Lennox International Inc Understanding the Sequence of Operation for Gas Furnaces

Page 46

Troubleshooting: Heating Sequence of Operation (Continued)

HEATING SEQUENCE OF OPERATION

CONTINUED

THERMOSTAT CALLS FOR HEAT.

STATUS LED −− HEARTBEAT.

SEE BOX A.

FLAME SIGNAL ABOVE

(u1.40 microamps)

YES

YES

SINGLE−STAGE THERMOSTAT MODE (DIP SWITCH SET AT

YES

START SECOND−STAGE RECOGNITION ON DELAY (10 OR 15 MINUTES).

STATUS LED −− HEARTBEAT

ROLLOUT SWITCHES CLOSED?

YES

FIRST−STAGE (LOW FIRE)

PRESSURE SWITCH CLOSED?

NO

LOW FLAME SIGNAL

(Does not affect control operation) STATUS ERROR CODE 1 + 2.

TWO STAGE THERMOSTAT MODE (DIP SWITCH SET AT

YES

 

 

 

 

45−SECOND INDOOR BLOWER ON DELAY BEGINS.

 

 

 

 

 

STATUS LED −− HEARTBEAT.

 

 

 

 

 

YES

 

 

 

YES

 

 

 

NO

PRIMARY & SECONDARY LIMIT SWITCHES

 

 

 

 

 

CLOSED?

 

NO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INDOOR BLOWER ON.

 

 

 

 

 

 

 

YES

STATUS ERROR CODE 5 + 1. SEQUENCE HOLDS

 

 

UNTIL ROLLOUT SWITCH IS RESET AND MAIN

 

 

 

 

 

 

 

 

 

 

POWER IS INTERRUPTED OR THERMOSTAT

 

 

 

 

 

IS CYCLED OFF/ON FOR 3 SECOND MINIMUM.

 

YES

NO

NO

FIRST−STAGE HEAT DEMAND SATISFIED?

YES

GAS VALVE OFF, COMBUSTION AIR INDUCER

OFF FOLLOWING POST PURGE.

INDOOR BLOWER OFF WITH DELAY

STATUS LED −− PULSE

SECOND−STAGE HEAT DEMAND.

SECOND−STAGE HEAT DEMAND REQUIRED?

YES

SECOND STAGE PRESSURE SWITCH CLOSED?

ABNORMAL FLASH CODE.

NOTE − IF SECOND−STAGE PRESSURE SWITCH

WAS ORIGINALLY FOUND CLOSED,

ABNORMAL CODE WILL FLASH.

NO

YES

SECOND−STAGE 30−SECOND DELAY ON BEGINS.

STATUS LED −− HEARTBEAT.

YES

SECOND−STAGE COMBUSTION AIR INDUCER ON. SECOND−STAGE GAS VALVE ON. HIGH HEAT INDOOR BLOWER SPEED ON. STATUS LED −− HEARTBEAT.

YES

SECOND−STAGE PRESSURE SWITCH CLOSED

IN LESS THAN TEN (10) SECONDS?

STATUS LED −− HEARTBEAT

YES

CONTINUED ON NEXT PAGE

 

 

GAS VALVE OFF, COMBUSTION AIR INDUCER OFF,

 

 

 

INDOOR BLOWER ON.

 

 

 

 

 

 

STATUS ERROR CODE 3 + 1.

 

 

 

 

 

YES

 

 

 

 

 

 

HAS PRIMARY OR SECONDARY LIMIT

 

 

SWITCH CLOSED WITHIN 3 MINUTES?

 

 

 

(Indoor blower on low speed during 3−minute period)

 

 

 

 

 

 

 

NO

 

 

 

 

 

 

 

 

 

LIMIT SWITCH WATCHGUARD MODE.

 

 

 

GAS VALVE OFF, COMBUSTION AIR INDUCER OFF,

 

 

 

INDOOR BLOWER OFF WITH DELAY.

YES

 

 

STATUS ERROR CODE 4 + 5

 

 

 

 

 

IS 60−MINUTE RESET PERIOD COMPLETE?

 

 

 

 

 

 

 

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

 

 

 

INDOOR BLOWER OFF AFTER DELAY.

 

 

 

STATUS ERROR CODE 2 + 3. CONTROL RESTARTS

YES

 

 

IGNITION SEQUENCE IF PRESSURE SWITCH

 

 

 

CLOSES WITHIN 2−1/2 MINUTES.

 

 

 

 

 

 

 

SECOND−STAGE PRESSURE SWITCH CLOSED

NO

 

 

AT BEGINNING OF HEAT DEMAND?

 

 

 

 

 

STATUS ERROR CODE 2 + 6.

 

 

 

 

 

 

 

SECOND STAGE HEAT DEMAND

 

 

 

STATUS LED −− HEARTBEAT.

