Question 1

What does Trane 3 red flashes mean?

Accepted Answer

Three red flashes on a Trane furnace means the pressure switch did not close or is stuck open. This is typically caused by a failed inducer motor, blocked flue or condensate drain, a cracked inducer housing, or a failed pressure switch. Start by verifying the inducer motor runs and clearing any drain blockages.

Question 2

How do I reset a Trane furnace after lockout?

Accepted Answer

A Trane furnace showing 1 red flash is in lockout. Power cycle the furnace by turning off the breaker for 30 seconds. Before resetting, diagnose the root cause by checking the igniter condition and flame sensor. Repeated lockouts without diagnosis can damage components.

Question 3

What does a continuous red LED on a Trane furnace mean?

Accepted Answer

A continuous (solid) red LED on a Trane furnace indicates an internal control board failure. The control board will need to be replaced. This is different from a steady red light, which indicates an external safety device has tripped.

Question 4

Are American Standard and Trane error codes the same?

Accepted Answer

Yes. Trane and American Standard are manufactured by the same parent company (Trane Technologies). They share identical control boards and LED status codes, so all error codes listed here apply to both brands.

Code	Description	Common Cause	Fix
1 red flash	System lockout (retry or manual reset needed)	Failed ignition after multiple tries or recurrent fault condition	Power cycle to reset, diagnose root cause before resetting, check igniter and flame sensor
2 red flashes	Pressure switch stuck closed	Welded pressure switch contacts or wiring short	Replace pressure switch, check wiring for shorts
3 red flashes	Pressure switch did not close / stuck open	Inducer motor failure, blocked flue/condensate, failed pressure switch, or cracked inducer housing	Verify inducer motor runs, clear condensate drain, check flue for obstruction, test pressure switch
4 red flashes	High limit switch open	Low airflow, dirty filter, failed blower, or high gas pressure	Replace air filter, check blower operation, verify gas pressure
5 red flashes	Flame sensed without gas valve call	Leaking gas valve, residual flame, or faulty flame sensor circuit	Check gas valve for leak-through, verify flame sensor circuit
Continuous red	Internal control failure	Failed control board	Replace control board
Amber steady	Normal, waiting for call	Normal standby	No action needed
Amber flash	Call for heat active, system running	Normal operation	No action needed
Red steady	External lockout	External safety device tripped	Check all external safeties, check rollout switches

Trane Error Codes & Fault Codes

Detailed Code Reference

Frequently Asked Questions

What does Trane 3 red flashes mean?

How do I reset a Trane furnace after lockout?

What does a continuous red LED on a Trane furnace mean?

Are American Standard and Trane error codes the same?

Get ColdSnap Free