Trane Furnace Error Codes & Fix Guides
All FixCode Guide coverage for Trane furnace error codes: start with the complete code list, or jump to a deep-dive guide for a specific code. Everything is verified against Trane manufacturer documentation.
Guides in this section
Trane Furnace Error Codes List: Every Code ExplainedTrane Furnace 3 Flashes: What the Blinking Light Means & FixesTrane Furnace E09 Error Code: Meaning, Causes & FixTrane Furnace 5 Flashes: What the Blinking Light Means & FixesTrane Furnace 7 Flashes: What the Blinking Light Means & FixesHow to Reset Trane Furnace Error Codes
Most searched Trane furnace codes
| Code | Meaning |
|---|---|
| 3 Flashes | Pressure switch fault — the pressure switch did not close (or the inducer/vent proof failed) on Trane furnaces with LED blink diagnostics. |
| 5 Flashes | Flame sensed when no flame should be present — Trane's chart wording (UC-series installer's manual and the verified chart): '5 Flashes: Flame sensed when no flame should be present.' The flame sensor is reporting a flame at a time when the gas valve is not energised and no flame may exist. |
| 7 Flashes | Gas valve circuit error — Trane's chart wording is exactly that: '7 Flashes: Gas valve circuit error.' The integrated control has detected a fault in the electrical circuit between itself and the gas valve: the wiring, the valve's coil, or the control's own valve output. |
| E09 | Not a Trane-published furnace code — no Trane support page, installer guide or service document found defines "E09" for a Trane furnace. Trane's documented residential furnace languages are LED blink codes and worded thermostat alerts on communicating systems, so this page explains how to get E09 decoded honestly instead of inventing a meaning for it. |