Trane ACONT900AC43UA Service Manual page 204

Alert Codes & Flowcharts
Troubleshooting Flowcharts
Variable Speed, 2-Stage Communicating Gas Furnace
Troubleshooting Flowchart Index - Variable Speed, 2-Stage
4) IFC Component Layout
4) LED Flash Codes
5) Getting started
6) 2 Flash Troubleshooting Retry and Recycle Lockout
7) Ignitor Positioning
8) 3 Flash Troubleshooting Pressure Switch Errors
9) 4 Flash Troubleshooting High Limit and Auxiliary Limit
10) 4 Flash Troubleshooting Roll Out Limit
11) 5 Flash Troubleshooting Flame Error
12) 6 Flash Troubleshooting Polarity and Ground Errors
13) 6 Flash Troubleshooting Ignitor and Triac Errors
14) 7 Flash Troubleshooting External Gas Valve Circuit Error
15) 8 Flash Troubleshooting Low Flame Sense Error
16) 10 Flash Troubleshooting Blower Comm and System Comm Errors
17) 10 Flash Troubleshooting No System Clock and 24V Comm Mismatch Errors
The following pages include troubleshooting flowcharts in
reference to the 80% communicating furnaces ONLY; using the
FAULT LED and the User Interface as starting points.
The information contained is for reference only and does not
cover all scenarios or problems that may be encountered by a
qualified field technician.
Only qualified technicians should should attempt to install,
troubleshoot, or repair this appliance. Failure to follow all
cautions and/or warnings could result in personal or property
damage; including death.
GF - J 4