 

 

 

 

 

 

 

NO

 

 

 

RETURNS TO FIRST−STAGE HEAT MODE WHICH

 

 

 

CONTINUES UNTIL SECOND−STAGE PRESSURE

 

 

 

SWITCH CAN BE PROVEN or HEAT DEMAND IS

 

 

 

SATISFIED. FIVE (5) MINUTE WAIT PERIOD

 

NO

INITIATED BEFORE RETRY. WERE 5 ATTEMPTS

 

MADE FOR SECOND−STAGE HEAT?

 

 

 

YES

 

 

 

 

CONTINUES FIRST−STAGE HEATING DEMAND.

 

 

 

WILL NOT REATTEMPT SECOND−STAGE

 

 

 

HEATING DEMAND.

 

 

 

STATUS ERROR CODE 2 + 5.

 

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Contents Installation Instructions EL280UH Table of ContentsUnit Dimensions − inches mm Supply AIR OpeningParts Arrangement EL280UH Gas Furnace Safety InformationShipping and Packing List Use of Furnace as Construction Heater GeneralCombustion, Dilution & Ventilation Air Equipment in Confined Space ALL AIR from Inside Equipment in Confined Space Setting Equipment Return Air Bracket Filters Duct SystemVenting Upflow PositionHorizontal Left Position Horizontal Right PositionVent Connection Upflow and Horizontal Position Common Venting Using Metal−Lined Masonry Chimney −1/2 To these instructions and the provided venting tables. If Feet FAN + FAN FAN + NAT 130 Carbon Monoxide Poisoning Hazard Gas Piping Leum gasesHorizontal Applications Possible Gas Piping Configurations Electrical Interior MAKE−UP BOX InstallationElectrostatic Discharge ESD Page Field Wiring Applications OFF EL280UH Schematic Wiring Diagram Typical EL280UH Field Wiring Diagram TWO−STAGE Integrated ControlIntegrated Control For Your Safety Read Before Lighting Unit Start−UpProper Combustion Gas Pressure AdjustmentHigh Altitude Manifold Pressure Settings at all Altitudes Other Unit Adjustments Heat FAN-OFF Time in SecondsHeating Sequence of Operation Blower Data Pressure Bottom and One Side Service Electrical SHOCK, Fire Or Explosion HazardEL280UH BURNER, Combustion AIR Inducer Assembly Heat Exchanger RemovalPage Planned Service Repair Parts ListFlash Code Status / Error Description Integrated Control Diagnostic CodesLED Troubleshooting Heating Sequence of Operation On NextHeating Sequence of Operation U1.40 microamps Or Heat Demand is SATISFIED. a Five Troubleshooting Cooling Sequence of Operation Cooling Sequence of OperationTroubleshooting Continuous Fan Sequence of Operation Continuous LOW Speed FAN Sequence of OperationStart−Up & Performance Check List Unit Operation Cooling ModeTemperature Rise Drain Line
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Manual 7 pages 50.25 Kb

Elite Series Gas Furnace Upflow/Horizontal Air Discharge, EL280UH specifications

Lennox International Inc. has established itself as a leader in the heating and cooling industry, providing innovative solutions for both residential and commercial environments. One of their notable products is the EL280UH, a high-efficiency gas furnace designed to offer optimal comfort while minimizing energy consumption.

The EL280UH operates with an impressive Annual Fuel Utilization Efficiency (AFUE) rating of up to 80%. This efficiency rating means that 80% of the fuel consumed is converted into heat, making it a cost-effective option for homeowners looking to reduce their utility bills. The furnace’s design is tailored to deliver reliable warmth during the coldest months, ensuring a comfortable home environment.

A key feature of the EL280UH is its two-stage heating capability. This technology allows the furnace to operate at a lower heating output for less demanding conditions, which not only conserves energy but also helps maintain a more consistent temperature in the home. When the demand for heat increases, the furnace can seamlessly transition to its higher output setting, providing quick and effective heating when needed.

Additionally, the EL280UH is equipped with a durable cabinet that minimizes heat loss, enhancing overall performance. The design incorporates several sound-dampening features as well, which contributes to quieter operation, allowing homeowners to enjoy a serene indoor environment.

The furnace also includes an advanced control system that integrates easily with smart home technology. This feature enables users to monitor and adjust their heating settings from anywhere using a smartphone app, creating added convenience and control over home heating.

Safety is another paramount aspect of the EL280UH. It includes an integrated flame sensor and pressure switch, ensuring reliable operation while minimizing risks associated with furnace malfunctions. The design adheres to stringent safety standards, providing users with peace of mind.

In summary, the Lennox EL280UH furnace stands out for its high efficiency, advanced features, and commitment to user safety. Its two-stage heating capability, quiet operation, and smart home integration make it an excellent choice for homeowners looking to enhance their heating system while being energy-conscious. The EL280UH embodies Lennox's dedication to quality and innovation, ensuring that comfort and efficiency go hand in hand.