Table Of Contents - Lennox G24M SERIES Unit Information

Table of Contents

Specifications1
Service Literature1
Blower Data3
Parts Identification6
Heating Components6
G24M Burner Assembly7
G24M Blower Door Components7
I-Unit Components8
A-Blower Door Components8
Control Transformer8
Door Interlock Switch8
Surelight Control Board9
Diagnostic Codes9
Surelight Control Terminal Designations9
Flame Sensor To Burner Gap9
Electrostatic Discharge (Esd)10
Electronic Ignition10
Fan Time Control10
Fan-Off Time Adjustment10
Ram Control (A3)11
Ignition Control11
Early Model G24M Furnace Control (A3)12
.Krnace Control A3 Limit Response During Operation12
Diagnostic Led13
Blower Motors And Capacitors13
Furnace Control A3 Terminal Designations13
Furnace Control A3 Diagnostic Led13
Combustion Air Blower14
Flame Rollout Switches14
Primary Limit Control14
Secondary Limit Controls14
Gas Valve15
Typical Burner/Electrode Orientation15
Spark Electrode To Burner Gap15
Typical Access To Regulator For Adjustment And L.p. Changeover15
Start-Up16
Preliminary And Seasonal Checks16
Heating Start-Up16
Safety Or Emergency Shutdown16
Placement And Installation16
Heating System Service Checks17
A.g.a./C.g.a. Certification17
Gas Piping17
Testing Gas Piping17
Proper Gas Flow18
High Altitude Derate18
Flame Signal18
To Measure Flame Signal18
Typical Operating Characteristics19
Blower Operation And Adjustment19
Temperature Rise19
External Static Pressure19
Blower Speed Taps Leadless Motors20
Maintenance20
Blower Speed Taps Leaded Motors20
Heat Exchanger And Burners20
Supply Air Blower21
Flue And Chimney21
Electrical21
Heat Exchanger Removal21
Wiring, Operation Sequence22
Troubleshooting22
Field Wiring, Thermostat Connections22
Early Model G24M Series With Ram Ignition Control23
Ram Ignition Control Troubleshooting Guide24
Ram Control Heating Trouble Shooting Sequence24
Late Model G24M Series With Surelight Ignition Control26
Typical G24M Diagram26
Surelight Control Heating Sequence Of Operation27
Normal Heating Mode27
Abnormal Heating Mode27
Surelight Control Cooling Sequence29
Continuous Low Speed Fan Sequence Of Operation30
Surelight Ignition Control Troubleshooting Guide31
Unit Fails To Operate In The Cooling, Heating, Or Continuous Fan Mode31
Pressure Switch34
Control Signals Low Flame Sense During Heating Mode36
Rf Static During Time For Ignition36