HVAC / Free field reference
Trane Furnace Error Codes: S9V2 Quick Reference
Trane codes depend on the model and control board. This reference covers selected S9V2 faults from installer’s guide 18-CE01D1-1E-EN (2016), page 96. For example, E3.2 indicates an open first-stage pressure switch on that control.
Scope: Trane S9V2 models and control described in 18-CE01D1-1E-EN only. Match the unit label, board, and manual revision before using a code meaning. Other Trane furnaces, thermostats, and HVAC systems may use different codes.
Quick reference
| Code | Reported condition |
|---|---|
| E2.1 | Ignition retries exhausted; flame was not established. |
| E2.2 | Too many cycles with flame established and then lost. |
| E3.1 | First-stage pressure switch reported shorted. |
| E3.2 | First-stage pressure switch reported open. |
| E3.3 | Second-stage pressure switch reported shorted. |
| E3.4 | Second-stage pressure switch reported open. |
| E04 | An open limit circuit: thermal, rollout, or reverse-airflow switch. |
| E05 | Flame detected when it should be absent. |
Before you use the result
- Capture the model number, exact display, and symptoms for the service record. A fault identifies a reported condition; it does not prove that a particular part needs replacement.
- Do not bypass pressure, rollout, or limit switches, or repeatedly reset a furnace to keep it running. Electrical, gas, and combustion diagnosis belongs with a qualified HVAC technician.
- If you smell gas or a carbon monoxide alarm sounds, leave the building and contact emergency services or the gas utility from a safe location.
Sources & edition notes
This is an independent HandySuite reference. The linked publisher’s code or equipment documentation governs the work.
Common questions
Does E3.2 mean the pressure switch must be replaced?
No. The listed S9V2 control reports an open first-stage pressure switch. A technician must determine the cause using the correct unit manual.
Are Trane error codes universal?
No. Model families and control revisions differ. An unlisted code or unmatched model needs its own manufacturer documentation.