Gas Piping RequirementsLow Pressure ValveInstallations Electrical WiringPower SupplyWiring Humidifier/Electronic Air CleanerFan Timer Connections Fan Delay DIP Switch SettingsReduced Furnacelife Hazard Mountedto eithertheleftorrightDuctwork and Filter InstallationSizing InsulationDownflow Furnace Installation Filter Installation using Optional Filter RackCombustible Floor Installation Downflow applications, unless installing on nonFurnace Subbase SubbasesforCombustibleFloorsDimensionsFloorDimensions Adjust Pilot Burner Checks and AdjustmentsGas SupplyPressure StartupHeating and Continuous BlowerSpeed Same Temperature Rise CheckChanging Blower Speed Reduced Furnace Life HazardFIRE, EXPLOSION, or Carbon Monoxide Hazards Furnace MaintenanceHeating Request with Gas Supply Line Shut Off Circulating Fan G RequestHeating W Request Typical Gas Valve Honeywell Gas Valve Diagnostic Codes See FigureOFF ThanHoneywell SV9541M Smart Valve Sequence of Operation Flashes Flashes + I Flash Honeywell SV9541M Smart Valve Trouble shootingLED IndicatesVent Termination Clearances Concentric TerminationConcentric Vent Termination Kit # LED INDICATESCHECK/REPAIRTicalterminationispreferredFieldsuppliedpipeandfittingsare RequiredtocompletetheinstallationConcentric Vent and Combustion Air Side Termination Rain Cap to Vent Pipe AssemblyTable for N9MP2 Models 50,000 & 80,000 Btuh Furnaces Roof Overhang25-22-02 Concentric Vent Sidewall AttachmentAir Elbow N9MP2100F14B1 N9MP2100J20B1 N9MP2125J20B1 N9MP2075B12B1 N9MP2080F16B1Denotes Brand 25-23-30General Model SpecificationsSpecifications N9MP1 Gas & Ignition Specifications N9MP2BlowerData Specifications 9MPDFor 075 Models 3 Ton Units For 050 Models 3 Ton UnitsFor 100 Models Ton 19 & 22314 Units For 080 Models 4 Ton 19 & 22314 UnitsNeutral t IlttlData UI I BKw25-23-95 Functional Key Description Part125J 100J 125J1GB Non-Functional14B 20B 12B 16B 14B16B 14B 20B 12B No. Non-FunctionalN9MP1 N9MP2 Osob Key DescriptionPart not Illustrated NAHF002LPNumber 080F12B 075F12B 080J16B 100J14B 9MPD100J20B 128L20B Capacitor,7.SMfd.,370VKeyDescription No.Non- Functional Parts *gMPDNumber 050F12B 078F12B 080J16B 100J14B 100J2OB 125L20BNon- Functional Part GMPDNumber 050F12B 075F12B 080J16BNon- Functional Number 1013816 + Order from Service Parts 44001050F12B 075F12B 080J16B 100J14B IOOJ20B

9MPD100J20B1, N9MP2100J20B1, 9MPD050F12B1, N9MP1100J20B1, N9MP1125J20B1 specifications

The Sears N9MP1075B12B1, N9MPD125L20B1, N9MP1050B12B1, N9MPD080J16B1, and N9MP2125J20B1 are part of the trusted line of gas furnaces manufactured by Sears, specifically designed to deliver reliable heating solutions for residential applications. These models incorporate cutting-edge technology and robust engineering, making them popular choices among homeowners looking for efficiency and comfort.

One of the main features of these models is their high-efficiency operation. With Annual Fuel Utilization Efficiency (AFUE) ratings exceeding 90%, these furnaces convert a significant portion of fuel into usable heat, thereby reducing energy costs. The N9MP series employs a multi-speed blower system that optimizes airflow for enhanced comfort while minimizing noise levels, ensuring a pleasant indoor environment.

The N9MPD125L20B1 and N9MPD080J16B1 variants highlight their adaptability through dual-stage heating capabilities. This technology allows the furnace to adjust its output based on the thermal demands of the home, preventing energy wastage during milder conditions while providing robust heating during extreme cold spells. The two-stage combustion process not only improves comfort but also contributes to lower greenhouse gas emissions.

Durability is another hallmark of these Sears models. With heavy-duty heat exchangers crafted from high-quality materials, they are built to withstand the rigors of regular use. Additionally, the inclusion of advanced safety mechanisms ensures that the system operates securely, reducing potential risks associated with gas furnaces.

The N9MP2125J20B1 model stands out due to its whisper-quiet operation. Homeowners can enjoy a warm home without the disruptive sound commonly associated with traditional heating systems, thanks to the insulated cabinet design and efficient blower operation.

Furthermore, these models come equipped with user-friendly digital thermostats, which allow precise temperature control and programmable settings, enabling homeowners to tailor their heating needs to fit their lifestyle. The compatibility with smart home systems also adds convenience, enabling users to manage their heating remotely, saving even more energy.

In conclusion, the Sears N9MP1075B12B1, N9MPD125L20B1, N9MP1050B12B1, N9MPD080J16B1, and N9MP2125J20B1 gas furnaces exemplify innovation in heating technology. Their energy-efficient designs, advanced features, and durable construction make them reliable choices for homeowners seeking comfort and sustainability in their heating solutions.
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